13.6.0-2

Remove broken link to terminated cattaz website

.bowerrc

@@ -1,3 +0,0 @@
-{
- "directory": "../"
-}

.circleci/config.yml

@@ -0,0 +1,7 @@
+version: 2.1
+orbs:
+  node: circleci/node@3.0.0
+workflows:
+  node-tests:
+    jobs:
+      - node/test

.github/workflows/node.js.yml

@@ -0,0 +1,29 @@
+# This workflow will do a clean install of node dependencies, build the source code and run tests across different versions of node
+# For more information see: https://help.github.com/actions/language-and-framework-guides/using-nodejs-with-github-actions
+
+name: Node.js CI
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [10.x, 12.x, 14.x]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v1
+      with:
+        node-version: ${{ matrix.node-version }}
+    - run: npm ci
+    - run: npm run build --if-present
+    - run: npm test

.github/workflows/nodejs.yml

@@ -0,0 +1,31 @@
+# This workflow will do a clean install of node dependencies, build the source code and run tests across different versions of node
+# For more information see: https://help.github.com/actions/language-and-framework-guides/using-nodejs-with-github-actions
+
+name: Node.js CI
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [10.x, 12.x, 13.x]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v1
+      with:
+        node-version: ${{ matrix.node-version }}
+    - run: npm ci
+    - run: npm run lint
+    - run: npm run test-extensive
+      env:
+        CI: true

.gitignore

@@ -1,6 +1,4 @@
-/node_modules/
-bower_components
-.directory
-.c9
-.codio
-.settings
+node_modules
+dist
+.vscode
+docs

.jsdoc.json

@@ -0,0 +1,52 @@
+{
+  "sourceType": "module",
+  "tags": {
+    "allowUnknownTags": true,
+    "dictionaries": ["jsdoc"]
+  },
+  "source": {
+    "include": ["./src"],
+    "includePattern": ".js$"
+  },
+  "plugins": [
+    "plugins/markdown"
+  ],
+  "templates": {
+    "referenceTitle": "Yjs",
+    "disableSort": false,
+    "useCollapsibles": true,
+    "collapse": true,
+    "resources": {
+      "yjs.dev": "Website",
+      "docs.yjs.dev": "Docs",
+      "discuss.yjs.dev": "Forum",
+      "https://gitter.im/Yjs/community": "Chat"
+    },
+    "logo": {
+      "url": "https://yjs.dev/images/logo/yjs-512x512.png",
+      "width": "162px",
+      "height": "162px",
+      "link": "/"
+    },
+    "tabNames": {
+      "api": "API",
+      "tutorials": "Examples"
+    },
+    "footerText": "Shared Editing",
+    "css": [
+      "./style.css"
+    ],
+    "default": {
+      "staticFiles": {
+          "include": []
+      }
+    }
+  },
+  "opts": {
+    "destination": "./docs/",
+    "encoding": "utf8",
+    "private": false,
+    "recurse": true,
+    "template": "./node_modules/tui-jsdoc-template"
+  }
+}

.markdownlint.json

@@ -0,0 +1,4 @@
+{
+  "default": true,
+  "no-inline-html": false
+}

INTERNALS.md

@@ -0,0 +1,179 @@
+# Yjs Internals
+
+This document roughly explains how Yjs works internally. There is a complete
+walkthrough of the Yjs codebase available as a recording:
+https://youtu.be/0l5XgnQ6rB4
+
+The Yjs CRDT algorithm is described in the [YATA
+paper](https://www.researchgate.net/publication/310212186_Near_Real-Time_Peer-to-Peer_Shared_Editing_on_Extensible_Data_Types)
+from 2016. For an algorithmic view of how it works, the paper is a reasonable
+place to start. There are a handful of small improvements implemented in Yjs
+which aren't described in the paper. The most notable is that items have an
+`originRight` as well as an `origin` property, which improves performance when
+many concurrent inserts happen after the same character.
+
+At its heart, Yjs is a list CRDT. Everything is squeezed into a list in order to
+reuse the CRDT resolution algorithm:
+
+- Arrays are easy - they're lists of arbitrary items.
+- Text is a list of characters, optionally punctuated by formatting markers and
+  embeds for rich text support. Several characters can be wrapped in a single
+linked list `Item` (this is also known as the compound representation of
+CRDTs). More information about this in [this blog
+article](https://blog.kevinjahns.de/are-crdts-suitable-for-shared-editing/).
+- Maps are lists of entries. The last inserted entry for each key is used, and
+  all other duplicates for each key are flagged as deleted.
+
+Each client is assigned a unique *clientID* property on first insert. This is a
+random 53-bit integer (53 bits because that fits in the javascript safe integer
+range).
+
+## List items
+
+Each item in a Yjs list is made up of two objects:
+
+- An `Item` (*src/structs/Item.js*). This is used to relate the item to other
+  adjacent items.
+- An object in the `AbstractType` hierarchy (subclasses of
+  *src/types/AbstractType.js* - eg `YText`). This stores the actual content in
+the Yjs document.
+
+The item and type object pair have a 1-1 mapping. The item's `content` field
+references the AbstractType object and the AbstractType object's `_item` field
+references the item.
+
+Everything inserted in a Yjs document is given a unique ID, formed from a
+*ID(clientID, clock)* pair (also known as a [Lamport
+Timestamp](https://en.wikipedia.org/wiki/Lamport_timestamp)). The clock counts
+up from 0 with the first inserted character or item a client makes. This is
+similar to automerge's operation IDs, but note that the clock is only
+incremented by inserts. Deletes are handled in a very different way (see
+below).
+
+If a run of characters is inserted into a document (eg `"abc"`), the clock will
+be incremented for each character (eg 3 times here). But Yjs will only add a
+single `Item` into the list. This has no effect on the core CRDT algorithm, but
+the optimization dramatically decreases the number of javascript objects
+created during normal text editing. This optimization only applies if the
+characters share the same clientID, they're inserted in order, and all
+characters have either been deleted or all characters are not deleted. The item
+will be split if the run is interrupted for any reason (eg a character in the
+middle of the run is deleted).
+
+When an item is created, it stores a reference to the IDs of the preceeding and
+succeeding item. These are stored in the item's `origin` and `originRight`
+fields, respectively. These are used when peers concurrently insert at the same
+location in a document. Though quite rare in practice, Yjs needs to make sure
+the list items always resolve to the same order on all peers. The actual logic
+is relatively simple - its only a couple dozen lines of code and it lives in
+the `Item#integrate()` method. The YATA paper has much more detail on the this
+algorithm.
+
+### Item Storage
+
+The items themselves are stored in two data structures and a cache:
+
+- The items are stored in a tree of doubly-linked lists in *document order*.
+  Each item has `left` and `right` properties linking to its siblings in the
+document. Items also have a `parent` property to reference their parent in the
+document tree (null at the root). (And you can access an item's children, if
+any, through `item.content`).
+- All items are referenced in *insertion order* inside the struct store
+  (*src/utils/StructStore.js*). This references the list of items inserted by
+for each client, in chronological order. This is used to find an item in the
+tree with a given ID (using a binary search). It is also used to efficiently
+gather the operations a peer is missing during sync (more on this below).
+
+When a local insert happens, Yjs needs to map the insert position in the
+document (eg position 1000) to an ID. With just the linked list, this would
+require a slow O(n) linear scan of the list. But when editing a document, most
+inserts are either at the same position as the last insert, or nearby. To
+improve performance, Yjs stores a cache of the 10 most recently looked up
+insert positions in the document. This is consulted and updated when a position
+is looked up to improve performance in the average case. The cache is updated
+using a heuristic that is still changing (currently, it is updated when a new
+position significantly diverges from existing markers in the cache). Internally
+this is referred to as the skip list / fast search marker.
+
+### Deletions
+
+Deletions in Yjs are treated very differently from insertions. Insertions are
+implemented as a sequential operation based CRDT, but deletions are treated as
+a simpler state based CRDT.
+
+When an item has been deleted by any peer, at any point in history, it is
+flagged as deleted on the item. (Internally Yjs uses the `info` bitfield.) Yjs
+does not record metadata about a deletion:
+
+- No data is kept on *when* an item was deleted, or which user deleted it.
+- The struct store does not contain deletion records
+- The clientID's clock is not incremented
+
+If garbage collection is enabled in Yjs, when an object is deleted its content
+is discarded. If a deleted object contains children (eg a field is deleted in
+an object), the content is replaced with a `GC` object (*src/structs/GC.js*).
+This is a very lightweight structure - it only stores the length of the removed
+content.
+
+Yjs has some special logic to share which content in a document has been
+deleted:
+
+- When a delete happens, as well as marking the item, the deleted IDs are
+  listed locally within the transaction. (See below for more information about
+transactions.) When a transaction has been committed locally, the set of
+deleted items is appended to a transaction's update message.
+- A snapshot (a marked point in time in the Yjs history) is specified using
+  both the set of (clientID, clock) pairs *and* the set of all deleted item
+IDs. The deleted set is O(n), but because deletions usually happen in runs,
+this data set is usually tiny in practice. (The real world editing trace from
+the B4 benchmark document contains 182k inserts and 77k deleted characters. The
+deleted set size in a snapshot is only 4.5Kb).
+
+## Transactions
+
+All updates in Yjs happen within a *transaction*. (Defined in
+*src/utils/Transaction.js*.)
+
+The transaction collects a set of updates to the Yjs document to be applied on
+remote peers atomically. Once a transaction has been committed locally, it
+generates a compressed *update message* which is broadcast to synchronized
+remote peers to notify them of the local change. The update message contains:
+
+- The set of newly inserted items
+- The set of items deleted within the transaction.
+
+## Network protocol
+
+The network protocol is not really a part of Yjs. There are a few relevant
+concepts that can be used to create a custom network protocol:
+
+* `update`: The Yjs document can be encoded to an *update* object that can be
+  parsed to reconstruct the document. Also every change on the document fires
+an incremental document updates that allows clients to sync with each other.
+The update object is an Uint8Array that efficiently encodes `Item` objects and
+the delete set.
+* `state vector`: A state vector defines the know state of each user (a set of
+  tubles `(client, clock)`). This object is also efficiently encoded as a
+Uint8Array.
+
+The client can ask a remote client for missing document updates by sending
+their state vector (often referred to as *sync step 1*). The remote peer can
+compute the missing `Item` objects using the `clocks` of the respective clients
+and compute a minimal update message that reflects all missing updates (sync
+step 2).
+
+An implementation of the syncing process is in
+[y-protocols](https://github.com/yjs/y-protocols).
+
+## Snapshots
+
+A snapshot can be used to restore an old document state. It is a `state vector`
+\+ `delete set`. I client can restore an old document state by iterating through
+the sequence CRDT and ignoring all Items that have an `id.clock >
+stateVector[id.client].clock`. Instead of using `item.deleted` the client will
+use the delete set to find out if an item was deleted or not.
+
+It is not recommended to restore an old document state using snapshots,
+although that would certainly be possible. Instead, the old state should be
+computed by iterating through the newest state and using the additional
+information from the state vector.

LICENSE

@@ -1,6 +1,8 @@
 The MIT License (MIT)
 
-Copyright (c) 2014 Kevin Jahns <kevin.jahns@rwth-aachen.de>.
+Copyright (c) 2014
+  - Kevin Jahns <kevin.jahns@rwth-aachen.de>.
+  - Chair of Computer Science 5 (Databases & Information Systems), RWTH Aachen University, Germany
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

bower.json

@@ -1,33 +0,0 @@
-{
-  "name": "yjs",
-  "version": "0.3.0",
-  "homepage": "https://github.com/DadaMonad/yjs",
-  "authors": [
-    "Kevin Jahns <kevin.jahns@rwth-aachen.de>"
-  ],
-  "description": "A Framework that enables Real-Time collaboration on arbitrary data structures.",
-  "main": [
-    "./y.js",
-    "./y-object.html",
-    "./build/node/y.js"
-  ],
-  "keywords": [
-    "OT",
-    "collaboration",
-    "synchronization",
-    "ShareJS",
-    "Coweb",
-    "concurrency"
-  ],
-  "license": "MIT",
-  "ignore": [
-    "node_modules",
-    "bower_components",
-    "test",
-    "extras",
-    "test"
-  ],
-  "dependencies": {
-    "polymer": "Polymer/polymer#~0.5.3"
-  }
-}

build/node/ConnectorAdapter.js

@@ -1,68 +0,0 @@
-var adaptConnector;
-
-adaptConnector = function(connector, engine, HB, execution_listener) {
-  var applyHB, encode_state_vector, getHB, getStateVector, parse_state_vector, send_;
-  send_ = function(o) {
-    if (o.uid.creator === HB.getUserId() && (typeof o.uid.op_number !== "string")) {
-      return connector.broadcast(o);
-    }
-  };
-  if (connector.invokeSync != null) {
-    HB.setInvokeSyncHandler(connector.invokeSync);
-  }
-  execution_listener.push(send_);
-  encode_state_vector = function(v) {
-    var name, value, _results;
-    _results = [];
-    for (name in v) {
-      value = v[name];
-      _results.push({
-        user: name,
-        state: value
-      });
-    }
-    return _results;
-  };
-  parse_state_vector = function(v) {
-    var s, state_vector, _i, _len;
-    state_vector = {};
-    for (_i = 0, _len = v.length; _i < _len; _i++) {
-      s = v[_i];
-      state_vector[s.user] = s.state;
-    }
-    return state_vector;
-  };
-  getStateVector = function() {
-    return encode_state_vector(HB.getOperationCounter());
-  };
-  getHB = function(v) {
-    var hb, json, o, state_vector, _i, _len;
-    state_vector = parse_state_vector(v);
-    hb = HB._encode(state_vector);
-    for (_i = 0, _len = hb.length; _i < _len; _i++) {
-      o = hb[_i];
-      o.fromHB = "true";
-    }
-    json = {
-      hb: hb,
-      state_vector: encode_state_vector(HB.getOperationCounter())
-    };
-    return json;
-  };
-  applyHB = function(hb) {
-    return engine.applyOp(hb);
-  };
-  connector.getStateVector = getStateVector;
-  connector.getHB = getHB;
-  connector.applyHB = applyHB;
-  connector.whenReceiving(function(sender, op) {
-    if (op.uid.creator !== HB.getUserId()) {
-      return engine.applyOp(op);
-    }
-  });
-  if (connector._whenBoundToY != null) {
-    return connector._whenBoundToY();
-  }
-};
-
-module.exports = adaptConnector;

build/node/Engine.js

@@ -1,113 +0,0 @@
-var Engine;
-
-if (typeof window !== "undefined" && window !== null) {
-  window.unprocessed_counter = 0;
-}
-
-if (typeof window !== "undefined" && window !== null) {
-  window.unprocessed_exec_counter = 0;
-}
-
-if (typeof window !== "undefined" && window !== null) {
-  window.unprocessed_types = [];
-}
-
-Engine = (function() {
-  function Engine(HB, types) {
-    this.HB = HB;
-    this.types = types;
-    this.unprocessed_ops = [];
-  }
-
-  Engine.prototype.parseOperation = function(json) {
-    var type;
-    type = this.types[json.type];
-    if ((type != null ? type.parse : void 0) != null) {
-      return type.parse(json);
-    } else {
-      throw new Error("You forgot to specify a parser for type " + json.type + ". The message is " + (JSON.stringify(json)) + ".");
-    }
-  };
-
-
-  /*
-  applyOpsBundle: (ops_json)->
-    ops = []
-    for o in ops_json
-      ops.push @parseOperation o
-    for o in ops
-      if not o.execute()
-        @unprocessed_ops.push o
-    @tryUnprocessed()
-   */
-
-  Engine.prototype.applyOpsCheckDouble = function(ops_json) {
-    var o, _i, _len, _results;
-    _results = [];
-    for (_i = 0, _len = ops_json.length; _i < _len; _i++) {
-      o = ops_json[_i];
-      if (this.HB.getOperation(o.uid) == null) {
-        _results.push(this.applyOp(o));
-      } else {
-        _results.push(void 0);
-      }
-    }
-    return _results;
-  };
-
-  Engine.prototype.applyOps = function(ops_json) {
-    return this.applyOp(ops_json);
-  };
-
-  Engine.prototype.applyOp = function(op_json_array) {
-    var o, op_json, _i, _len;
-    if (op_json_array.constructor !== Array) {
-      op_json_array = [op_json_array];
-    }
-    for (_i = 0, _len = op_json_array.length; _i < _len; _i++) {
-      op_json = op_json_array[_i];
-      o = this.parseOperation(op_json);
-      if (op_json.fromHB != null) {
-        o.fromHB = op_json.fromHB;
-      }
-      if (this.HB.getOperation(o) != null) {
-
-      } else if (((!this.HB.isExpectedOperation(o)) && (o.fromHB == null)) || (!o.execute())) {
-        this.unprocessed_ops.push(o);
-        if (typeof window !== "undefined" && window !== null) {
-          window.unprocessed_types.push(o.type);
-        }
-      }
-    }
-    return this.tryUnprocessed();
-  };
-
-  Engine.prototype.tryUnprocessed = function() {
-    var old_length, op, unprocessed, _i, _len, _ref;
-    while (true) {
-      old_length = this.unprocessed_ops.length;
-      unprocessed = [];
-      _ref = this.unprocessed_ops;
-      for (_i = 0, _len = _ref.length; _i < _len; _i++) {
-        op = _ref[_i];
-        if (this.HB.getOperation(op) != null) {
-
-        } else if ((!this.HB.isExpectedOperation(op) && (op.fromHB == null)) || (!op.execute())) {
-          unprocessed.push(op);
-        }
-      }
-      this.unprocessed_ops = unprocessed;
-      if (this.unprocessed_ops.length === old_length) {
-        break;
-      }
-    }
-    if (this.unprocessed_ops.length !== 0) {
-      return this.HB.invokeSync();
-    }
-  };
-
-  return Engine;
-
-})();
-
-module.exports = Engine;

build/node/HistoryBuffer.js

@@ -1,250 +0,0 @@
-var HistoryBuffer,
-  __bind = function(fn, me){ return function(){ return fn.apply(me, arguments); }; };
-
-HistoryBuffer = (function() {
-  function HistoryBuffer(user_id) {
-    this.user_id = user_id;
-    this.emptyGarbage = __bind(this.emptyGarbage, this);
-    this.operation_counter = {};
-    this.buffer = {};
-    this.change_listeners = [];
-    this.garbage = [];
-    this.trash = [];
-    this.performGarbageCollection = true;
-    this.garbageCollectTimeout = 30000;
-    this.reserved_identifier_counter = 0;
-    setTimeout(this.emptyGarbage, this.garbageCollectTimeout);
-  }
-
-  HistoryBuffer.prototype.resetUserId = function(id) {
-    var o, o_name, own;
-    own = this.buffer[this.user_id];
-    if (own != null) {
-      for (o_name in own) {
-        o = own[o_name];
-        o.uid.creator = id;
-      }
-      if (this.buffer[id] != null) {
-        throw new Error("You are re-assigning an old user id - this is not (yet) possible!");
-      }
-      this.buffer[id] = own;
-      delete this.buffer[this.user_id];
-    }
-    this.operation_counter[id] = this.operation_counter[this.user_id];
-    delete this.operation_counter[this.user_id];
-    return this.user_id = id;
-  };
-
-  HistoryBuffer.prototype.emptyGarbage = function() {
-    var o, _i, _len, _ref;
-    _ref = this.garbage;
-    for (_i = 0, _len = _ref.length; _i < _len; _i++) {
-      o = _ref[_i];
-      if (typeof o.cleanup === "function") {
-        o.cleanup();
-      }
-    }
-    this.garbage = this.trash;
-    this.trash = [];
-    if (this.garbageCollectTimeout !== -1) {
-      this.garbageCollectTimeoutId = setTimeout(this.emptyGarbage, this.garbageCollectTimeout);
-    }
-    return void 0;
-  };
-
-  HistoryBuffer.prototype.getUserId = function() {
-    return this.user_id;
-  };
-
-  HistoryBuffer.prototype.addToGarbageCollector = function() {
-    var o, _i, _len, _results;
-    if (this.performGarbageCollection) {
-      _results = [];
-      for (_i = 0, _len = arguments.length; _i < _len; _i++) {
-        o = arguments[_i];
-        if (o != null) {
-          _results.push(this.garbage.push(o));
-        } else {
-          _results.push(void 0);
-        }
-      }
-      return _results;
-    }
-  };
-
-  HistoryBuffer.prototype.stopGarbageCollection = function() {
-    this.performGarbageCollection = false;
-    this.setManualGarbageCollect();
-    this.garbage = [];
-    return this.trash = [];
-  };
-
-  HistoryBuffer.prototype.setManualGarbageCollect = function() {
-    this.garbageCollectTimeout = -1;
-    clearTimeout(this.garbageCollectTimeoutId);
-    return this.garbageCollectTimeoutId = void 0;
-  };
-
-  HistoryBuffer.prototype.setGarbageCollectTimeout = function(garbageCollectTimeout) {
-    this.garbageCollectTimeout = garbageCollectTimeout;
-  };
-
-  HistoryBuffer.prototype.getReservedUniqueIdentifier = function() {
-    return {
-      creator: '_',
-      op_number: "_" + (this.reserved_identifier_counter++),
-      doSync: false
-    };
-  };
-
-  HistoryBuffer.prototype.getOperationCounter = function(user_id) {
-    var ctn, res, user, _ref;
-    if (user_id == null) {
-      res = {};
-      _ref = this.operation_counter;
-      for (user in _ref) {
-        ctn = _ref[user];
-        res[user] = ctn;
-      }
-      return res;
-    } else {
-      return this.operation_counter[user_id];
-    }
-  };
-
-  HistoryBuffer.prototype.isExpectedOperation = function(o) {
-    var _base, _name;
-    if ((_base = this.operation_counter)[_name = o.uid.creator] == null) {
-      _base[_name] = 0;
-    }
-    o.uid.op_number <= this.operation_counter[o.uid.creator];
-    return true;
-  };
-
-  HistoryBuffer.prototype._encode = function(state_vector) {
-    var json, o, o_json, o_next, o_number, o_prev, u_name, unknown, user, _ref;
-    if (state_vector == null) {
-      state_vector = {};
-    }
-    json = [];
-    unknown = function(user, o_number) {
-      if ((user == null) || (o_number == null)) {
-        throw new Error("dah!");
-      }
-      return (state_vector[user] == null) || state_vector[user] <= o_number;
-    };
-    _ref = this.buffer;
-    for (u_name in _ref) {
-      user = _ref[u_name];
-      for (o_number in user) {
-        o = user[o_number];
-        if (o.uid.doSync && unknown(u_name, o_number)) {
-          o_json = o._encode();
-          if (o.next_cl != null) {
-            o_next = o.next_cl;
-            while ((o_next.next_cl != null) && unknown(o_next.uid.creator, o_next.uid.op_number)) {
-              o_next = o_next.next_cl;
-            }
-            o_json.next = o_next.getUid();
-          } else if (o.prev_cl != null) {
-            o_prev = o.prev_cl;
-            while ((o_prev.prev_cl != null) && unknown(o_prev.uid.creator, o_prev.uid.op_number)) {
-              o_prev = o_prev.prev_cl;
-            }
-            o_json.prev = o_prev.getUid();
-          }
-          json.push(o_json);
-        }
-      }
-    }
-    return json;
-  };
-
-  HistoryBuffer.prototype.getNextOperationIdentifier = function(user_id) {
-    var uid;
-    if (user_id == null) {
-      user_id = this.user_id;
-    }
-    if (this.operation_counter[user_id] == null) {
-      this.operation_counter[user_id] = 0;
-    }
-    uid = {
-      'creator': user_id,
-      'op_number': this.operation_counter[user_id],
-      'doSync': true
-    };
-    this.operation_counter[user_id]++;
-    return uid;
-  };
-
-  HistoryBuffer.prototype.getOperation = function(uid) {
-    var o, _ref;
-    if (uid.uid != null) {
-      uid = uid.uid;
-    }
-    o = (_ref = this.buffer[uid.creator]) != null ? _ref[uid.op_number] : void 0;
-    if ((uid.sub != null) && (o != null)) {
-      return o.retrieveSub(uid.sub);
-    } else {
-      return o;
-    }
-  };
-
-  HistoryBuffer.prototype.addOperation = function(o) {
-    if (this.buffer[o.uid.creator] == null) {
-      this.buffer[o.uid.creator] = {};
-    }
-    if (this.buffer[o.uid.creator][o.uid.op_number] != null) {
-      throw new Error("You must not overwrite operations!");
-    }
-    if ((o.uid.op_number.constructor !== String) && (!this.isExpectedOperation(o)) && (o.fromHB == null)) {
-      throw new Error("this operation was not expected!");
-    }
-    this.addToCounter(o);
-    this.buffer[o.uid.creator][o.uid.op_number] = o;
-    return o;
-  };
-
-  HistoryBuffer.prototype.removeOperation = function(o) {
-    var _ref;
-    return (_ref = this.buffer[o.uid.creator]) != null ? delete _ref[o.uid.op_number] : void 0;
-  };
-
-  HistoryBuffer.prototype.setInvokeSyncHandler = function(f) {
-    return this.invokeSync = f;
-  };
-
-  HistoryBuffer.prototype.invokeSync = function() {};
-
-  HistoryBuffer.prototype.renewStateVector = function(state_vector) {
-    var state, user, _results;
-    _results = [];
-    for (user in state_vector) {
-      state = state_vector[user];
-      if ((this.operation_counter[user] == null) || (this.operation_counter[user] < state_vector[user])) {
-        _results.push(this.operation_counter[user] = state_vector[user]);
-      } else {
-        _results.push(void 0);
-      }
-    }
-    return _results;
-  };
-
-  HistoryBuffer.prototype.addToCounter = function(o) {
-    if (this.operation_counter[o.uid.creator] == null) {
-      this.operation_counter[o.uid.creator] = 0;
-    }
-    if (typeof o.uid.op_number === 'number' && o.uid.creator !== this.getUserId()) {
-      if (o.uid.op_number === this.operation_counter[o.uid.creator]) {
-        return this.operation_counter[o.uid.creator]++;
-      } else {
-        return this.invokeSync(o.uid.creator);
-      }
-    }
-  };
-
-  return HistoryBuffer;
-
-})();
-
-module.exports = HistoryBuffer;

build/node/Types/BasicTypes.js

@@ -1,487 +0,0 @@
-var __slice = [].slice,
-  __hasProp = {}.hasOwnProperty,
-  __extends = function(child, parent) { for (var key in parent) { if (__hasProp.call(parent, key)) child[key] = parent[key]; } function ctor() { this.constructor = child; } ctor.prototype = parent.prototype; child.prototype = new ctor(); child.__super__ = parent.prototype; return child; };
-
-module.exports = function(HB) {
-  var execution_listener, types;
-  types = {};
-  execution_listener = [];
-  types.Operation = (function() {
-    function Operation(uid) {
-      this.is_deleted = false;
-      this.garbage_collected = false;
-      this.event_listeners = [];
-      if (uid != null) {
-        this.uid = uid;
-      }
-    }
-
-    Operation.prototype.type = "Operation";
-
-    Operation.prototype.retrieveSub = function() {
-      throw new Error("sub properties are not enable on this operation type!");
-    };
-
-    Operation.prototype.observe = function(f) {
-      return this.event_listeners.push(f);
-    };
-
-    Operation.prototype.unobserve = function(f) {
-      return this.event_listeners = this.event_listeners.filter(function(g) {
-        return f !== g;
-      });
-    };
-
-    Operation.prototype.deleteAllObservers = function() {
-      return this.event_listeners = [];
-    };
-
-    Operation.prototype["delete"] = function() {
-      (new types.Delete(void 0, this)).execute();
-      return null;
-    };
-
-    Operation.prototype.callEvent = function() {
-      return this.forwardEvent.apply(this, [this].concat(__slice.call(arguments)));
-    };
-
-    Operation.prototype.forwardEvent = function() {
-      var args, f, op, _i, _len, _ref, _results;
-      op = arguments[0], args = 2 <= arguments.length ? __slice.call(arguments, 1) : [];
-      _ref = this.event_listeners;
-      _results = [];
-      for (_i = 0, _len = _ref.length; _i < _len; _i++) {
-        f = _ref[_i];
-        _results.push(f.call.apply(f, [op].concat(__slice.call(args))));
-      }
-      return _results;
-    };
-
-    Operation.prototype.isDeleted = function() {
-      return this.is_deleted;
-    };
-
-    Operation.prototype.applyDelete = function(garbagecollect) {
-      if (garbagecollect == null) {
-        garbagecollect = true;
-      }
-      if (!this.garbage_collected) {
-        this.is_deleted = true;
-        if (garbagecollect) {
-          this.garbage_collected = true;
-          return HB.addToGarbageCollector(this);
-        }
-      }
-    };
-
-    Operation.prototype.cleanup = function() {
-      HB.removeOperation(this);
-      return this.deleteAllObservers();
-    };
-
-    Operation.prototype.setParent = function(parent) {
-      this.parent = parent;
-    };
-
-    Operation.prototype.getParent = function() {
-      return this.parent;
-    };
-
-    Operation.prototype.getUid = function() {
-      if (this.uid.noOperation == null) {
-        return this.uid;
-      } else {
-        return this.uid.alt;
-      }
-    };
-
-    Operation.prototype.cloneUid = function() {
-      var n, uid, v, _ref;
-      uid = {};
-      _ref = this.getUid();
-      for (n in _ref) {
-        v = _ref[n];
-        uid[n] = v;
-      }
-      return uid;
-    };
-
-    Operation.prototype.dontSync = function() {
-      return this.uid.doSync = false;
-    };
-
-    Operation.prototype.execute = function() {
-      var l, _i, _len;
-      this.is_executed = true;
-      if (this.uid == null) {
-        this.uid = HB.getNextOperationIdentifier();
-      }
-      if (this.uid.noOperation == null) {
-        HB.addOperation(this);
-        for (_i = 0, _len = execution_listener.length; _i < _len; _i++) {
-          l = execution_listener[_i];
-          l(this._encode());
-        }
-      }
-      return this;
-    };
-
-    Operation.prototype.saveOperation = function(name, op) {
-      if ((op != null ? op.execute : void 0) != null) {
-        return this[name] = op;
-      } else if (op != null) {
-        if (this.unchecked == null) {
-          this.unchecked = {};
-        }
-        return this.unchecked[name] = op;
-      }
-    };
-
-    Operation.prototype.validateSavedOperations = function() {
-      var name, op, op_uid, success, uninstantiated, _ref;
-      uninstantiated = {};
-      success = this;
-      _ref = this.unchecked;
-      for (name in _ref) {
-        op_uid = _ref[name];
-        op = HB.getOperation(op_uid);
-        if (op) {
-          this[name] = op;
-        } else {
-          uninstantiated[name] = op_uid;
-          success = false;
-        }
-      }
-      delete this.unchecked;
-      if (!success) {
-        this.unchecked = uninstantiated;
-      }
-      return success;
-    };
-
-    return Operation;
-
-  })();
-  types.Delete = (function(_super) {
-    __extends(Delete, _super);
-
-    function Delete(uid, deletes) {
-      this.saveOperation('deletes', deletes);
-      Delete.__super__.constructor.call(this, uid);
-    }
-
-    Delete.prototype.type = "Delete";
-
-    Delete.prototype._encode = function() {
-      return {
-        'type': "Delete",
-        'uid': this.getUid(),
-        'deletes': this.deletes.getUid()
-      };
-    };
-
-    Delete.prototype.execute = function() {
-      var res;
-      if (this.validateSavedOperations()) {
-        res = Delete.__super__.execute.apply(this, arguments);
-        if (res) {
-          this.deletes.applyDelete(this);
-        }
-        return res;
-      } else {
-        return false;
-      }
-    };
-
-    return Delete;
-
-  })(types.Operation);
-  types.Delete.parse = function(o) {
-    var deletes_uid, uid;
-    uid = o['uid'], deletes_uid = o['deletes'];
-    return new this(uid, deletes_uid);
-  };
-  types.Insert = (function(_super) {
-    __extends(Insert, _super);
-
-    function Insert(uid, prev_cl, next_cl, origin, parent) {
-      this.saveOperation('parent', parent);
-      this.saveOperation('prev_cl', prev_cl);
-      this.saveOperation('next_cl', next_cl);
-      if (origin != null) {
-        this.saveOperation('origin', origin);
-      } else {
-        this.saveOperation('origin', prev_cl);
-      }
-      Insert.__super__.constructor.call(this, uid);
-    }
-
-    Insert.prototype.type = "Insert";
-
-    Insert.prototype.applyDelete = function(o) {
-      var callLater, garbagecollect, _ref;
-      if (this.deleted_by == null) {
-        this.deleted_by = [];
-      }
-      callLater = false;
-      if ((this.parent != null) && !this.isDeleted() && (o != null)) {
-        callLater = true;
-      }
-      if (o != null) {
-        this.deleted_by.push(o);
-      }
-      garbagecollect = false;
-      if (this.next_cl.isDeleted()) {
-        garbagecollect = true;
-      }
-      Insert.__super__.applyDelete.call(this, garbagecollect);
-      if (callLater) {
-        this.callOperationSpecificDeleteEvents(o);
-      }
-      if ((_ref = this.prev_cl) != null ? _ref.isDeleted() : void 0) {
-        return this.prev_cl.applyDelete();
-      }
-    };
-
-    Insert.prototype.cleanup = function() {
-      var d, o, _i, _len, _ref;
-      if (this.next_cl.isDeleted()) {
-        _ref = this.deleted_by;
-        for (_i = 0, _len = _ref.length; _i < _len; _i++) {
-          d = _ref[_i];
-          d.cleanup();
-        }
-        o = this.next_cl;
-        while (o.type !== "Delimiter") {
-          if (o.origin === this) {
-            o.origin = this.prev_cl;
-          }
-          o = o.next_cl;
-        }
-        this.prev_cl.next_cl = this.next_cl;
-        this.next_cl.prev_cl = this.prev_cl;
-        return Insert.__super__.cleanup.apply(this, arguments);
-      }
-    };
-
-    Insert.prototype.getDistanceToOrigin = function() {
-      var d, o;
-      d = 0;
-      o = this.prev_cl;
-      while (true) {
-        if (this.origin === o) {
-          break;
-        }
-        d++;
-        o = o.prev_cl;
-      }
-      return d;
-    };
-
-    Insert.prototype.execute = function() {
-      var distance_to_origin, i, o;
-      if (!this.validateSavedOperations()) {
-        return false;
-      } else {
-        if (this.parent != null) {
-          if (this.prev_cl == null) {
-            this.prev_cl = this.parent.beginning;
-          }
-          if (this.origin == null) {
-            this.origin = this.parent.beginning;
-          }
-          if (this.next_cl == null) {
-            this.next_cl = this.parent.end;
-          }
-        }
-        if (this.prev_cl != null) {
-          distance_to_origin = this.getDistanceToOrigin();
-          o = this.prev_cl.next_cl;
-          i = distance_to_origin;
-          while (true) {
-            if (o !== this.next_cl) {
-              if (o.getDistanceToOrigin() === i) {
-                if (o.uid.creator < this.uid.creator) {
-                  this.prev_cl = o;
-                  distance_to_origin = i + 1;
-                } else {
-
-                }
-              } else if (o.getDistanceToOrigin() < i) {
-                if (i - distance_to_origin <= o.getDistanceToOrigin()) {
-                  this.prev_cl = o;
-                  distance_to_origin = i + 1;
-                } else {
-
-                }
-              } else {
-                break;
-              }
-              i++;
-              o = o.next_cl;
-            } else {
-              break;
-            }
-          }
-          this.next_cl = this.prev_cl.next_cl;
-          this.prev_cl.next_cl = this;
-          this.next_cl.prev_cl = this;
-        }
-        this.setParent(this.prev_cl.getParent());
-        Insert.__super__.execute.apply(this, arguments);
-        this.callOperationSpecificInsertEvents();
-        return this;
-      }
-    };
-
-    Insert.prototype.callOperationSpecificInsertEvents = function() {
-      var _ref;
-      return (_ref = this.parent) != null ? _ref.callEvent([
-        {
-          type: "insert",
-          position: this.getPosition(),
-          object: this.parent,
-          changedBy: this.uid.creator,
-          value: this.content
-        }
-      ]) : void 0;
-    };
-
-    Insert.prototype.callOperationSpecificDeleteEvents = function(o) {
-      return this.parent.callEvent([
-        {
-          type: "delete",
-          position: this.getPosition(),
-          object: this.parent,
-          length: 1,
-          changedBy: o.uid.creator
-        }
-      ]);
-    };
-
-    Insert.prototype.getPosition = function() {
-      var position, prev;
-      position = 0;
-      prev = this.prev_cl;
-      while (true) {
-        if (prev instanceof types.Delimiter) {
-          break;
-        }
-        if (!prev.isDeleted()) {
-          position++;
-        }
-        prev = prev.prev_cl;
-      }
-      return position;
-    };
-
-    return Insert;
-
-  })(types.Operation);
-  types.ImmutableObject = (function(_super) {
-    __extends(ImmutableObject, _super);
-
-    function ImmutableObject(uid, content) {
-      this.content = content;
-      ImmutableObject.__super__.constructor.call(this, uid);
-    }
-
-    ImmutableObject.prototype.type = "ImmutableObject";
-
-    ImmutableObject.prototype.val = function() {
-      return this.content;
-    };
-
-    ImmutableObject.prototype._encode = function() {
-      var json;
-      json = {
-        'type': this.type,
-        'uid': this.getUid(),
-        'content': this.content
-      };
-      return json;
-    };
-
-    return ImmutableObject;
-
-  })(types.Operation);
-  types.ImmutableObject.parse = function(json) {
-    var content, uid;
-    uid = json['uid'], content = json['content'];
-    return new this(uid, content);
-  };
-  types.Delimiter = (function(_super) {
-    __extends(Delimiter, _super);
-
-    function Delimiter(prev_cl, next_cl, origin) {
-      this.saveOperation('prev_cl', prev_cl);
-      this.saveOperation('next_cl', next_cl);
-      this.saveOperation('origin', prev_cl);
-      Delimiter.__super__.constructor.call(this, {
-        noOperation: true
-      });
-    }
-
-    Delimiter.prototype.type = "Delimiter";
-
-    Delimiter.prototype.applyDelete = function() {
-      var o;
-      Delimiter.__super__.applyDelete.call(this);
-      o = this.prev_cl;
-      while (o != null) {
-        o.applyDelete();
-        o = o.prev_cl;
-      }
-      return void 0;
-    };
-
-    Delimiter.prototype.cleanup = function() {
-      return Delimiter.__super__.cleanup.call(this);
-    };
-
-    Delimiter.prototype.execute = function() {
-      var _ref, _ref1;
-      if (((_ref = this.unchecked) != null ? _ref['next_cl'] : void 0) != null) {
-        return Delimiter.__super__.execute.apply(this, arguments);
-      } else if ((_ref1 = this.unchecked) != null ? _ref1['prev_cl'] : void 0) {
-        if (this.validateSavedOperations()) {
-          if (this.prev_cl.next_cl != null) {
-            throw new Error("Probably duplicated operations");
-          }
-          this.prev_cl.next_cl = this;
-          return Delimiter.__super__.execute.apply(this, arguments);
-        } else {
-          return false;
-        }
-      } else if ((this.prev_cl != null) && (this.prev_cl.next_cl == null)) {
-        delete this.prev_cl.unchecked.next_cl;
-        this.prev_cl.next_cl = this;
-        return Delimiter.__super__.execute.apply(this, arguments);
-      } else if ((this.prev_cl != null) || (this.next_cl != null) || true) {
-        return Delimiter.__super__.execute.apply(this, arguments);
-      }
-    };
-
-    Delimiter.prototype._encode = function() {
-      var _ref, _ref1;
-      return {
-        'type': this.type,
-        'uid': this.getUid(),
-        'prev': (_ref = this.prev_cl) != null ? _ref.getUid() : void 0,
-        'next': (_ref1 = this.next_cl) != null ? _ref1.getUid() : void 0
-      };
-    };
-
-    return Delimiter;
-
-  })(types.Operation);
-  types.Delimiter.parse = function(json) {
-    var next, prev, uid;
-    uid = json['uid'], prev = json['prev'], next = json['next'];
-    return new this(uid, prev, next);
-  };
-  return {
-    'types': types,
-    'execution_listener': execution_listener
-  };
-};

build/node/Types/JsonTypes.js

@@ -1,158 +0,0 @@
-var text_types_uninitialized,
-  __hasProp = {}.hasOwnProperty,
-  __extends = function(child, parent) { for (var key in parent) { if (__hasProp.call(parent, key)) child[key] = parent[key]; } function ctor() { this.constructor = child; } ctor.prototype = parent.prototype; child.prototype = new ctor(); child.__super__ = parent.prototype; return child; };
-
-text_types_uninitialized = require("./TextTypes");
-
-module.exports = function(HB) {
-  var text_types, types;
-  text_types = text_types_uninitialized(HB);
-  types = text_types.types;
-  types.Object = (function(_super) {
-    __extends(Object, _super);
-
-    function Object() {
-      return Object.__super__.constructor.apply(this, arguments);
-    }
-
-    Object.prototype.type = "Object";
-
-    Object.prototype.applyDelete = function() {
-      return Object.__super__.applyDelete.call(this);
-    };
-
-    Object.prototype.cleanup = function() {
-      return Object.__super__.cleanup.call(this);
-    };
-
-    Object.prototype.toJson = function(transform_to_value) {
-      var json, name, o, that, val;
-      if (transform_to_value == null) {
-        transform_to_value = false;
-      }
-      if ((this.bound_json == null) || (Object.observe == null) || true) {
-        val = this.val();
-        json = {};
-        for (name in val) {
-          o = val[name];
-          if (o instanceof types.Object) {
-            json[name] = o.toJson(transform_to_value);
-          } else if (o instanceof types.Array) {
-            json[name] = o.toJson(transform_to_value);
-          } else if (transform_to_value && o instanceof types.Operation) {
-            json[name] = o.val();
-          } else {
-            json[name] = o;
-          }
-        }
-        this.bound_json = json;
-        if (Object.observe != null) {
-          that = this;
-          Object.observe(this.bound_json, function(events) {
-            var event, _i, _len, _results;
-            _results = [];
-            for (_i = 0, _len = events.length; _i < _len; _i++) {
-              event = events[_i];
-              if ((event.changedBy == null) && (event.type === "add" || (event.type = "update"))) {
-                _results.push(that.val(event.name, event.object[event.name]));
-              } else {
-                _results.push(void 0);
-              }
-            }
-            return _results;
-          });
-          this.observe(function(events) {
-            var event, notifier, oldVal, _i, _len, _results;
-            _results = [];
-            for (_i = 0, _len = events.length; _i < _len; _i++) {
-              event = events[_i];
-              if (event.created_ !== HB.getUserId()) {
-                notifier = Object.getNotifier(that.bound_json);
-                oldVal = that.bound_json[event.name];
-                if (oldVal != null) {
-                  notifier.performChange('update', function() {
-                    return that.bound_json[event.name] = that.val(event.name);
-                  }, that.bound_json);
-                  _results.push(notifier.notify({
-                    object: that.bound_json,
-                    type: 'update',
-                    name: event.name,
-                    oldValue: oldVal,
-                    changedBy: event.changedBy
-                  }));
-                } else {
-                  notifier.performChange('add', function() {
-                    return that.bound_json[event.name] = that.val(event.name);
-                  }, that.bound_json);
-                  _results.push(notifier.notify({
-                    object: that.bound_json,
-                    type: 'add',
-                    name: event.name,
-                    oldValue: oldVal,
-                    changedBy: event.changedBy
-                  }));
-                }
-              } else {
-                _results.push(void 0);
-              }
-            }
-            return _results;
-          });
-        }
-      }
-      return this.bound_json;
-    };
-
-    Object.prototype.val = function(name, content) {
-      var args, i, o, type, _i, _ref;
-      if ((name != null) && arguments.length > 1) {
-        if ((content != null) && (content.constructor != null)) {
-          type = types[content.constructor.name];
-          if ((type != null) && (type.create != null)) {
-            args = [];
-            for (i = _i = 1, _ref = arguments.length; 1 <= _ref ? _i < _ref : _i > _ref; i = 1 <= _ref ? ++_i : --_i) {
-              args.push(arguments[i]);
-            }
-            o = type.create.apply(null, args);
-            return Object.__super__.val.call(this, name, o);
-          } else {
-            throw new Error("The " + content.constructor.name + "-type is not (yet) supported in Y.");
-          }
-        } else {
-          return Object.__super__.val.call(this, name, content);
-        }
-      } else {
-        return Object.__super__.val.call(this, name);
-      }
-    };
-
-    Object.prototype._encode = function() {
-      return {
-        'type': this.type,
-        'uid': this.getUid()
-      };
-    };
-
-    return Object;
-
-  })(types.MapManager);
-  types.Object.parse = function(json) {
-    var uid;
-    uid = json['uid'];
-    return new this(uid);
-  };
-  types.Object.create = function(content, mutable) {
-    var json, n, o;
-    json = new types.Object().execute();
-    for (n in content) {
-      o = content[n];
-      json.val(n, o, mutable);
-    }
-    return json;
-  };
-  types.Number = {};
-  types.Number.create = function(content) {
-    return content;
-  };
-  return text_types;
-};

build/node/Types/StructuredTypes.js

@@ -1,354 +0,0 @@
-var basic_types_uninitialized,
-  __hasProp = {}.hasOwnProperty,
-  __extends = function(child, parent) { for (var key in parent) { if (__hasProp.call(parent, key)) child[key] = parent[key]; } function ctor() { this.constructor = child; } ctor.prototype = parent.prototype; child.prototype = new ctor(); child.__super__ = parent.prototype; return child; };
-
-basic_types_uninitialized = require("./BasicTypes");
-
-module.exports = function(HB) {
-  var basic_types, types;
-  basic_types = basic_types_uninitialized(HB);
-  types = basic_types.types;
-  types.MapManager = (function(_super) {
-    __extends(MapManager, _super);
-
-    function MapManager(uid) {
-      this.map = {};
-      MapManager.__super__.constructor.call(this, uid);
-    }
-
-    MapManager.prototype.type = "MapManager";
-
-    MapManager.prototype.applyDelete = function() {
-      var name, p, _ref;
-      _ref = this.map;
-      for (name in _ref) {
-        p = _ref[name];
-        p.applyDelete();
-      }
-      return MapManager.__super__.applyDelete.call(this);
-    };
-
-    MapManager.prototype.cleanup = function() {
-      return MapManager.__super__.cleanup.call(this);
-    };
-
-    MapManager.prototype.val = function(name, content) {
-      var o, prop, result, _ref;
-      if (arguments.length > 1) {
-        this.retrieveSub(name).replace(content);
-        return this;
-      } else if (name != null) {
-        prop = this.map[name];
-        if ((prop != null) && !prop.isContentDeleted()) {
-          return prop.val();
-        } else {
-          return void 0;
-        }
-      } else {
-        result = {};
-        _ref = this.map;
-        for (name in _ref) {
-          o = _ref[name];
-          if (!o.isContentDeleted()) {
-            result[name] = o.val();
-          }
-        }
-        return result;
-      }
-    };
-
-    MapManager.prototype["delete"] = function(name) {
-      var _ref;
-      if ((_ref = this.map[name]) != null) {
-        _ref.deleteContent();
-      }
-      return this;
-    };
-
-    MapManager.prototype.retrieveSub = function(property_name) {
-      var event_properties, event_this, map_uid, rm, rm_uid;
-      if (this.map[property_name] == null) {
-        event_properties = {
-          name: property_name
-        };
-        event_this = this;
-        map_uid = this.cloneUid();
-        map_uid.sub = property_name;
-        rm_uid = {
-          noOperation: true,
-          alt: map_uid
-        };
-        rm = new types.ReplaceManager(event_properties, event_this, rm_uid);
-        this.map[property_name] = rm;
-        rm.setParent(this, property_name);
-        rm.execute();
-      }
-      return this.map[property_name];
-    };
-
-    return MapManager;
-
-  })(types.Operation);
-  types.ListManager = (function(_super) {
-    __extends(ListManager, _super);
-
-    function ListManager(uid) {
-      this.beginning = new types.Delimiter(void 0, void 0);
-      this.end = new types.Delimiter(this.beginning, void 0);
-      this.beginning.next_cl = this.end;
-      this.beginning.execute();
-      this.end.execute();
-      ListManager.__super__.constructor.call(this, uid);
-    }
-
-    ListManager.prototype.type = "ListManager";
-
-    ListManager.prototype.execute = function() {
-      if (this.validateSavedOperations()) {
-        this.beginning.setParent(this);
-        this.end.setParent(this);
-        return ListManager.__super__.execute.apply(this, arguments);
-      } else {
-        return false;
-      }
-    };
-
-    ListManager.prototype.getLastOperation = function() {
-      return this.end.prev_cl;
-    };
-
-    ListManager.prototype.getFirstOperation = function() {
-      return this.beginning.next_cl;
-    };
-
-    ListManager.prototype.toArray = function() {
-      var o, result;
-      o = this.beginning.next_cl;
-      result = [];
-      while (o !== this.end) {
-        result.push(o);
-        o = o.next_cl;
-      }
-      return result;
-    };
-
-    ListManager.prototype.getOperationByPosition = function(position) {
-      var o;
-      o = this.beginning;
-      while (true) {
-        if (o instanceof types.Delimiter && (o.prev_cl != null)) {
-          o = o.prev_cl;
-          while (o.isDeleted() || !(o instanceof types.Delimiter)) {
-            o = o.prev_cl;
-          }
-          break;
-        }
-        if (position <= 0 && !o.isDeleted()) {
-          break;
-        }
-        o = o.next_cl;
-        if (!o.isDeleted()) {
-          position -= 1;
-        }
-      }
-      return o;
-    };
-
-    return ListManager;
-
-  })(types.Operation);
-  types.ReplaceManager = (function(_super) {
-    __extends(ReplaceManager, _super);
-
-    function ReplaceManager(event_properties, event_this, uid, beginning, end) {
-      this.event_properties = event_properties;
-      this.event_this = event_this;
-      if (this.event_properties['object'] == null) {
-        this.event_properties['object'] = this.event_this;
-      }
-      ReplaceManager.__super__.constructor.call(this, uid, beginning, end);
-    }
-
-    ReplaceManager.prototype.type = "ReplaceManager";
-
-    ReplaceManager.prototype.applyDelete = function() {
-      var o;
-      o = this.beginning;
-      while (o != null) {
-        o.applyDelete();
-        o = o.next_cl;
-      }
-      return ReplaceManager.__super__.applyDelete.call(this);
-    };
-
-    ReplaceManager.prototype.cleanup = function() {
-      return ReplaceManager.__super__.cleanup.call(this);
-    };
-
-    ReplaceManager.prototype.callEventDecorator = function(events) {
-      var event, name, prop, _i, _len, _ref;
-      if (!this.isDeleted()) {
-        for (_i = 0, _len = events.length; _i < _len; _i++) {
-          event = events[_i];
-          _ref = this.event_properties;
-          for (name in _ref) {
-            prop = _ref[name];
-            event[name] = prop;
-          }
-        }
-        this.event_this.callEvent(events);
-      }
-      return void 0;
-    };
-
-    ReplaceManager.prototype.replace = function(content, replaceable_uid) {
-      var o, relp;
-      o = this.getLastOperation();
-      relp = (new types.Replaceable(content, this, replaceable_uid, o, o.next_cl)).execute();
-      return void 0;
-    };
-
-    ReplaceManager.prototype.isContentDeleted = function() {
-      return this.getLastOperation().isDeleted();
-    };
-
-    ReplaceManager.prototype.deleteContent = function() {
-      (new types.Delete(void 0, this.getLastOperation().uid)).execute();
-      return void 0;
-    };
-
-    ReplaceManager.prototype.val = function() {
-      var o;
-      o = this.getLastOperation();
-      return typeof o.val === "function" ? o.val() : void 0;
-    };
-
-    ReplaceManager.prototype._encode = function() {
-      var json;
-      json = {
-        'type': this.type,
-        'uid': this.getUid(),
-        'beginning': this.beginning.getUid(),
-        'end': this.end.getUid()
-      };
-      return json;
-    };
-
-    return ReplaceManager;
-
-  })(types.ListManager);
-  types.Replaceable = (function(_super) {
-    __extends(Replaceable, _super);
-
-    function Replaceable(content, parent, uid, prev, next, origin, is_deleted) {
-      if ((content != null) && (content.creator != null)) {
-        this.saveOperation('content', content);
-      } else {
-        this.content = content;
-      }
-      this.saveOperation('parent', parent);
-      Replaceable.__super__.constructor.call(this, uid, prev, next, origin);
-      this.is_deleted = is_deleted;
-    }
-
-    Replaceable.prototype.type = "Replaceable";
-
-    Replaceable.prototype.val = function() {
-      return this.content;
-    };
-
-    Replaceable.prototype.applyDelete = function() {
-      var res, _base, _base1, _base2;
-      res = Replaceable.__super__.applyDelete.apply(this, arguments);
-      if (this.content != null) {
-        if (this.next_cl.type !== "Delimiter") {
-          if (typeof (_base = this.content).deleteAllObservers === "function") {
-            _base.deleteAllObservers();
-          }
-        }
-        if (typeof (_base1 = this.content).applyDelete === "function") {
-          _base1.applyDelete();
-        }
-        if (typeof (_base2 = this.content).dontSync === "function") {
-          _base2.dontSync();
-        }
-      }
-      this.content = null;
-      return res;
-    };
-
-    Replaceable.prototype.cleanup = function() {
-      return Replaceable.__super__.cleanup.apply(this, arguments);
-    };
-
-    Replaceable.prototype.callOperationSpecificInsertEvents = function() {
-      var old_value;
-      if (this.next_cl.type === "Delimiter" && this.prev_cl.type !== "Delimiter") {
-        if (!this.is_deleted) {
-          old_value = this.prev_cl.content;
-          this.parent.callEventDecorator([
-            {
-              type: "update",
-              changedBy: this.uid.creator,
-              oldValue: old_value
-            }
-          ]);
-        }
-        this.prev_cl.applyDelete();
-      } else if (this.next_cl.type !== "Delimiter") {
-        this.applyDelete();
-      } else {
-        this.parent.callEventDecorator([
-          {
-            type: "add",
-            changedBy: this.uid.creator
-          }
-        ]);
-      }
-      return void 0;
-    };
-
-    Replaceable.prototype.callOperationSpecificDeleteEvents = function(o) {
-      if (this.next_cl.type === "Delimiter") {
-        return this.parent.callEventDecorator([
-          {
-            type: "delete",
-            changedBy: o.uid.creator,
-            oldValue: this.content
-          }
-        ]);
-      }
-    };
-
-    Replaceable.prototype._encode = function() {
-      var json;
-      json = {
-        'type': this.type,
-        'parent': this.parent.getUid(),
-        'prev': this.prev_cl.getUid(),
-        'next': this.next_cl.getUid(),
-        'origin': this.origin.getUid(),
-        'uid': this.getUid(),
-        'is_deleted': this.is_deleted
-      };
-      if (this.content instanceof types.Operation) {
-        json['content'] = this.content.getUid();
-      } else {
-        if ((this.content != null) && (this.content.creator != null)) {
-          throw new Error("You must not set creator here!");
-        }
-        json['content'] = this.content;
-      }
-      return json;
-    };
-
-    return Replaceable;
-
-  })(types.Insert);
-  types.Replaceable.parse = function(json) {
-    var content, is_deleted, next, origin, parent, prev, uid;
-    content = json['content'], parent = json['parent'], uid = json['uid'], prev = json['prev'], next = json['next'], origin = json['origin'], is_deleted = json['is_deleted'];
-    return new this(content, parent, uid, prev, next, origin, is_deleted);
-  };
-  return basic_types;
-};

build/node/Types/TextTypes.js

@@ -1,558 +0,0 @@
-var structured_types_uninitialized,
-  __hasProp = {}.hasOwnProperty,
-  __extends = function(child, parent) { for (var key in parent) { if (__hasProp.call(parent, key)) child[key] = parent[key]; } function ctor() { this.constructor = child; } ctor.prototype = parent.prototype; child.prototype = new ctor(); child.__super__ = parent.prototype; return child; };
-
-structured_types_uninitialized = require("./StructuredTypes");
-
-module.exports = function(HB) {
-  var parser, structured_types, types;
-  structured_types = structured_types_uninitialized(HB);
-  types = structured_types.types;
-  parser = structured_types.parser;
-  types.TextInsert = (function(_super) {
-    __extends(TextInsert, _super);
-
-    function TextInsert(content, uid, prev, next, origin, parent) {
-      if (content != null ? content.creator : void 0) {
-        this.saveOperation('content', content);
-      } else {
-        this.content = content;
-      }
-      TextInsert.__super__.constructor.call(this, uid, prev, next, origin, parent);
-    }
-
-    TextInsert.prototype.type = "TextInsert";
-
-    TextInsert.prototype.getLength = function() {
-      if (this.isDeleted()) {
-        return 0;
-      } else {
-        return this.content.length;
-      }
-    };
-
-    TextInsert.prototype.applyDelete = function() {
-      TextInsert.__super__.applyDelete.apply(this, arguments);
-      if (this.content instanceof types.Operation) {
-        this.content.applyDelete();
-      }
-      return this.content = null;
-    };
-
-    TextInsert.prototype.execute = function() {
-      if (!this.validateSavedOperations()) {
-        return false;
-      } else {
-        if (this.content instanceof types.Operation) {
-          this.content.insert_parent = this;
-        }
-        return TextInsert.__super__.execute.call(this);
-      }
-    };
-
-    TextInsert.prototype.val = function(current_position) {
-      if (this.isDeleted() || (this.content == null)) {
-        return "";
-      } else {
-        return this.content;
-      }
-    };
-
-    TextInsert.prototype._encode = function() {
-      var json, _ref;
-      json = {
-        'type': this.type,
-        'uid': this.getUid(),
-        'prev': this.prev_cl.getUid(),
-        'next': this.next_cl.getUid(),
-        'origin': this.origin.getUid(),
-        'parent': this.parent.getUid()
-      };
-      if (((_ref = this.content) != null ? _ref.getUid : void 0) != null) {
-        json['content'] = this.content.getUid();
-      } else {
-        json['content'] = this.content;
-      }
-      return json;
-    };
-
-    return TextInsert;
-
-  })(types.Insert);
-  types.TextInsert.parse = function(json) {
-    var content, next, origin, parent, prev, uid;
-    content = json['content'], uid = json['uid'], prev = json['prev'], next = json['next'], origin = json['origin'], parent = json['parent'];
-    return new types.TextInsert(content, uid, prev, next, origin, parent);
-  };
-  types.Array = (function(_super) {
-    __extends(Array, _super);
-
-    function Array() {
-      return Array.__super__.constructor.apply(this, arguments);
-    }
-
-    Array.prototype.type = "Array";
-
-    Array.prototype.applyDelete = function() {
-      var o;
-      o = this.end;
-      while (o != null) {
-        o.applyDelete();
-        o = o.prev_cl;
-      }
-      return Array.__super__.applyDelete.call(this);
-    };
-
-    Array.prototype.cleanup = function() {
-      return Array.__super__.cleanup.call(this);
-    };
-
-    Array.prototype.toJson = function(transform_to_value) {
-      var i, o, val, _i, _len, _results;
-      if (transform_to_value == null) {
-        transform_to_value = false;
-      }
-      val = this.val();
-      _results = [];
-      for (o = _i = 0, _len = val.length; _i < _len; o = ++_i) {
-        i = val[o];
-        if (o instanceof types.Object) {
-          _results.push(o.toJson(transform_to_value));
-        } else if (o instanceof types.Array) {
-          _results.push(o.toJson(transform_to_value));
-        } else if (transform_to_value && o instanceof types.Operation) {
-          _results.push(o.val());
-        } else {
-          _results.push(o);
-        }
-      }
-      return _results;
-    };
-
-    Array.prototype.val = function(pos) {
-      var o, result;
-      if (pos != null) {
-        o = this.getOperationByPosition(pos + 1);
-        if (!(o instanceof types.Delimiter)) {
-          return o.val();
-        } else {
-          throw new Error("this position does not exist");
-        }
-      } else {
-        o = this.beginning.next_cl;
-        result = [];
-        while (o !== this.end) {
-          if (!o.isDeleted()) {
-            result.push(o.val());
-          }
-          o = o.next_cl;
-        }
-        return result;
-      }
-    };
-
-    Array.prototype.push = function(content) {
-      return this.insertAfter(this.end.prev_cl, content);
-    };
-
-    Array.prototype.insertAfter = function(left, content, options) {
-      var c, createContent, right, tmp, _i, _len;
-      createContent = function(content, options) {
-        var type;
-        if ((content != null) && (content.constructor != null)) {
-          type = types[content.constructor.name];
-          if ((type != null) && (type.create != null)) {
-            return type.create(content, options);
-          } else {
-            throw new Error("The " + content.constructor.name + "-type is not (yet) supported in Y.");
-          }
-        } else {
-          return content;
-        }
-      };
-      right = left.next_cl;
-      while (right.isDeleted()) {
-        right = right.next_cl;
-      }
-      left = right.prev_cl;
-      if (content instanceof types.Operation) {
-        (new types.TextInsert(content, void 0, left, right)).execute();
-      } else {
-        for (_i = 0, _len = content.length; _i < _len; _i++) {
-          c = content[_i];
-          tmp = (new types.TextInsert(createContent(c, options), void 0, left, right)).execute();
-          left = tmp;
-        }
-      }
-      return this;
-    };
-
-    Array.prototype.insert = function(position, content, options) {
-      var ith;
-      ith = this.getOperationByPosition(position);
-      return this.insertAfter(ith, [content], options);
-    };
-
-    Array.prototype["delete"] = function(position, length) {
-      var d, delete_ops, i, o, _i;
-      o = this.getOperationByPosition(position + 1);
-      delete_ops = [];
-      for (i = _i = 0; 0 <= length ? _i < length : _i > length; i = 0 <= length ? ++_i : --_i) {
-        if (o instanceof types.Delimiter) {
-          break;
-        }
-        d = (new types.Delete(void 0, o)).execute();
-        o = o.next_cl;
-        while ((!(o instanceof types.Delimiter)) && o.isDeleted()) {
-          o = o.next_cl;
-        }
-        delete_ops.push(d._encode());
-      }
-      return this;
-    };
-
-    Array.prototype._encode = function() {
-      var json;
-      json = {
-        'type': this.type,
-        'uid': this.getUid()
-      };
-      return json;
-    };
-
-    return Array;
-
-  })(types.ListManager);
-  types.Array.parse = function(json) {
-    var uid;
-    uid = json['uid'];
-    return new this(uid);
-  };
-  types.Array.create = function(content, mutable) {
-    var ith, list;
-    if (mutable === "mutable") {
-      list = new types.Array().execute();
-      ith = list.getOperationByPosition(0);
-      list.insertAfter(ith, content);
-      return list;
-    } else if ((mutable == null) || (mutable === "immutable")) {
-      return content;
-    } else {
-      throw new Error("Specify either \"mutable\" or \"immutable\"!!");
-    }
-  };
-  types.String = (function(_super) {
-    __extends(String, _super);
-
-    function String(uid) {
-      this.textfields = [];
-      String.__super__.constructor.call(this, uid);
-    }
-
-    String.prototype.type = "String";
-
-    String.prototype.val = function() {
-      var c, o;
-      c = (function() {
-        var _i, _len, _ref, _results;
-        _ref = this.toArray();
-        _results = [];
-        for (_i = 0, _len = _ref.length; _i < _len; _i++) {
-          o = _ref[_i];
-          if (o.val != null) {
-            _results.push(o.val());
-          } else {
-            _results.push("");
-          }
-        }
-        return _results;
-      }).call(this);
-      return c.join('');
-    };
-
-    String.prototype.toString = function() {
-      return this.val();
-    };
-
-    String.prototype.insert = function(position, content, options) {
-      var ith;
-      ith = this.getOperationByPosition(position);
-      return this.insertAfter(ith, content, options);
-    };
-
-    String.prototype.bind = function(textfield, dom_root) {
-      var createRange, creator_token, t, word, writeContent, writeRange, _i, _len, _ref;
-      if (dom_root == null) {
-        dom_root = window;
-      }
-      if (dom_root.getSelection == null) {
-        dom_root = window;
-      }
-      _ref = this.textfields;
-      for (_i = 0, _len = _ref.length; _i < _len; _i++) {
-        t = _ref[_i];
-        if (t === textfield) {
-          return;
-        }
-      }
-      creator_token = false;
-      word = this;
-      textfield.value = this.val();
-      this.textfields.push(textfield);
-      if ((textfield.selectionStart != null) && (textfield.setSelectionRange != null)) {
-        createRange = function(fix) {
-          var left, right;
-          left = textfield.selectionStart;
-          right = textfield.selectionEnd;
-          if (fix != null) {
-            left = fix(left);
-            right = fix(right);
-          }
-          return {
-            left: left,
-            right: right
-          };
-        };
-        writeRange = function(range) {
-          writeContent(word.val());
-          return textfield.setSelectionRange(range.left, range.right);
-        };
-        writeContent = function(content) {
-          return textfield.value = content;
-        };
-      } else {
-        createRange = function(fix) {
-          var clength, left, right, s;
-          s = dom_root.getSelection();
-          clength = textfield.textContent.length;
-          left = Math.min(s.anchorOffset, clength);
-          right = Math.min(s.focusOffset, clength);
-          if (fix != null) {
-            left = fix(left);
-            right = fix(right);
-          }
-          return {
-            left: left,
-            right: right,
-            isReal: true
-          };
-        };
-        writeRange = function(range) {
-          var r, s, textnode;
-          writeContent(word.val());
-          textnode = textfield.childNodes[0];
-          if (range.isReal && (textnode != null)) {
-            if (range.left < 0) {
-              range.left = 0;
-            }
-            range.right = Math.max(range.left, range.right);
-            if (range.right > textnode.length) {
-              range.right = textnode.length;
-            }
-            range.left = Math.min(range.left, range.right);
-            r = document.createRange();
-            r.setStart(textnode, range.left);
-            r.setEnd(textnode, range.right);
-            s = window.getSelection();
-            s.removeAllRanges();
-            return s.addRange(r);
-          }
-        };
-        writeContent = function(content) {
-          var append;
-          append = "";
-          if (content[content.length - 1] === " ") {
-            content = content.slice(0, content.length - 1);
-            append = '&nbsp;';
-          }
-          textfield.textContent = content;
-          return textfield.innerHTML += append;
-        };
-      }
-      writeContent(this.val());
-      this.observe(function(events) {
-        var event, fix, o_pos, r, _j, _len1, _results;
-        _results = [];
-        for (_j = 0, _len1 = events.length; _j < _len1; _j++) {
-          event = events[_j];
-          if (!creator_token) {
-            if (event.type === "insert") {
-              o_pos = event.position;
-              fix = function(cursor) {
-                if (cursor <= o_pos) {
-                  return cursor;
-                } else {
-                  cursor += 1;
-                  return cursor;
-                }
-              };
-              r = createRange(fix);
-              _results.push(writeRange(r));
-            } else if (event.type === "delete") {
-              o_pos = event.position;
-              fix = function(cursor) {
-                if (cursor < o_pos) {
-                  return cursor;
-                } else {
-                  cursor -= 1;
-                  return cursor;
-                }
-              };
-              r = createRange(fix);
-              _results.push(writeRange(r));
-            } else {
-              _results.push(void 0);
-            }
-          } else {
-            _results.push(void 0);
-          }
-        }
-        return _results;
-      });
-      textfield.onkeypress = function(event) {
-        var char, diff, pos, r;
-        if (word.is_deleted) {
-          textfield.onkeypress = null;
-          return true;
-        }
-        creator_token = true;
-        char = null;
-        if (event.key != null) {
-          if (event.charCode === 32) {
-            char = " ";
-          } else if (event.keyCode === 13) {
-            char = '\n';
-          } else {
-            char = event.key;
-          }
-        } else {
-          char = window.String.fromCharCode(event.keyCode);
-        }
-        if (char.length > 1) {
-          return true;
-        } else if (char.length > 0) {
-          r = createRange();
-          pos = Math.min(r.left, r.right);
-          diff = Math.abs(r.right - r.left);
-          word["delete"](pos, diff);
-          word.insert(pos, char);
-          r.left = pos + char.length;
-          r.right = r.left;
-          writeRange(r);
-        }
-        event.preventDefault();
-        creator_token = false;
-        return false;
-      };
-      textfield.onpaste = function(event) {
-        if (word.is_deleted) {
-          textfield.onpaste = null;
-          return true;
-        }
-        return event.preventDefault();
-      };
-      textfield.oncut = function(event) {
-        if (word.is_deleted) {
-          textfield.oncut = null;
-          return true;
-        }
-        return event.preventDefault();
-      };
-      return textfield.onkeydown = function(event) {
-        var del_length, diff, new_pos, pos, r, val;
-        creator_token = true;
-        if (word.is_deleted) {
-          textfield.onkeydown = null;
-          return true;
-        }
-        r = createRange();
-        pos = Math.min(r.left, r.right, word.val().length);
-        diff = Math.abs(r.left - r.right);
-        if ((event.keyCode != null) && event.keyCode === 8) {
-          if (diff > 0) {
-            word["delete"](pos, diff);
-            r.left = pos;
-            r.right = pos;
-            writeRange(r);
-          } else {
-            if ((event.ctrlKey != null) && event.ctrlKey) {
-              val = word.val();
-              new_pos = pos;
-              del_length = 0;
-              if (pos > 0) {
-                new_pos--;
-                del_length++;
-              }
-              while (new_pos > 0 && val[new_pos] !== " " && val[new_pos] !== '\n') {
-                new_pos--;
-                del_length++;
-              }
-              word["delete"](new_pos, pos - new_pos);
-              r.left = new_pos;
-              r.right = new_pos;
-              writeRange(r);
-            } else {
-              if (pos > 0) {
-                word["delete"](pos - 1, 1);
-                r.left = pos - 1;
-                r.right = pos - 1;
-                writeRange(r);
-              }
-            }
-          }
-          event.preventDefault();
-          creator_token = false;
-          return false;
-        } else if ((event.keyCode != null) && event.keyCode === 46) {
-          if (diff > 0) {
-            word["delete"](pos, diff);
-            r.left = pos;
-            r.right = pos;
-            writeRange(r);
-          } else {
-            word["delete"](pos, 1);
-            r.left = pos;
-            r.right = pos;
-            writeRange(r);
-          }
-          event.preventDefault();
-          creator_token = false;
-          return false;
-        } else {
-          creator_token = false;
-          return true;
-        }
-      };
-    };
-
-    String.prototype._encode = function() {
-      var json;
-      json = {
-        'type': this.type,
-        'uid': this.getUid()
-      };
-      return json;
-    };
-
-    return String;
-
-  })(types.Array);
-  types.String.parse = function(json) {
-    var uid;
-    uid = json['uid'];
-    return new this(uid);
-  };
-  types.String.create = function(content, mutable) {
-    var word;
-    if (mutable === "mutable") {
-      word = new types.String().execute();
-      word.insert(0, content);
-      return word;
-    } else if ((mutable == null) || (mutable === "immutable")) {
-      return content;
-    } else {
-      throw new Error("Specify either \"mutable\" or \"immutable\"!!");
-    }
-  };
-  return structured_types;
-};

build/test/index.html

@@ -1,27 +0,0 @@
-<html>
-<head>
-  <meta charset="utf-8">
-  <title>Test Yatta!</title>
-    <link rel="stylesheet" href="../../node_modules/mocha/mocha.css" />
-</head>
-<body>
-  <div id="mocha"></div>
-  <div id="test_dom" test_attribute="the test" class="stuffy" style="color: blue"><p id="replaceme">replace me</p><p id="removeme">remove me</p><p>This is a test object for <b>XmlFramework</b></p><span class="span_element"><p>span</p></span></div>
-  <script src="../../node_modules/mocha/mocha.js" class="awesome"></script>
-  <script>
-    mocha.setup('bdd');
-    mocha.ui('bdd');
-    mocha.reporter('html');
-  </script>
-  <script src="TextYatta_test.js"></script>
-  <script src="JsonYatta_test.js"></script>
-  <!--script src="XmlYatta_test_browser.js"></script-->
-  <script>
-    //mocha.checkLeaks();
-    //mocha.run();
-    window.onerror = null;
-    if (window.mochaPhantomJS) { mochaPhantomJS.run(); }
-    else { mocha.run(); }
-  </script>
-</body>
-</html>

examples/README.md

@@ -1,5 +0,0 @@
-# Examples
-
-Here you find some (hopefully) usefull examples on how to use Yatta!
-
-Please note, that the XMPP Connector is the best supported Connector at the moment.

examples/XMPP-Polymer/index.html

@@ -1,15 +0,0 @@
-<!DOCTYPE HTML>
-<html>
-  <head>
-    <meta charset=utf-8 />
-    <title>Y Example</title>
-    <script src="../../../webcomponentsjs/webcomponents.min.js"></script>
-    <link rel="import" href="../../../polymer/polymer.html">
-
-    <link rel="import" href="y-test.html">
-  </head>
-  <body>
-    <y-test></y-test>
-    <script src="./index.js"></script>
-  </body>
-</html>

examples/XMPP-Polymer/index.js

@@ -1,19 +0,0 @@
-
-setTimeout(function(){
-  window.y_test = document.querySelector("y-test");
-
-  window.y_test.y.val("stuff",{otherstuff:{nostuff:"this is no stuff"}})
-  setTimeout(function(){
-    var res = y_test.y.val("stuff");
-    if(!(y_test.nostuff === "this is no stuff")){
-      console.log("Deep inherit doesn't work!")
-    }
-    window.y_stuff_property.val = {nostuff: "this is also no stuff"};
-    setTimeout(function(){
-      if(!(y_test.nostuff === "this is also no stuff")){
-        console.log("Element val overwrite doesn't work")
-      }
-      console.log("Everything is fine :)");
-    },500)
-  },500);
-},3000)

examples/XMPP/index.html

@@ -1,20 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-        <meta charset=utf-8 />
-        <title>Y Example</title>
-        <script src="../../build/browser/y.js"></script>
-        <script src="../../../y-connectors/y-xmpp/y-xmpp.js"></script>
-        <script src="./index.js"></script>
-</head>
-<body>
-<h1 contentEditable> yjs Tutorial</h1>
-<p> Collaborative Json editing with <a href="https://github.com/rwth-acis/yjs/">yjs</a>
-and XMPP Connector. </p>
-
-<textarea style="width:80%;" rows=40 id="textfield"></textarea>
-
-<p> <a href="https://github.com/rwth-acis/yjs/">yjs</a> is a Framework for Real-Time collaboration on arbitrary data types.
-</p>
-</body>
-</html>

examples/XMPP/index.js

@@ -1,26 +0,0 @@
-
-
-connector = new Y.XMPP("testy-xmpp-json2");
-connector.debug = true
-
-y = new Y(connector);
-
-window.onload = function(){
-  var textbox = document.getElementById("textfield");
-  y.observe(function(events){
-    for(var i=0; i<events.length; i++){
-      var event = events[i];
-      if(event.name === "textfield" && event.type !== "delete"){
-        y.val("textfield").bind(textbox);
-        y.val("headline").bind(document.querySelector("h1"))
-      }
-    }
-  });
-  connector.whenSynced(function(){
-    if(y.val("textfield") == null){
-      y.val("headline","headline", "mutable");
-      y.val("textfield","stuff", "mutable")
-    }
-  })
-
-};

gulpfile.coffee

@@ -1,122 +0,0 @@
-gulp = require('gulp')
-coffee = require('gulp-coffee')
-concat = require('gulp-concat')
-uglify = require 'gulp-uglify'
-sourcemaps = require('gulp-sourcemaps')
-browserify = require('gulp-browserify')
-rename = require 'gulp-rename'
-rimraf = require 'gulp-rimraf'
-gulpif = require 'gulp-if'
-ignore = require 'gulp-ignore'
-git = require 'gulp-git'
-debug = require 'gulp-debug'
-coffeelint = require 'gulp-coffeelint'
-mocha = require 'gulp-mocha'
-run = require 'gulp-run'
-ljs = require 'gulp-ljs'
-plumber = require 'gulp-plumber'
-mochaPhantomJS = require 'gulp-mocha-phantomjs'
-cache = require 'gulp-cached'
-coffeeify = require 'gulp-coffeeify'
-
-gulp.task 'default', ['build_browser']
-
-files =
-  lib : ['./lib/**/*.coffee']
-  browser : ['./lib/y.coffee','./lib/y-object.coffee']
-  #test : ['./test/**/*_test.coffee']
-  test : ['./test/Json_test.coffee', './test/Text_test.coffee']
-  gulp : ['./gulpfile.coffee']
-  examples : ['./examples/**/*.js']
-  other: ['./lib/**/*']
-
-files.all = []
-for name,file_list of files
-  if name isnt 'build'
-    files.all = files.all.concat file_list
-
-gulp.task 'deploy_nodejs', ->
-  gulp.src files.lib
-    .pipe sourcemaps.init()
-    .pipe coffee()
-    .pipe sourcemaps.write './'
-    .pipe gulp.dest 'build/node/'
-    .pipe gulpif '!**/', git.add({args : "-A"})
-
-gulp.task 'deploy', ['mocha', 'build_browser', 'deploy_nodejs', 'lint', 'phantom_test', 'codo']
-
-gulp.task 'build_browser', ->
-  gulp.src files.browser, { read: false }
-    .pipe plumber()
-    .pipe browserify
-      transform: ['coffeeify']
-      extensions: ['.coffee']
-      debug : true
-    .pipe rename
-      extname: ".js"
-    .pipe gulp.dest './build/browser/'
-    .pipe uglify()
-    .pipe gulp.dest '.'
-
-  gulp.src files.test, {read: false}
-    .pipe plumber()
-    .pipe browserify
-      transform: ['coffeeify']
-      extensions: ['.coffee']
-      debug: true
-    .pipe rename
-      extname: ".js"
-    .pipe gulp.dest './build/test/'
-
-gulp.task 'build_node', ->
-  gulp.src files.lib
-    .pipe plumber()
-    .pipe coffee({bare:true})
-    .pipe gulp.dest './build/node'
-
-gulp.task 'build', ['build_node', 'build_browser'], ->
-
-gulp.task 'watch', ['build_browser'], ->
-  gulp.watch files.all, ['build_browser']
-
-gulp.task 'mocha', ->
-  gulp.src files.test, { read: false }
-    .pipe plumber()
-    .pipe mocha {reporter : 'list'}
-
-
-gulp.task 'lint', ->
-  gulp.src files.all
-    .pipe ignore.include '**/*.coffee'
-    .pipe coffeelint {
-      "max_line_length":
-        "level": "ignore"
-      }
-    .pipe coffeelint.reporter()
-
-gulp.task 'phantom_watch', ['phantom_test'], ->
-  gulp.watch files.all, ['phantom_test']
-
-gulp.task 'literate', ->
-  gulp.src files.examples
-    .pipe ljs { code : true }
-    .pipe rename
-      basename : "README"
-      extname : ".md"
-    .pipe gulp.dest 'examples/'
-    .pipe gulpif '!**/', git.add({args : "-A"})
-
-gulp.task 'codo', [], ()->
-  command = './node_modules/codo/bin/codo -o "./doc" --name "yjs" --readme "README.md" --undocumented false --private true --title "yjs API" ./lib - LICENSE.txt '
-  run(command).exec()
-
-gulp.task 'phantom_test', ['build_browser'], ()->
-  gulp.src 'build/test/index.html'
-    .pipe mochaPhantomJS()
-
-gulp.task 'clean', ->
-  gulp.src ['./build/{browser,test,node}/**/*.{js,map}','./doc/'], { read: false }
-    .pipe rimraf()
-
-gulp.task 'default', ['clean','build'], ->
-

lib/ConnectorAdapter.coffee

@@ -1,56 +0,0 @@
-
-
-#
-# @param {Engine} engine The transformation engine
-# @param {HistoryBuffer} HB
-# @param {Array<Function>} execution_listener You must ensure that whenever an operation is executed, every function in this Array is called.
-#
-adaptConnector = (connector, engine, HB, execution_listener)->
-  send_ = (o)->
-    if o.uid.creator is HB.getUserId() and (typeof o.uid.op_number isnt "string")
-      connector.broadcast o
-
-  if connector.invokeSync?
-    HB.setInvokeSyncHandler connector.invokeSync
-
-  execution_listener.push send_
-  # For the XMPPConnector: lets send it as an array
-  # therefore, we have to restructure it later
-  encode_state_vector = (v)->
-    for name,value of v
-      user: name
-      state: value
-  parse_state_vector = (v)->
-    state_vector = {}
-    for s in v
-      state_vector[s.user] = s.state
-    state_vector
-
-  getStateVector = ()->
-    encode_state_vector HB.getOperationCounter()
-
-  getHB = (v)->
-    state_vector = parse_state_vector v
-    hb = HB._encode state_vector
-    for o in hb
-      o.fromHB = "true" # execute immediately
-    json =
-      hb: hb
-      state_vector: encode_state_vector HB.getOperationCounter()
-    json
-
-  applyHB = (hb)->
-    engine.applyOp hb
-
-  connector.getStateVector = getStateVector
-  connector.getHB = getHB
-  connector.applyHB = applyHB
-
-  connector.whenReceiving (sender, op)->
-    if op.uid.creator isnt HB.getUserId()
-      engine.applyOp op
-
-  if connector._whenBoundToY?
-    connector._whenBoundToY()
-
-module.exports = adaptConnector

lib/Engine.coffee

@@ -1,112 +0,0 @@
-
-window?.unprocessed_counter = 0 # del this
-window?.unprocessed_exec_counter = 0 # TODO
-window?.unprocessed_types = []
-
-#
-# @nodoc
-# The Engine handles how and in which order to execute operations and add operations to the HistoryBuffer.
-#
-class Engine
-
-  #
-  # @param {HistoryBuffer} HB
-  # @param {Object} types list of available types
-  #
-  constructor: (@HB, @types)->
-    @unprocessed_ops = []
-
-  #
-  # Parses an operatio from the json format. It uses the specified parser in your OperationType module.
-  #
-  parseOperation: (json)->
-    type = @types[json.type]
-    if type?.parse?
-      type.parse json
-    else
-      throw new Error "You forgot to specify a parser for type #{json.type}. The message is #{JSON.stringify json}."
-
-
-  #
-  # Apply a set of operations. E.g. the operations you received from another users HB._encode().
-  # @note You must not use this method when you already have ops in your HB!
-  ###
-  applyOpsBundle: (ops_json)->
-    ops = []
-    for o in ops_json
-      ops.push @parseOperation o
-    for o in ops
-      if not o.execute()
-        @unprocessed_ops.push o
-    @tryUnprocessed()
-  ###
-
-  #
-  # Same as applyOps but operations that are already in the HB are not applied.
-  # @see Engine.applyOps
-  #
-  applyOpsCheckDouble: (ops_json)->
-    for o in ops_json
-      if not @HB.getOperation(o.uid)?
-        @applyOp o
-
-  #
-  # Apply a set of operations. (Helper for using applyOp on Arrays)
-  # @see Engine.applyOp
-  applyOps: (ops_json)->
-    @applyOp ops_json
-
-  #
-  # Apply an operation that you received from another peer.
-  # TODO: make this more efficient!!
-  # - operations may only executed in order by creator, order them in object of arrays (key by creator)
-  # - you can probably make something like dependencies (creator1 waits for creator2)
-  applyOp: (op_json_array)->
-    if op_json_array.constructor isnt Array
-      op_json_array = [op_json_array]
-    for op_json in op_json_array
-      # $parse_and_execute will return false if $o_json was parsed and executed, otherwise the parsed operadion
-      o = @parseOperation op_json
-      if op_json.fromHB?
-        o.fromHB = op_json.fromHB
-      # @HB.addOperation o
-      if @HB.getOperation(o)?
-        # nop
-      else if ((not @HB.isExpectedOperation(o)) and (not o.fromHB?)) or (not o.execute())
-        @unprocessed_ops.push o
-        window?.unprocessed_types.push o.type # TODO: delete this
-    @tryUnprocessed()
-
-  #
-  # Call this method when you applied a new operation.
-  # It checks if operations that were previously not executable are now executable.
-  #
-  tryUnprocessed: ()->
-    while true
-      old_length = @unprocessed_ops.length
-      unprocessed = []
-      for op in @unprocessed_ops
-        if @HB.getOperation(op)?
-          # nop
-        else if (not @HB.isExpectedOperation(op) and (not op.fromHB?)) or (not op.execute())
-          unprocessed.push op
-      @unprocessed_ops = unprocessed
-      if @unprocessed_ops.length is old_length
-        break
-    if @unprocessed_ops.length isnt 0
-      @HB.invokeSync()
-
-
-module.exports = Engine
-
-
-
-
-
-
-
-
-
-
-
-

lib/HistoryBuffer.coffee

@@ -1,220 +0,0 @@
-
-#
-# @nodoc
-# An object that holds all applied operations.
-#
-# @note The HistoryBuffer is commonly abbreviated to HB.
-#
-class HistoryBuffer
-
-  #
-  # Creates an empty HB.
-  # @param {Object} user_id Creator of the HB.
-  #
-  constructor: (@user_id)->
-    @operation_counter = {}
-    @buffer = {}
-    @change_listeners = []
-    @garbage = [] # Will be cleaned on next call of garbageCollector
-    @trash = [] # Is deleted. Wait until it is not used anymore.
-    @performGarbageCollection = true
-    @garbageCollectTimeout = 30000
-    @reserved_identifier_counter = 0
-    setTimeout @emptyGarbage, @garbageCollectTimeout
-
-  resetUserId: (id)->
-    own = @buffer[@user_id]
-    if own?
-      for o_name,o of own
-        o.uid.creator = id
-      if @buffer[id]?
-        throw new Error "You are re-assigning an old user id - this is not (yet) possible!"
-      @buffer[id] = own
-      delete @buffer[@user_id]
-
-    @operation_counter[id] = @operation_counter[@user_id]
-    delete @operation_counter[@user_id]
-    @user_id = id
-
-  emptyGarbage: ()=>
-    for o in @garbage
-      #if @getOperationCounter(o.uid.creator) > o.uid.op_number
-      o.cleanup?()
-
-    @garbage = @trash
-    @trash = []
-    if @garbageCollectTimeout isnt -1
-      @garbageCollectTimeoutId = setTimeout @emptyGarbage, @garbageCollectTimeout
-    undefined
-
-  #
-  # Get the user id with wich the History Buffer was initialized.
-  #
-  getUserId: ()->
-    @user_id
-
-  addToGarbageCollector: ()->
-    if @performGarbageCollection
-      for o in arguments
-        if o?
-          @garbage.push o
-
-  stopGarbageCollection: ()->
-    @performGarbageCollection = false
-    @setManualGarbageCollect()
-    @garbage = []
-    @trash = []
-
-  setManualGarbageCollect: ()->
-    @garbageCollectTimeout = -1
-    clearTimeout @garbageCollectTimeoutId
-    @garbageCollectTimeoutId = undefined
-
-  setGarbageCollectTimeout: (@garbageCollectTimeout)->
-
-  #
-  # I propose to use it in your Framework, to create something like a root element.
-  # An operation with this identifier is not propagated to other clients.
-  # This is why everybode must create the same operation with this uid.
-  #
-  getReservedUniqueIdentifier: ()->
-    {
-      creator : '_'
-      op_number : "_#{@reserved_identifier_counter++}"
-      doSync: false
-    }
-
-  #
-  # Get the operation counter that describes the current state of the document.
-  #
-  getOperationCounter: (user_id)->
-    if not user_id?
-      res = {}
-      for user,ctn of @operation_counter
-        res[user] = ctn
-      res
-    else
-      @operation_counter[user_id]
-
-  isExpectedOperation: (o)->
-    @operation_counter[o.uid.creator] ?= 0
-    o.uid.op_number <= @operation_counter[o.uid.creator]
-    true #TODO: !! this could break stuff. But I dunno why
-
-  #
-  # Encode this operation in such a way that it can be parsed by remote peers.
-  # TODO: Make this more efficient!
-  _encode: (state_vector={})->
-    json = []
-    unknown = (user, o_number)->
-      if (not user?) or (not o_number?)
-        throw new Error "dah!"
-      not state_vector[user]? or state_vector[user] <= o_number
-
-    for u_name,user of @buffer
-      # TODO next, if @state_vector[user] <= state_vector[user]
-      for o_number,o of user
-        if o.uid.doSync and unknown(u_name, o_number)
-          # its necessary to send it, and not known in state_vector
-          o_json = o._encode()
-          if o.next_cl? # applies for all ops but the most right delimiter!
-            # search for the next _known_ operation. (When state_vector is {} then this is the Delimiter)
-            o_next = o.next_cl
-            while o_next.next_cl? and unknown(o_next.uid.creator, o_next.uid.op_number)
-              o_next = o_next.next_cl
-            o_json.next = o_next.getUid()
-          else if o.prev_cl? # most right delimiter only!
-            # same as the above with prev.
-            o_prev = o.prev_cl
-            while o_prev.prev_cl? and unknown(o_prev.uid.creator, o_prev.uid.op_number)
-              o_prev = o_prev.prev_cl
-            o_json.prev = o_prev.getUid()
-          json.push o_json
-
-    json
-
-  #
-  # Get the number of operations that were created by a user.
-  # Accordingly you will get the next operation number that is expected from that user.
-  # This will increment the operation counter.
-  #
-  getNextOperationIdentifier: (user_id)->
-    if not user_id?
-      user_id = @user_id
-    if not @operation_counter[user_id]?
-      @operation_counter[user_id] = 0
-    uid =
-      'creator' : user_id
-      'op_number' : @operation_counter[user_id]
-      'doSync' : true
-    @operation_counter[user_id]++
-    uid
-
-  #
-  # Retrieve an operation from a unique id.
-  #
-  # when uid has a "sub" property, the value of it will be applied
-  # on the operations retrieveSub method (which must! be defined)
-  #
-  getOperation: (uid)->
-    if uid.uid?
-      uid = uid.uid
-    o = @buffer[uid.creator]?[uid.op_number]
-    if uid.sub? and o?
-      o.retrieveSub uid.sub
-    else
-      o
-
-  #
-  # Add an operation to the HB. Note that this will not link it against
-  # other operations (it wont executed)
-  #
-  addOperation: (o)->
-    if not @buffer[o.uid.creator]?
-      @buffer[o.uid.creator] = {}
-    if @buffer[o.uid.creator][o.uid.op_number]?
-      throw new Error "You must not overwrite operations!"
-    if (o.uid.op_number.constructor isnt String) and (not @isExpectedOperation(o)) and (not o.fromHB?) # you already do this in the engine, so delete it here!
-      throw new Error "this operation was not expected!"
-    @addToCounter(o)
-    @buffer[o.uid.creator][o.uid.op_number] = o
-    o
-
-  removeOperation: (o)->
-    delete @buffer[o.uid.creator]?[o.uid.op_number]
-
-  # When the HB determines inconsistencies, then the invokeSync
-  # handler wil be called, which should somehow invoke the sync with another collaborator.
-  # The parameter of the sync handler is the user_id with wich an inconsistency was determined
-  setInvokeSyncHandler: (f)->
-    @invokeSync = f
-
-  # empty per default # TODO: do i need this?
-  invokeSync: ()->
-
-  # after you received the HB of another user (in the sync process),
-  # you renew your own state_vector to the state_vector of the other user
-  renewStateVector: (state_vector)->
-    for user,state of state_vector
-      if (not @operation_counter[user]?) or (@operation_counter[user] < state_vector[user])
-        @operation_counter[user] = state_vector[user]
-
-  #
-  # Increment the operation_counter that defines the current state of the Engine.
-  #
-  addToCounter: (o)->
-    if not @operation_counter[o.uid.creator]?
-      @operation_counter[o.uid.creator] = 0
-    if typeof o.uid.op_number is 'number' and o.uid.creator isnt @getUserId()
-      # TODO: check if operations are send in order
-      if o.uid.op_number is @operation_counter[o.uid.creator]
-        @operation_counter[o.uid.creator]++
-      else
-        @invokeSync o.uid.creator
-
-    #if @operation_counter[o.uid.creator] isnt (o.uid.op_number + 1)
-      #console.log (@operation_counter[o.uid.creator] - (o.uid.op_number + 1))
-      #console.log o
-      #throw new Error "You don't receive operations in the proper order. Try counting like this 0,1,2,3,4,.. ;)"
-
-module.exports = HistoryBuffer

lib/Types/BasicTypes.coffee

@@ -1,555 +0,0 @@
-module.exports = (HB)->
-  # @see Engine.parse
-  types = {}
-  execution_listener = []
-
-  #
-  # @private
-  # @abstract
-  # @nodoc
-  # A generic interface to operations.
-  #
-  # An operation has the following methods:
-  # * _encode: encodes an operation (needed only if instance of this operation is sent).
-  # * execute: execute the effects of this operations. Good examples are Insert-type and AddName-type
-  # * val: in the case that the operation holds a value
-  #
-  # Furthermore an encodable operation has a parser. We extend the parser object in order to parse encoded operations.
-  #
-  class types.Operation
-
-    #
-    # @param {Object} uid A unique identifier.
-    # If uid is undefined, a new uid will be created before at the end of the execution sequence
-    #
-    constructor: (uid)->
-      @is_deleted = false
-      @garbage_collected = false
-      @event_listeners = [] # TODO: rename to observers or sth like that
-      if uid?
-        @uid = uid
-
-    type: "Operation"
-
-    retrieveSub: ()->
-      throw new Error "sub properties are not enable on this operation type!"
-
-    #
-    # Add an event listener. It depends on the operation which events are supported.
-    # @param {Function} f f is executed in case the event fires.
-    #
-    observe: (f)->
-      @event_listeners.push f
-
-    #
-    # Deletes function from the observer list
-    # @see Operation.observe
-    #
-    # @overload unobserve(event, f)
-    #   @param f     {Function} The function that you want to delete 
-    unobserve: (f)->
-      @event_listeners = @event_listeners.filter (g)->
-        f isnt g
-
-    #
-    # Deletes all subscribed event listeners.
-    # This should be called, e.g. after this has been replaced.
-    # (Then only one replace event should fire. )
-    # This is also called in the cleanup method.
-    deleteAllObservers: ()->
-      @event_listeners = []
-
-    delete: ()->
-      (new types.Delete undefined, @).execute()
-      null
-
-    #
-    # Fire an event.
-    # TODO: Do something with timeouts. You don't want this to fire for every operation (e.g. insert).
-    # TODO: do you need callEvent+forwardEvent? Only one suffices probably
-    callEvent: ()->
-      @forwardEvent @, arguments...
-
-    #
-    # Fire an event and specify in which context the listener is called (set 'this').
-    # TODO: do you need this ?
-    forwardEvent: (op, args...)->
-      for f in @event_listeners
-        f.call op, args...
-
-    isDeleted: ()->
-      @is_deleted
-
-    applyDelete: (garbagecollect = true)->
-      if not @garbage_collected
-        #console.log "applyDelete: #{@type}"
-        @is_deleted = true
-        if garbagecollect
-          @garbage_collected = true
-          HB.addToGarbageCollector @
-
-    cleanup: ()->
-      #console.log "cleanup: #{@type}"
-      HB.removeOperation @
-      @deleteAllObservers()
-
-    #
-    # Set the parent of this operation.
-    #
-    setParent: (@parent)->
-
-    #
-    # Get the parent of this operation.
-    #
-    getParent: ()->
-      @parent
-
-    #
-    # Computes a unique identifier (uid) that identifies this operation.
-    #
-    getUid: ()->
-      if not @uid.noOperation?
-        @uid
-      else
-        @uid.alt # could be (safely) undefined
-
-    cloneUid: ()->
-      uid = {}
-      for n,v of @getUid()
-        uid[n] = v
-      uid
-
-    dontSync: ()->
-      @uid.doSync = false
-
-    #
-    # @private
-    # If not already done, set the uid
-    # Add this to the HB
-    # Notify the all the listeners.
-    #
-    execute: ()->
-      @is_executed = true
-      if not @uid?
-        # When this operation was created without a uid, then set it here.
-        # There is only one other place, where this can be done - before an Insertion
-        # is executed (because we need the creator_id)
-        @uid = HB.getNextOperationIdentifier()
-      if not @uid.noOperation?
-        HB.addOperation @
-        for l in execution_listener
-          l @_encode()
-      @
-
-    #
-    # @private
-    # Operations may depend on other operations (linked lists, etc.).
-    # The saveOperation and validateSavedOperations methods provide
-    # an easy way to refer to these operations via an uid or object reference.
-    #
-    # For example: We can create a new Delete operation that deletes the operation $o like this
-    #     - var d = new Delete(uid, $o);   or
-    #     - var d = new Delete(uid, $o.getUid());
-    # Either way we want to access $o via d.deletes. In the second case validateSavedOperations must be called first.
-    #
-    # @overload saveOperation(name, op_uid)
-    #   @param {String} name The name of the operation. After validating (with validateSavedOperations) the instantiated operation will be accessible via this[name].
-    #   @param {Object} op_uid A uid that refers to an operation
-    # @overload saveOperation(name, op)
-    #   @param {String} name The name of the operation. After calling this function op is accessible via this[name].
-    #   @param {Operation} op An Operation object
-    #
-    saveOperation: (name, op)->
-
-      #
-      # Every instance of $Operation must have an $execute function.
-      # We use duck-typing to check if op is instantiated since there
-      # could exist multiple classes of $Operation
-      #
-      if op?.execute?
-        # is instantiated
-        @[name] = op
-      else if op?
-        # not initialized. Do it when calling $validateSavedOperations()
-        @unchecked ?= {}
-        @unchecked[name] = op
-
-    #
-    # @private
-    # After calling this function all not instantiated operations will be accessible.
-    # @see Operation.saveOperation
-    #
-    # @return [Boolean] Whether it was possible to instantiate all operations.
-    #
-    validateSavedOperations: ()->
-      uninstantiated = {}
-      success = @
-      for name, op_uid of @unchecked
-        op = HB.getOperation op_uid
-        if op
-          @[name] = op
-        else
-          uninstantiated[name] = op_uid
-          success = false
-      delete @unchecked
-      if not success
-        @unchecked = uninstantiated
-      success
-
-  #
-  # @nodoc
-  # A simple Delete-type operation that deletes an operation.
-  #
-  class types.Delete extends types.Operation
-
-    #
-    # @param {Object} uid A unique identifier. If uid is undefined, a new uid will be created.
-    # @param {Object} deletes UID or reference of the operation that this to be deleted.
-    #
-    constructor: (uid, deletes)->
-      @saveOperation 'deletes', deletes
-      super uid
-
-    type: "Delete"
-
-    #
-    # @private
-    # Convert all relevant information of this operation to the json-format.
-    # This result can be sent to other clients.
-    #
-    _encode: ()->
-      {
-        'type': "Delete"
-        'uid': @getUid()
-        'deletes': @deletes.getUid()
-      }
-
-    #
-    # @private
-    # Apply the deletion.
-    #
-    execute: ()->
-      if @validateSavedOperations()
-        res = super
-        if res
-          @deletes.applyDelete @
-        res
-      else
-        false
-
-  #
-  # Define how to parse Delete operations.
-  #
-  types.Delete.parse = (o)->
-    {
-      'uid' : uid
-      'deletes': deletes_uid
-    } = o
-    new this(uid, deletes_uid)
-
-  #
-  # @nodoc
-  # A simple insert-type operation.
-  #
-  # An insert operation is always positioned between two other insert operations.
-  # Internally this is realized as associative lists, whereby each insert operation has a predecessor and a successor.
-  # For the sake of efficiency we maintain two lists:
-  #   - The short-list (abbrev. sl) maintains only the operations that are not deleted
-  #   - The complete-list (abbrev. cl) maintains all operations
-  #
-  class types.Insert extends types.Operation
-
-    #
-    # @param {Object} uid A unique identifier. If uid is undefined, a new uid will be created.
-    # @param {Operation} prev_cl The predecessor of this operation in the complete-list (cl)
-    # @param {Operation} next_cl The successor of this operation in the complete-list (cl)
-    #
-    constructor: (uid, prev_cl, next_cl, origin, parent)->
-      @saveOperation 'parent', parent
-      @saveOperation 'prev_cl', prev_cl
-      @saveOperation 'next_cl', next_cl
-      if origin?
-        @saveOperation 'origin', origin
-      else
-        @saveOperation 'origin', prev_cl
-      super uid
-
-    type: "Insert"
-
-    #
-    # set content to null and other stuff
-    # @private
-    #
-    applyDelete: (o)->
-      @deleted_by ?= []
-      callLater = false
-      if @parent? and not @isDeleted() and o? # o? : if not o?, then the delimiter deleted this Insertion. Furthermore, it would be wrong to call it. TODO: make this more expressive and save
-        # call iff wasn't deleted earlyer
-        callLater = true
-      if o?
-        @deleted_by.push o
-      garbagecollect = false
-      if @next_cl.isDeleted()
-        garbagecollect = true
-      super garbagecollect
-      if callLater
-        @callOperationSpecificDeleteEvents(o)
-      if @prev_cl?.isDeleted()
-        # garbage collect prev_cl
-        @prev_cl.applyDelete()
-
-    cleanup: ()->
-      if @next_cl.isDeleted()
-        # delete all ops that delete this insertion
-        for d in @deleted_by
-          d.cleanup()
-
-        # throw new Error "right is not deleted. inconsistency!, wrararar"
-        # change origin references to the right
-        o = @next_cl
-        while o.type isnt "Delimiter"
-          if o.origin is @
-            o.origin = @prev_cl
-          o = o.next_cl
-        # reconnect left/right
-        @prev_cl.next_cl = @next_cl
-        @next_cl.prev_cl = @prev_cl
-        super
-      # else
-      #   Someone inserted something in the meantime.
-      #   Remember: this can only be garbage collected when next_cl is deleted
-
-    #
-    # @private
-    # The amount of positions that $this operation was moved to the right.
-    #
-    getDistanceToOrigin: ()->
-      d = 0
-      o = @prev_cl
-      while true
-        if @origin is o
-          break
-        d++
-        o = o.prev_cl
-      d
-
-    #
-    # @private
-    # Include this operation in the associative lists.
-    execute: ()->
-      if not @validateSavedOperations()
-        return false
-      else
-        if @parent?
-          if not @prev_cl?
-            @prev_cl = @parent.beginning
-          if not @origin?
-            @origin = @parent.beginning
-          if not @next_cl?
-            @next_cl = @parent.end
-        if @prev_cl?
-          distance_to_origin = @getDistanceToOrigin() # most cases: 0
-          o = @prev_cl.next_cl
-          i = distance_to_origin # loop counter
-
-          # $this has to find a unique position between origin and the next known character
-          # case 1: $origin equals $o.origin: the $creator parameter decides if left or right
-          #         let $OL= [o1,o2,o3,o4], whereby $this is to be inserted between o1 and o4
-          #         o2,o3 and o4 origin is 1 (the position of o2)
-          #         there is the case that $this.creator < o2.creator, but o3.creator < $this.creator
-          #         then o2 knows o3. Since on another client $OL could be [o1,o3,o4] the problem is complex
-          #         therefore $this would be always to the right of o3
-          # case 2: $origin < $o.origin
-          #         if current $this insert_position > $o origin: $this ins
-          #         else $insert_position will not change
-          #         (maybe we encounter case 1 later, then this will be to the right of $o)
-          # case 3: $origin > $o.origin
-          #         $this insert_position is to the left of $o (forever!)
-          while true
-            if o isnt @next_cl
-              # $o happened concurrently
-              if o.getDistanceToOrigin() is i
-                # case 1
-                if o.uid.creator < @uid.creator
-                  @prev_cl = o
-                  distance_to_origin = i + 1
-                else
-                  # nop
-              else if o.getDistanceToOrigin() < i
-                # case 2
-                if i - distance_to_origin <= o.getDistanceToOrigin()
-                  @prev_cl = o
-                  distance_to_origin = i + 1
-                else
-                  #nop
-              else
-                # case 3
-                break
-              i++
-              o = o.next_cl
-            else
-              # $this knows that $o exists,
-              break
-          # now reconnect everything
-          @next_cl = @prev_cl.next_cl
-          @prev_cl.next_cl = @
-          @next_cl.prev_cl = @
-
-        @setParent @prev_cl.getParent() # do Insertions always have a parent?
-        super # notify the execution_listeners
-        @callOperationSpecificInsertEvents()
-        @
-
-    callOperationSpecificInsertEvents: ()->
-      @parent?.callEvent [
-        type: "insert"
-        position: @getPosition()
-        object: @parent
-        changedBy: @uid.creator
-        value: @content
-      ]
-
-    callOperationSpecificDeleteEvents: (o)->
-      @parent.callEvent [
-        type: "delete"
-        position: @getPosition()
-        object: @parent # TODO: You can combine getPosition + getParent in a more efficient manner! (only left Delimiter will hold @parent)
-        length: 1
-        changedBy: o.uid.creator
-      ]
-
-    #
-    # Compute the position of this operation.
-    #
-    getPosition: ()->
-      position = 0
-      prev = @prev_cl
-      while true
-        if prev instanceof types.Delimiter
-          break
-        if not prev.isDeleted()
-          position++
-        prev = prev.prev_cl
-      position
-
-  #
-  # @nodoc
-  # Defines an object that is cannot be changed. You can use this to set an immutable string, or a number.
-  #
-  class types.ImmutableObject extends types.Operation
-
-    #
-    # @param {Object} uid A unique identifier. If uid is undefined, a new uid will be created.
-    # @param {Object} content
-    #
-    constructor: (uid, @content)->
-      super uid
-
-    type: "ImmutableObject"
-
-    #
-    # @return [String] The content of this operation.
-    #
-    val : ()->
-      @content
-
-    #
-    # Encode this operation in such a way that it can be parsed by remote peers.
-    #
-    _encode: ()->
-      json = {
-        'type': @type
-        'uid' : @getUid()
-        'content' : @content
-      }
-      json
-
-  types.ImmutableObject.parse = (json)->
-    {
-      'uid' : uid
-      'content' : content
-    } = json
-    new this(uid, content)
-
-  #
-  # @nodoc
-  # A delimiter is placed at the end and at the beginning of the associative lists.
-  # This is necessary in order to have a beginning and an end even if the content
-  # of the Engine is empty.
-  #
-  class types.Delimiter extends types.Operation
-    #
-    # @param {Object} uid A unique identifier. If uid is undefined, a new uid will be created.
-    # @param {Operation} prev_cl The predecessor of this operation in the complete-list (cl)
-    # @param {Operation} next_cl The successor of this operation in the complete-list (cl)
-    #
-    constructor: (prev_cl, next_cl, origin)->
-      @saveOperation 'prev_cl', prev_cl
-      @saveOperation 'next_cl', next_cl
-      @saveOperation 'origin', prev_cl
-      super {noOperation: true}
-
-    type: "Delimiter"
-
-    applyDelete: ()->
-      super()
-      o = @prev_cl
-      while o?
-        o.applyDelete()
-        o = o.prev_cl
-      undefined
-
-    cleanup: ()->
-      super()
-
-    #
-    # @private
-    #
-    execute: ()->
-      if @unchecked?['next_cl']?
-        super
-      else if @unchecked?['prev_cl']
-        if @validateSavedOperations()
-          if @prev_cl.next_cl?
-            throw new Error "Probably duplicated operations"
-          @prev_cl.next_cl = @
-          super
-        else
-          false
-      else if @prev_cl? and not @prev_cl.next_cl?
-        delete @prev_cl.unchecked.next_cl
-        @prev_cl.next_cl = @
-        super
-      else if @prev_cl? or @next_cl? or true # TODO: are you sure? This can happen right?
-        super
-      #else
-      #  throw new Error "Delimiter is unsufficient defined!"
-
-    #
-    # @private
-    #
-    _encode: ()->
-      {
-        'type' : @type
-        'uid' : @getUid()
-        'prev' : @prev_cl?.getUid()
-        'next' : @next_cl?.getUid()
-      }
-
-  types.Delimiter.parse = (json)->
-    {
-    'uid' : uid
-    'prev' : prev
-    'next' : next
-    } = json
-    new this(uid, prev, next)
-
-  # This is what this module exports after initializing it with the HistoryBuffer
-  {
-    'types' : types
-    'execution_listener' : execution_listener
-  }
-
-
-
-

lib/Types/JsonTypes.coffee

@@ -1,148 +0,0 @@
-text_types_uninitialized = require "./TextTypes"
-
-module.exports = (HB)->
-  text_types = text_types_uninitialized HB
-  types = text_types.types
-
-  #
-  # Manages Object-like values.
-  #
-  class types.Object extends types.MapManager
-
-    #
-    # Identifies this class.
-    # Use it to check whether this is a json-type or something else.
-    #
-    # @example
-    #   var x = y.val('unknown')
-    #   if (x.type === "Object") {
-    #     console.log JSON.stringify(x.toJson())
-    #   }
-    #
-    type: "Object"
-
-    applyDelete: ()->
-      super()
-
-    cleanup: ()->
-      super()
-
-
-    #
-    # Transform this to a Json. If your browser supports Object.observe it will be transformed automatically when a change arrives.
-    # Otherwise you will loose all the sharing-abilities (the new object will be a deep clone)!
-    # @return {Json}
-    #
-    # TODO: at the moment you don't consider changing of properties.
-    # E.g.: let x = {a:[]}. Then x.a.push 1 wouldn't change anything
-    #
-    toJson: (transform_to_value = false)->
-      if not @bound_json? or not Object.observe? or true # TODO: currently, you are not watching mutable strings for changes, and, therefore, the @bound_json is not updated. TODO TODO  wuawuawua easy
-        val = @val()
-        json = {}
-        for name, o of val
-          if o instanceof types.Object
-            json[name] = o.toJson(transform_to_value)
-          else if o instanceof types.Array
-            json[name] = o.toJson(transform_to_value)
-          else if transform_to_value and o instanceof types.Operation
-            json[name] = o.val()
-          else
-            json[name] = o
-        @bound_json = json
-        if Object.observe?
-          that = @
-          Object.observe @bound_json, (events)->
-            for event in events
-              if not event.changedBy? and (event.type is "add" or event.type = "update")
-                # this event is not created by Y.
-                that.val(event.name, event.object[event.name])
-          @observe (events)->
-            for event in events
-              if event.created_ isnt HB.getUserId()
-                notifier = Object.getNotifier(that.bound_json)
-                oldVal = that.bound_json[event.name]
-                if oldVal?
-                  notifier.performChange 'update', ()->
-                      that.bound_json[event.name] = that.val(event.name)
-                    , that.bound_json
-                  notifier.notify
-                    object: that.bound_json
-                    type: 'update'
-                    name: event.name
-                    oldValue: oldVal
-                    changedBy: event.changedBy
-                else
-                  notifier.performChange 'add', ()->
-                      that.bound_json[event.name] = that.val(event.name)
-                    , that.bound_json
-                  notifier.notify
-                    object: that.bound_json
-                    type: 'add'
-                    name: event.name
-                    oldValue: oldVal
-                    changedBy:event.changedBy
-      @bound_json
-
-    #
-    # @overload val()
-    #   Get this as a Json object.
-    #   @return [Json]
-    #
-    # @overload val(name)
-    #   Get value of a property.
-    #   @param {String} name Name of the object property.
-    #   @return [Object Type||String|Object] Depending on the value of the property. If mutable it will return a Operation-type object, if immutable it will return String/Object.
-    #
-    # @overload val(name, content)
-    #   Set a new property.
-    #   @param {String} name Name of the object property.
-    #   @param {Object|String} content Content of the object property.
-    #   @return [Object Type] This object. (supports chaining)
-    #
-    val: (name, content)->
-      if name? and arguments.length > 1
-        if content? and content.constructor?
-          type = types[content.constructor.name]
-          if type? and type.create?
-            args = []
-            for i in [1...arguments.length]
-              args.push arguments[i]
-            o = type.create.apply null, args
-            super name, o
-          else
-            throw new Error "The #{content.constructor.name}-type is not (yet) supported in Y."
-        else
-          super name, content
-      else # is this even necessary ? I have to define every type anyway.. (see Number type below)
-        super name
-
-    #
-    # @private
-    #
-    _encode: ()->
-      {
-        'type' : @type
-        'uid' : @getUid()
-      }
-
-  types.Object.parse = (json)->
-    {
-      'uid' : uid
-    } = json
-    new this(uid)
-
-  types.Object.create = (content, mutable)->
-    json = new types.Object().execute()
-    for n,o of content
-      json.val n, o, mutable
-    json
-
-
-  types.Number = {}
-  types.Number.create = (content)->
-    content
-
-  text_types
-
-

lib/Types/StructuredTypes.coffee

@@ -1,357 +0,0 @@
-basic_types_uninitialized = require "./BasicTypes"
-
-module.exports = (HB)->
-  basic_types = basic_types_uninitialized HB
-  types = basic_types.types
-
-  #
-  # @nodoc
-  # Manages map like objects. E.g. Json-Type and XML attributes.
-  #
-  class types.MapManager extends types.Operation
-
-    #
-    # @param {Object} uid A unique identifier. If uid is undefined, a new uid will be created.
-    #
-    constructor: (uid)->
-      @map = {}
-      super uid
-
-    type: "MapManager"
-
-    applyDelete: ()->
-      for name,p of @map
-        p.applyDelete()
-      super()
-
-    cleanup: ()->
-      super()
-
-    #
-    # @see JsonTypes.val
-    #
-    val: (name, content)->
-      if arguments.length > 1
-        @retrieveSub(name).replace content
-        @
-      else if name?
-        prop = @map[name]
-        if prop? and not prop.isContentDeleted()
-          prop.val()
-        else
-          undefined
-      else
-        result = {}
-        for name,o of @map
-          if not o.isContentDeleted()
-            result[name] = o.val()
-        result
-
-    delete: (name)->
-      @map[name]?.deleteContent()
-      @
-
-    retrieveSub: (property_name)->
-      if not @map[property_name]?
-        event_properties =
-          name: property_name
-        event_this = @
-        map_uid = @cloneUid()
-        map_uid.sub = property_name
-        rm_uid =
-          noOperation: true
-          alt: map_uid
-        rm = new types.ReplaceManager event_properties, event_this, rm_uid # this operation shall not be saved in the HB
-        @map[property_name] = rm
-        rm.setParent @, property_name
-        rm.execute()
-      @map[property_name]
-
-  #
-  # @nodoc
-  # Manages a list of Insert-type operations.
-  #
-  class types.ListManager extends types.Operation
-
-    #
-    # A ListManager maintains a non-empty list that has a beginning and an end (both Delimiters!)
-    # @param {Object} uid A unique identifier. If uid is undefined, a new uid will be created.
-    # @param {Delimiter} beginning Reference or Object.
-    # @param {Delimiter} end Reference or Object.
-    constructor: (uid)->
-      @beginning = new types.Delimiter undefined, undefined
-      @end =       new types.Delimiter @beginning, undefined
-      @beginning.next_cl = @end
-      @beginning.execute()
-      @end.execute()
-      super uid
-
-    type: "ListManager"
-
-    #
-    # @private
-    # @see Operation.execute
-    #
-    execute: ()->
-      if @validateSavedOperations()
-        @beginning.setParent @
-        @end.setParent @
-        super
-      else
-        false
-
-    # Get the element previous to the delemiter at the end
-    getLastOperation: ()->
-      @end.prev_cl
-
-    # similar to the above
-    getFirstOperation: ()->
-      @beginning.next_cl
-
-    # Transforms the the list to an array
-    # Doesn't return left-right delimiter.
-    toArray: ()->
-      o = @beginning.next_cl
-      result = []
-      while o isnt @end
-        result.push o
-        o = o.next_cl
-      result
-
-    #
-    # Retrieves the x-th not deleted element.
-    # e.g. "abc" : the 1th character is "a"
-    # the 0th character is the left Delimiter
-    #
-    getOperationByPosition: (position)->
-      o = @beginning
-      while true
-        # find the i-th op
-        if o instanceof types.Delimiter and o.prev_cl?
-          # the user or you gave a position parameter that is to big
-          # for the current array. Therefore we reach a Delimiter.
-          # Then, we'll just return the last character.
-          o = o.prev_cl
-          while o.isDeleted() or not (o instanceof types.Delimiter)
-            o = o.prev_cl
-          break
-        if position <= 0 and not o.isDeleted()
-          break
-
-        o = o.next_cl
-        if not o.isDeleted()
-          position -= 1
-      o
-
-  #
-  # @nodoc
-  # Adds support for replace. The ReplaceManager manages Replaceable operations.
-  # Each Replaceable holds a value that is now replaceable.
-  #
-  # The TextType-type has implemented support for replace
-  # @see TextType
-  #
-  class types.ReplaceManager extends types.ListManager
-    #
-    # @param {Object} event_properties Decorates the event that is thrown by the RM
-    # @param {Object} event_this The object on which the event shall be executed
-    # @param {Operation} initial_content Initialize this with a Replaceable that holds the initial_content.
-    # @param {Object} uid A unique identifier. If uid is undefined, a new uid will be created.
-    # @param {Delimiter} beginning Reference or Object.
-    # @param {Delimiter} end Reference or Object.
-    constructor: (@event_properties, @event_this, uid, beginning, end)->
-      if not @event_properties['object']?
-        @event_properties['object'] = @event_this
-      super uid, beginning, end
-
-    type: "ReplaceManager"
-
-    applyDelete: ()->
-      o = @beginning
-      while o?
-        o.applyDelete()
-        o = o.next_cl
-      super()
-
-    cleanup: ()->
-      super()
-
-    #
-    # This doesn't throw the same events as the ListManager. Therefore, the
-    # Replaceables also not throw the same events.
-    # So, ReplaceManager and ListManager both implement
-    # these functions that are called when an Insertion is executed (at the end).
-    #
-    #
-    callEventDecorator: (events)->
-      if not @isDeleted()
-        for event in events
-          for name,prop of @event_properties
-            event[name] = prop
-        @event_this.callEvent events
-      undefined
-
-    #
-    # Replace the existing word with a new word.
-    #
-    # @param content {Operation} The new value of this ReplaceManager.
-    # @param replaceable_uid {UID} Optional: Unique id of the Replaceable that is created
-    #
-    replace: (content, replaceable_uid)->
-      o = @getLastOperation()
-      relp = (new types.Replaceable content, @, replaceable_uid, o, o.next_cl).execute()
-      # TODO: delete repl (for debugging)
-      undefined
-
-    isContentDeleted: ()->
-      @getLastOperation().isDeleted()
-
-    deleteContent: ()->
-      (new types.Delete undefined, @getLastOperation().uid).execute()
-      undefined
-
-    #
-    # Get the value of this
-    # @return {String}
-    #
-    val: ()->
-      o = @getLastOperation()
-      #if o instanceof types.Delimiter
-        # throw new Error "Replace Manager doesn't contain anything."
-      o.val?() # ? - for the case that (currently) the RM does not contain anything (then o is a Delimiter)
-
-    #
-    # Encode this operation in such a way that it can be parsed by remote peers.
-    #
-    _encode: ()->
-      json =
-        {
-          'type': @type
-          'uid' : @getUid()
-          'beginning' : @beginning.getUid()
-          'end' : @end.getUid()
-        }
-      json
-
-  #
-  # @nodoc
-  # The ReplaceManager manages Replaceables.
-  # @see ReplaceManager
-  #
-  class types.Replaceable extends types.Insert
-
-    #
-    # @param {Operation} content The value that this Replaceable holds.
-    # @param {ReplaceManager} parent Used to replace this Replaceable with another one.
-    # @param {Object} uid A unique identifier. If uid is undefined, a new uid will be created.
-    #
-    constructor: (content, parent, uid, prev, next, origin, is_deleted)->
-      # see encode to see, why we are doing it this way
-      if content? and content.creator?
-        @saveOperation 'content', content
-      else
-        @content = content
-      @saveOperation 'parent', parent
-      super uid, prev, next, origin # Parent is already saved by Replaceable
-      @is_deleted = is_deleted
-
-    type: "Replaceable"
-
-    #
-    # Return the content that this operation holds.
-    #
-    val: ()->
-      @content
-
-    applyDelete: ()->
-      res = super
-      if @content?
-        if @next_cl.type isnt "Delimiter"
-          @content.deleteAllObservers?()
-        @content.applyDelete?()
-        @content.dontSync?()
-      @content = null
-      res
-
-    cleanup: ()->
-      super
-
-    #
-    # This is called, when the Insert-type was successfully executed.
-    # TODO: consider doing this in a more consistent manner. This could also be
-    # done with execute. But currently, there are no specital Insert-types for ListManager.
-    #
-    callOperationSpecificInsertEvents: ()->
-      if @next_cl.type is "Delimiter" and @prev_cl.type isnt "Delimiter"
-        # this replaces another Replaceable
-        if not @is_deleted # When this is received from the HB, this could already be deleted!
-          old_value = @prev_cl.content
-          @parent.callEventDecorator [
-            type: "update"
-            changedBy: @uid.creator
-            oldValue: old_value
-          ]
-        @prev_cl.applyDelete()
-      else if @next_cl.type isnt "Delimiter"
-        # This won't be recognized by the user, because another
-        # concurrent operation is set as the current value of the RM
-        @applyDelete()
-      else # prev _and_ next are Delimiters. This is the first created Replaceable in the RM
-        @parent.callEventDecorator [
-          type: "add"
-          changedBy: @uid.creator
-        ]
-      undefined
-
-    callOperationSpecificDeleteEvents: (o)->
-      if @next_cl.type is "Delimiter"
-        @parent.callEventDecorator [
-          type: "delete"
-          changedBy: o.uid.creator
-          oldValue: @content
-        ]
-
-    #
-    # Encode this operation in such a way that it can be parsed by remote peers.
-    #
-    _encode: ()->
-      json =
-        {
-          'type': @type
-          'parent' : @parent.getUid()
-          'prev': @prev_cl.getUid()
-          'next': @next_cl.getUid()
-          'origin' : @origin.getUid()
-          'uid' : @getUid()
-          'is_deleted': @is_deleted
-        }
-      if @content instanceof types.Operation
-        json['content'] = @content.getUid()
-      else
-        # This could be a security concern.
-        # Throw error if the users wants to trick us
-        if @content? and @content.creator?
-          throw new Error "You must not set creator here!"
-        json['content'] = @content
-      json
-
-  types.Replaceable.parse = (json)->
-    {
-      'content' : content
-      'parent' : parent
-      'uid' : uid
-      'prev': prev
-      'next': next
-      'origin' : origin
-      'is_deleted': is_deleted
-    } = json
-    new this(content, parent, uid, prev, next, origin, is_deleted)
-
-
-  basic_types
-
-
-
-
-
-

lib/Types/TextTypes.coffee

@@ -1,522 +0,0 @@
-structured_types_uninitialized = require "./StructuredTypes"
-
-module.exports = (HB)->
-  structured_types = structured_types_uninitialized HB
-  types = structured_types.types
-  parser = structured_types.parser
-
-  #
-  # @nodoc
-  # Extends the basic Insert type to an operation that holds a text value
-  #
-  class types.TextInsert extends types.Insert
-    #
-    # @param {String} content The content of this Insert-type Operation. Usually you restrict the length of content to size 1
-    # @param {Object} uid A unique identifier. If uid is undefined, a new uid will be created.
-    #
-    constructor: (content, uid, prev, next, origin, parent)->
-      if content?.creator
-        @saveOperation 'content', content
-      else
-        @content = content
-      super uid, prev, next, origin, parent
-
-    type: "TextInsert"
-
-    #
-    # Retrieve the effective length of the $content of this operation.
-    #
-    getLength: ()->
-      if @isDeleted()
-        0
-      else
-        @content.length
-
-    applyDelete: ()->
-      super # no braces indeed!
-      if @content instanceof types.Operation
-        @content.applyDelete()
-      @content = null
-
-    execute: ()->
-      if not @validateSavedOperations()
-        return false
-      else
-        if @content instanceof types.Operation
-          @content.insert_parent = @
-        super()
-
-    #
-    # The result will be concatenated with the results from the other insert operations
-    # in order to retrieve the content of the engine.
-    # @see HistoryBuffer.toExecutedArray
-    #
-    val: (current_position)->
-      if @isDeleted() or not @content?
-        ""
-      else
-        @content
-
-    #
-    # Convert all relevant information of this operation to the json-format.
-    # This result can be send to other clients.
-    #
-    _encode: ()->
-      json =
-        {
-          'type': @type
-          'uid' : @getUid()
-          'prev': @prev_cl.getUid()
-          'next': @next_cl.getUid()
-          'origin': @origin.getUid()
-          'parent': @parent.getUid()
-        }
-
-      if @content?.getUid?
-        json['content'] = @content.getUid()
-      else
-        json['content'] = @content
-      json
-
-  types.TextInsert.parse = (json)->
-    {
-      'content' : content
-      'uid' : uid
-      'prev': prev
-      'next': next
-      'origin' : origin
-      'parent' : parent
-    } = json
-    new types.TextInsert content, uid, prev, next, origin, parent
-
-
-  class types.Array extends types.ListManager
-
-    type: "Array"
-
-    applyDelete: ()->
-      o = @end
-      while o?
-        o.applyDelete()
-        o = o.prev_cl
-      super()
-
-    cleanup: ()->
-      super()
-
-    toJson: (transform_to_value = false)->
-      val = @val()
-      for i, o in val
-        if o instanceof types.Object
-          o.toJson(transform_to_value)
-        else if o instanceof types.Array
-          o.toJson(transform_to_value)
-        else if transform_to_value and o instanceof types.Operation
-          o.val()
-        else
-          o
-
-    val: (pos)->
-      if pos?
-        o = @getOperationByPosition(pos+1)
-        if not (o instanceof types.Delimiter)
-          o.val()
-        else
-          throw new Error "this position does not exist"
-      else
-        o = @beginning.next_cl
-        result = []
-        while o isnt @end
-          if not o.isDeleted()
-            result.push o.val()
-          o = o.next_cl
-        result
-
-    push: (content)->
-      @insertAfter @end.prev_cl, content
-
-    insertAfter: (left, content, options)->
-      createContent = (content, options)->
-        if content? and content.constructor?
-          type = types[content.constructor.name]
-          if type? and type.create?
-            type.create content, options
-          else
-            throw new Error "The #{content.constructor.name}-type is not (yet) supported in Y."
-        else
-          content
-
-      right = left.next_cl
-      while right.isDeleted()
-        right = right.next_cl # find the first character to the right, that is not deleted. In the case that position is 0, its the Delimiter.
-      left = right.prev_cl
-
-      if content instanceof types.Operation
-        (new types.TextInsert content, undefined, left, right).execute()
-      else
-        for c in content
-          tmp = (new types.TextInsert createContent(c, options), undefined, left, right).execute()
-          left = tmp
-      @
-
-    #
-    # Inserts a string into the word.
-    #
-    # @return {Array Type} This String object.
-    #
-    insert: (position, content, options)->
-      ith = @getOperationByPosition position
-      # the (i-1)th character. e.g. "abc" the 1th character is "a"
-      # the 0th character is the left Delimiter
-      @insertAfter ith, [content], options
-
-    #
-    # Deletes a part of the word.
-    #
-    # @return {Array Type} This String object
-    #
-    delete: (position, length)->
-      o = @getOperationByPosition(position+1) # position 0 in this case is the deletion of the first character
-
-      delete_ops = []
-      for i in [0...length]
-        if o instanceof types.Delimiter
-          break
-        d = (new types.Delete undefined, o).execute()
-        o = o.next_cl
-        while (not (o instanceof types.Delimiter)) and o.isDeleted()
-          o = o.next_cl
-        delete_ops.push d._encode()
-      @
-
-    #
-    # @private
-    # Encode this operation in such a way that it can be parsed by remote peers.
-    #
-    _encode: ()->
-      json = {
-        'type': @type
-        'uid' : @getUid()
-      }
-      json
-
-  types.Array.parse = (json)->
-    {
-      'uid' : uid
-    } = json
-    new this(uid)
-
-  types.Array.create = (content, mutable)->
-    if (mutable is "mutable")
-      list = new types.Array().execute()
-      ith = list.getOperationByPosition 0
-      list.insertAfter ith, content
-      list
-    else if (not mutable?) or (mutable is "immutable")
-      content
-    else
-      throw new Error "Specify either \"mutable\" or \"immutable\"!!"
-
-  #
-  # Handles a String-like data structures with support for insert/delete at a word-position.
-  # @note Currently, only Text is supported!
-  #
-  class types.String extends types.Array
-
-    #
-    # @private
-    # @param {Object} uid A unique identifier. If uid is undefined, a new uid will be created.
-    #
-    constructor: (uid)->
-      @textfields = []
-      super uid
-
-    #
-    # Identifies this class.
-    # Use it to check whether this is a word-type or something else.
-    #
-    # @example
-    #   var x = y.val('unknown')
-    #   if (x.type === "String") {
-    #     console.log JSON.stringify(x.toJson())
-    #   }
-    #
-    type: "String"
-
-    #
-    # Get the String-representation of this word.
-    # @return {String} The String-representation of this object.
-    #
-    val: ()->
-      c = for o in @toArray()
-        if o.val?
-          o.val()
-        else
-          ""
-      c.join('')
-
-    #
-    # Same as String.val
-    # @see String.val
-    #
-    toString: ()->
-      @val()
-
-    #
-    # Inserts a string into the word.
-    #
-    # @return {Array Type} This String object.
-    #
-    insert: (position, content, options)->
-      ith = @getOperationByPosition position
-      # the (i-1)th character. e.g. "abc" the 1th character is "a"
-      # the 0th character is the left Delimiter
-      @insertAfter ith, content, options
-
-    #
-    # Bind this String to a textfield or input field.
-    #
-    # @example
-    #   var textbox = document.getElementById("textfield");
-    #   y.bind(textbox);
-    #
-    bind: (textfield, dom_root)->
-      dom_root ?= window
-      if (not dom_root.getSelection?)
-        dom_root = window
-
-      # don't duplicate!
-      for t in @textfields
-        if t is textfield
-          return
-      creator_token = false;
-
-      word = @
-      textfield.value = @val()
-      @textfields.push textfield
-
-      if textfield.selectionStart? and textfield.setSelectionRange?
-        createRange = (fix)->
-          left = textfield.selectionStart
-          right = textfield.selectionEnd
-          if fix?
-            left = fix left
-            right = fix right
-          {
-            left: left
-            right: right
-          }
-
-        writeRange = (range)->
-          writeContent word.val()
-          textfield.setSelectionRange range.left, range.right
-
-        writeContent = (content)->
-          textfield.value = content
-      else
-        createRange = (fix)->
-          s = dom_root.getSelection()
-          clength = textfield.textContent.length
-          left = Math.min s.anchorOffset, clength
-          right = Math.min s.focusOffset, clength
-          if fix?
-            left = fix left
-            right = fix right
-          {
-            left: left
-            right: right
-            isReal: true
-          }
-
-        writeRange = (range)->
-          writeContent word.val()
-          textnode = textfield.childNodes[0]
-          if range.isReal and textnode?
-            if range.left < 0
-              range.left = 0
-            range.right = Math.max range.left, range.right
-            if range.right > textnode.length
-              range.right = textnode.length
-            range.left = Math.min range.left, range.right
-            r = document.createRange()
-            r.setStart(textnode, range.left)
-            r.setEnd(textnode, range.right)
-            s = window.getSelection()
-            s.removeAllRanges()
-            s.addRange(r)
-        writeContent = (content)->
-          append = ""
-          if content[content.length - 1] is " "
-            content = content.slice(0,content.length-1)
-            append = '&nbsp;'
-          textfield.textContent = content
-          textfield.innerHTML += append
-
-      writeContent this.val()
-
-      @observe (events)->
-        for event in events
-          if not creator_token
-            if event.type is "insert"
-              o_pos = event.position
-              fix = (cursor)->
-                if cursor <= o_pos
-                  cursor
-                else
-                  cursor += 1
-                  cursor
-              r = createRange fix
-              writeRange r
-
-            else if event.type is "delete"
-              o_pos = event.position
-              fix = (cursor)->
-                if cursor < o_pos
-                  cursor
-                else
-                  cursor -= 1
-                  cursor
-              r = createRange fix
-              writeRange r
-
-      # consume all text-insert changes.
-      textfield.onkeypress = (event)->
-        if word.is_deleted
-          # if word is deleted, do not do anything ever again
-          textfield.onkeypress = null
-          return true
-        creator_token = true
-        char = null
-        if event.key?
-          if event.charCode is 32
-            char = " "
-          else if event.keyCode is 13
-            char = '\n'
-          else
-            char = event.key
-        else
-          char = window.String.fromCharCode event.keyCode
-        if char.length > 1
-          return true
-        else if char.length > 0
-          r = createRange()
-          pos = Math.min r.left, r.right
-          diff = Math.abs(r.right - r.left)
-          word.delete pos, diff
-          word.insert pos, char
-          r.left = pos + char.length
-          r.right = r.left
-          writeRange r
-
-        event.preventDefault()
-        creator_token = false
-        false
-
-      textfield.onpaste = (event)->
-        if word.is_deleted
-          # if word is deleted, do not do anything ever again
-          textfield.onpaste = null
-          return true
-        event.preventDefault()
-      textfield.oncut = (event)->
-        if word.is_deleted
-          # if word is deleted, do not do anything ever again
-          textfield.oncut = null
-          return true
-        event.preventDefault()
-
-      #
-      # consume deletes. Note that
-      #   chrome: won't consume deletions on keypress event.
-      #   keyCode is deprecated. BUT: I don't see another way.
-      #     since event.key is not implemented in the current version of chrome.
-      #     Every browser supports keyCode. Let's stick with it for now..
-      #
-      textfield.onkeydown = (event)->
-        creator_token = true
-        if word.is_deleted
-          # if word is deleted, do not do anything ever again
-          textfield.onkeydown = null
-          return true
-        r = createRange()
-        pos = Math.min(r.left, r.right, word.val().length)
-        diff = Math.abs(r.left - r.right)
-        if event.keyCode? and event.keyCode is 8 # Backspace
-          if diff > 0
-            word.delete pos, diff
-            r.left = pos
-            r.right = pos
-            writeRange r
-          else
-            if event.ctrlKey? and event.ctrlKey
-              val = word.val()
-              new_pos = pos
-              del_length = 0
-              if pos > 0
-                new_pos--
-                del_length++
-              while new_pos > 0 and val[new_pos] isnt " " and val[new_pos] isnt '\n'
-                new_pos--
-                del_length++
-              word.delete new_pos, (pos-new_pos)
-              r.left = new_pos
-              r.right = new_pos
-              writeRange r
-            else
-              if pos > 0
-                word.delete (pos-1), 1
-                r.left = pos-1
-                r.right = pos-1
-                writeRange r
-          event.preventDefault()
-          creator_token = false
-          return false
-        else if event.keyCode? and event.keyCode is 46 # Delete
-          if diff > 0
-            word.delete pos, diff
-            r.left = pos
-            r.right = pos
-            writeRange r
-          else
-            word.delete pos, 1
-            r.left = pos
-            r.right = pos
-            writeRange r
-          event.preventDefault()
-          creator_token = false
-          return false
-        else
-          creator_token = false
-          true
-
-    #
-    # @private
-    # Encode this operation in such a way that it can be parsed by remote peers.
-    #
-    _encode: ()->
-      json = {
-        'type': @type
-        'uid' : @getUid()
-      }
-      json
-
-  types.String.parse = (json)->
-    {
-      'uid' : uid
-    } = json
-    new this(uid)
-
-  types.String.create = (content, mutable)->
-    if (mutable is "mutable")
-      word = new types.String().execute()
-      word.insert 0, content
-      word
-    else if (not mutable?) or (mutable is "immutable")
-      content
-    else
-      throw new Error "Specify either \"mutable\" or \"immutable\"!!"
-
-
-  structured_types
-
-

lib/Types/XmlTypes.unused

@@ -1,367 +0,0 @@
-###
-json_types_uninitialized = require "./JsonTypes"
-
-# some dom implementations may call another dom.method that simulates the behavior of another.
-# For example xml.insertChild(dom) , wich inserts an element at the end, and xml.insertAfter(dom,null) wich does the same
-# But Y's proxy may be called only once!
-proxy_token = false
-dont_proxy = (f)->
-  proxy_token = true
-  try
-    f()
-  catch e
-    proxy_token = false
-    throw new Error e
-  proxy_token = false
-
-_proxy = (f_name, f)->
-  old_f = @[f_name]
-  if old_f?
-    @[f_name] = ()->
-      if not proxy_token and not @_y?.isDeleted()
-        that = this
-        args = arguments
-        dont_proxy ()->
-          f.apply that, args
-          old_f.apply that, args
-      else
-        old_f.apply this, arguments
-  #else
-  #  @[f_name] = f
-Element?.prototype._proxy = _proxy
-
-
-module.exports = (HB)->
-  json_types = json_types_uninitialized HB
-  types = json_types.types
-  parser = json_types.parser
-
-  #
-  # Manages XML types
-  # Not supported:
-  # * Attribute nodes
-  # * Real replace of child elements (to much overhead). Currently, the new element is inserted after the 'replaced' element, and then it is deleted.
-  # * Namespaces (*NS)
-  # * Browser specific methods (webkit-* operations)
-  class XmlType extends types.Insert
-
-    constructor: (uid, @tagname, attributes, elements, @xml)->
-      ### In case you make this instanceof Insert again
-      if prev? and (not next?) and prev.type?
-        # adjust what you actually mean. you want to insert after prev, then
-        # next is not defined. but we only insert after non-deleted elements.
-        # This is also handled in TextInsert.
-        while prev.isDeleted()
-          prev = prev.prev_cl
-        next = prev.next_cl
-      ###
-
-      super(uid)
-
-
-      if @xml?._y?
-        d = new types.Delete undefined, @xml._y
-        HB.addOperation(d).execute()
-        @xml._y = null
-
-      if attributes? and elements?
-        @saveOperation 'attributes', attributes
-        @saveOperation 'elements', elements
-      else if (not attributes?) and (not elements?)
-        @attributes = new types.JsonType()
-        @attributes.setMutableDefault 'immutable'
-        HB.addOperation(@attributes).execute()
-        @elements = new types.WordType()
-        @elements.parent = @
-        HB.addOperation(@elements).execute()
-      else
-        throw new Error "Either define attribute and elements both, or none of them"
-
-      if @xml?
-        @tagname = @xml.tagName
-        for i in [0...@xml.attributes.length]
-          attr = xml.attributes[i]
-          @attributes.val(attr.name, attr.value)
-        for n in @xml.childNodes
-          if n.nodeType is n.TEXT_NODE
-            word = new TextNodeType(undefined, n)
-            HB.addOperation(word).execute()
-            @elements.push word
-          else if n.nodeType is n.ELEMENT_NODE
-            element = new XmlType undefined, undefined, undefined, undefined, n
-            HB.addOperation(element).execute()
-            @elements.push element
-          else
-            throw new Error "I don't know Node-type #{n.nodeType}!!"
-        @setXmlProxy()
-      undefined
-
-    #
-    # Identifies this class.
-    # Use it in order to check whether this is an xml-type or something else.
-    #
-    type: "XmlType"
-
-    applyDelete: (op)->
-      if @insert_parent? and not @insert_parent.isDeleted()
-        @insert_parent.applyDelete op
-      else
-        @attributes.applyDelete()
-        @elements.applyDelete()
-        super
-
-    cleanup: ()->
-      super()
-
-    setXmlProxy: ()->
-      @xml._y = @
-      that = @
-
-      @elements.on 'insert', (event, op)->
-        if op.creator isnt HB.getUserId() and this is that.elements
-          newNode = op.content.val()
-          right = op.next_cl
-          while right? and right.isDeleted()
-            right = right.next_cl
-          rightNode = null
-          if right.type isnt 'Delimiter'
-            rightNode = right.val().val()
-          dont_proxy ()->
-            that.xml.insertBefore newNode, rightNode
-      @elements.on 'delete', (event, op)->
-        del_op = op.deleted_by[0]
-        if del_op? and del_op.creator isnt HB.getUserId() and this is that.elements
-          deleted = op.content.val()
-          dont_proxy ()->
-            that.xml.removeChild deleted
-
-      @attributes.on ['add', 'update'], (event, property_name, op)->
-        if op.creator isnt HB.getUserId() and this is that.attributes
-          dont_proxy ()->
-            newval = op.val().val()
-            if newval?
-              that.xml.setAttribute(property_name, op.val().val())
-            else
-              that.xml.removeAttribute(property_name)
-
-
-
-
-
-
-
-
-      ## Here are all methods that proxy the behavior of the xml
-
-      # you want to find a specific child element. Since they are carried by an Insert-Type, you want to find that Insert-Operation.
-      # @param child {DomElement} Dom element.
-      # @return {InsertType} This carries the XmlType that represents the DomElement (child). false if i couldn't find it.
-      #
-      findNode = (child)->
-        if not child?
-          throw new Error "you must specify a parameter!"
-        child = child._y
-        elem = that.elements.beginning.next_cl
-        while elem.type isnt 'Delimiter' and elem.content isnt child
-          elem = elem.next_cl
-        if elem.type is 'Delimiter'
-          false
-        else
-          elem
-
-      insertBefore = (insertedNode_s, adjacentNode)->
-        next = null
-        if adjacentNode?
-          next = findNode adjacentNode
-        prev = null
-        if next
-          prev = next.prev_cl
-        else
-          prev = @_y.elements.end.prev_cl
-          while prev.isDeleted()
-            prev = prev.prev_cl
-        inserted_nodes = null
-        if insertedNode_s.nodeType is insertedNode_s.DOCUMENT_FRAGMENT_NODE
-          child = insertedNode_s.lastChild
-          while child?
-            element = new XmlType undefined, undefined, undefined, undefined, child
-            HB.addOperation(element).execute()
-            that.elements.insertAfter prev, element
-            child = child.previousSibling
-        else
-          element = new XmlType undefined, undefined, undefined, undefined, insertedNode_s
-          HB.addOperation(element).execute()
-          that.elements.insertAfter prev, element
-
-      @xml._proxy 'insertBefore', insertBefore
-      @xml._proxy 'appendChild', insertBefore
-      @xml._proxy 'removeAttribute', (name)->
-        that.attributes.val(name, undefined)
-      @xml._proxy 'setAttribute', (name, value)->
-        that.attributes.val name, value
-
-      renewClassList = (newclass)->
-        dont_do_it = false
-        if newclass?
-          for elem in this
-            if newclass is elem
-              dont_do_it = true
-        value = Array.prototype.join.call this, " "
-        if newclass? and not dont_do_it
-          value += " "+newclass
-        that.attributes.val('class', value )
-      _proxy.call @xml.classList, 'add', renewClassList
-      _proxy.call @xml.classList, 'remove', renewClassList
-      @xml.__defineSetter__ 'className', (val)->
-        @setAttribute('class', val)
-      @xml.__defineGetter__ 'className', ()->
-        that.attributes.val('class')
-      @xml.__defineSetter__ 'textContent', (val)->
-        # remove all nodes
-        elem = that.xml.firstChild
-        while elem?
-          remove = elem
-          elem = elem.nextSibling
-          that.xml.removeChild remove
-
-        # insert word content
-        if val isnt ""
-          text_node = document.createTextNode val
-          that.xml.appendChild text_node
-
-      removeChild = (node)->
-        elem = findNode node
-        if not elem
-          throw new Error "You are only allowed to delete existing (direct) child elements!"
-        d = new types.Delete undefined, elem
-        HB.addOperation(d).execute()
-        node._y = null
-      @xml._proxy 'removeChild', removeChild
-      @xml._proxy 'replaceChild', (insertedNode, replacedNode)->
-        insertBefore.call this, insertedNode, replacedNode
-        removeChild.call this, replacedNode
-
-
-
-    val: (enforce = false)->
-      if document?
-        if (not @xml?) or enforce
-          @xml = document.createElement @tagname
-
-          attr = @attributes.val()
-          for attr_name, value of attr
-            if value?
-              a = document.createAttribute attr_name
-              a.value = value
-              @xml.setAttributeNode a
-
-          e = @elements.beginning.next_cl
-          while e.type isnt "Delimiter"
-            n = e.content
-            if not e.isDeleted() and e.content? # TODO: how can this happen?  Probably because listeners
-              if n.type is "XmlType"
-                @xml.appendChild n.val(enforce)
-              else if n.type is "TextNodeType"
-                text_node = n.val()
-                @xml.appendChild text_node
-              else
-                throw new Error "Internal structure cannot be transformed to dom"
-            e = e.next_cl
-        @setXmlProxy()
-        @xml
-
-
-    execute: ()->
-      super()
-    ###
-      if not @validateSavedOperations()
-        return false
-      else
-
-        return true
-    ###
-
-    #
-    # Get the parent of this JsonType.
-    # @return {XmlType}
-    #
-    getParent: ()->
-      @parent
-
-    #
-    # @private
-    #
-    # Convert all relevant information of this operation to the json-format.
-    # This result can be send to other clients.
-    #
-    _encode: ()->
-      json =
-        {
-          'type' : @type
-          'attributes' : @attributes.getUid()
-          'elements' : @elements.getUid()
-          'tagname' : @tagname
-          'uid' : @getUid()
-        }
-      json
-
-  parser['XmlType'] = (json)->
-    {
-      'uid' : uid
-      'attributes' : attributes
-      'elements' : elements
-      'tagname' : tagname
-    } = json
-
-    new XmlType uid, tagname, attributes, elements, undefined
-
-#
-  # @nodoc
-  # Defines an object that is cannot be changed. You can use this to set an immutable string, or a number.
-  #
-  class TextNodeType extends types.ImmutableObject
-
-    #
-    # @param {Object} uid A unique identifier. If uid is undefined, a new uid will be created.
-    # @param {Object} content
-    #
-    constructor: (uid, content)->
-      if content._y?
-        d = new types.Delete undefined, content._y
-        HB.addOperation(d).execute()
-        content._y = null
-      content._y = @
-      super uid, content
-
-    applyDelete: (op)->
-      if @insert_parent? and not @insert_parent.isDeleted()
-        @insert_parent.applyDelete op
-      else
-        super
-
-
-    type: "TextNodeType"
-
-    #
-    # Encode this operation in such a way that it can be parsed by remote peers.
-    #
-    _encode: ()->
-      json = {
-        'type': @type
-        'uid' : @getUid()
-        'content' : @content.textContent
-      }
-      json
-
-  parser['TextNodeType'] = (json)->
-    {
-      'uid' : uid
-      'content' : content
-    } = json
-    textnode = document.createTextNode content
-    new TextNodeType uid, textnode
-
-  types['XmlType'] = XmlType
-
-  json_types
-###

package.json

@@ -1,66 +1,92 @@
 {
   "name": "yjs",
-  "version": "0.3.0",
-  "description": "A Framework that enables Real-Time Collaboration on arbitrary data structures.",
-  "main": "./build/node/y.js",
+  "version": "13.6.0-2",
+  "description": "Shared Editing Library",
+  "main": "./dist/yjs.cjs",
+  "module": "./dist/yjs.mjs",
+  "types": "./dist/src/index.d.ts",
+  "type": "module",
+  "sideEffects": false,
+  "funding": {
+    "type": "GitHub Sponsors ❤",
+    "url": "https://github.com/sponsors/dmonad"
+  },
   "scripts": {
-    "test": "./node_modules/.bin/gulp test"
+    "test": "npm run dist && node ./dist/tests.cjs --repetition-time 50",
+    "test-extensive": "npm run lint && npm run dist && node ./dist/tests.cjs --production --repetition-time 10000",
+    "dist": "rm -rf dist && rollup -c && tsc",
+    "watch": "rollup -wc",
+    "lint": "markdownlint README.md && standard && tsc",
+    "docs": "rm -rf docs; jsdoc --configure ./.jsdoc.json --verbose --readme ./README.md --package ./package.json || true",
+    "serve-docs": "npm run docs && http-server ./docs/",
+    "preversion": "npm run lint && PRODUCTION=1 npm run dist && npm run docs && test -e dist/src/index.d.ts && test -e dist/yjs.cjs && test -e dist/yjs.cjs",
+    "debug": "concurrently 'http-server -o test.html' 'npm run watch'",
+    "trace-deopt": "clear && rollup -c  && node --trace-deopt dist/test.cjs",
+    "trace-opt": "clear && rollup -c  && node --trace-opt dist/test.cjs",
+    "postinstall": "node ./sponsor-y.js"
+  },
+  "exports": {
+    ".": {
+      "import": "./dist/yjs.mjs",
+      "require": "./dist/yjs.cjs"
+    },
+    "./src/index.js": "./src/index.js",
+    "./tests/testHelper.js": "./tests/testHelper.js",
+    "./testHelper": "./dist/testHelper.mjs",
+    "./package.json": "./package.json"
+  },
+  "files": [
+    "dist/yjs.*",
+    "dist/src",
+    "src",
+    "tests/testHelper.js",
+    "dist/testHelper.mjs",
+    "sponsor-y.js"
+  ],
+  "dictionaries": {
+    "test": "tests"
+  },
+  "standard": {
+    "ignore": [
+      "/dist",
+      "/node_modules",
+      "/docs"
+    ]
   },
   "repository": {
     "type": "git",
-    "url": "https://github.com/rwth-acis/yjs"
+    "url": "https://github.com/yjs/yjs.git"
   },
   "keywords": [
-    "OT",
-    "collaboration",
-    "Yata",
-    "synchronization",
-    "ShareJS",
-    "Coweb",
-    "concurrency"
+    "Yjs",
+    "CRDT",
+    "offline",
+    "offline-first",
+    "shared-editing",
+    "concurrency",
+    "collaboration"
   ],
   "author": "Kevin Jahns",
-  "email": "kevin.jahns@rwth-aachen.de",
+  "email": "kevin.jahns@protonmail.com",
   "license": "MIT",
   "bugs": {
-    "url": "https://github.com/rwth-acis/yjs/issues"
+    "url": "https://github.com/yjs/yjs/issues"
   },
-  "homepage": "https://dadamonad.github.io/yjs/",
+  "homepage": "https://docs.yjs.dev",
   "dependencies": {
+    "lib0": "^0.2.43"
   },
   "devDependencies": {
-    "codo": "^2.0.9",
-    "underscore": "^1.6.0",
-    "chai": "^1.9.1",
-    "codo": "^2.0.9",
-    "coffee-errors": "~0.8.6",
-    "coffee-script": "^1.7.1",
-    "coffeeify": "^0.6.0",
-    "gulp": "^3.8.7",
-    "gulp-browserify": "^0.5.0",
-    "gulp-cached": "^1.0.1",
-    "gulp-coffee": "^2.1.1",
-    "gulp-coffeeify": "^0.1.2",
-    "gulp-coffeelint": "^0.3.3",
-    "gulp-concat": "^2.3.4",
-    "gulp-copy": "0.0.2",
-    "gulp-debug": "^1.0.0",
-    "gulp-git": "^0.5.0",
-    "gulp-if": "^1.2.4",
-    "gulp-ignore": "^1.2.0",
-    "gulp-ljs": "^0.1.1",
-    "gulp-mocha": "^0.5.2",
-    "gulp-mocha-phantomjs": "^0.5.0",
-    "gulp-plumber": "^0.6.6",
-    "gulp-rename": "^1.2.0",
-    "gulp-rimraf": "^0.1.0",
-    "gulp-run": "^1.6.3",
-    "gulp-sourcemaps": "^1.1.1",
-    "gulp-uglify": "^0.3.1",
-    "gulp-watch": "^3.0.0",
-    "jquery": "^2.1.1",
-    "mocha": "^1.21.4",
-    "sinon": "^1.10.2",
-    "sinon-chai": "^2.5.0"
+    "@rollup/plugin-commonjs": "^17.0.0",
+    "@rollup/plugin-node-resolve": "^11.2.1",
+    "concurrently": "^3.6.1",
+    "http-server": "^0.12.3",
+    "jsdoc": "^3.6.7",
+    "markdownlint-cli": "^0.23.2",
+    "rollup": "^2.60.0",
+    "standard": "^16.0.4",
+    "tui-jsdoc-template": "^1.2.2",
+    "typescript": "^4.4.4",
+    "y-protocols": "^1.0.5"
   }
 }

rollup.config.js

@@ -0,0 +1,111 @@
+import nodeResolve from '@rollup/plugin-node-resolve'
+import commonjs from '@rollup/plugin-commonjs'
+
+const localImports = process.env.LOCALIMPORTS
+
+const customModules = new Set([
+  'y-websocket',
+  'y-codemirror',
+  'y-ace',
+  'y-textarea',
+  'y-quill',
+  'y-dom',
+  'y-prosemirror'
+])
+/**
+ * @type {Set<any>}
+ */
+const customLibModules = new Set([
+  'lib0',
+  'y-protocols'
+])
+const debugResolve = {
+  resolveId (importee) {
+    if (importee === 'yjs') {
+      return `${process.cwd()}/src/index.js`
+    }
+    if (localImports) {
+      if (customModules.has(importee.split('/')[0])) {
+        return `${process.cwd()}/../${importee}/src/${importee}.js`
+      }
+      if (customLibModules.has(importee.split('/')[0])) {
+        return `${process.cwd()}/../${importee}`
+      }
+    }
+    return null
+  }
+}
+
+export default [{
+  input: './src/index.js',
+  output: {
+    name: 'Y',
+    file: 'dist/yjs.cjs',
+    format: 'cjs',
+    sourcemap: true,
+    paths: path => {
+      if (/^lib0\//.test(path)) {
+        return `lib0/dist/${path.slice(5)}.cjs`
+      }
+      return path
+    }
+  },
+  external: id => /^lib0\//.test(id)
+}, {
+  input: './src/index.js',
+  output: {
+    name: 'Y',
+    file: 'dist/yjs.mjs',
+    format: 'esm',
+    sourcemap: true
+  },
+  external: id => /^lib0\//.test(id)
+}, {
+  input: './tests/testHelper.js',
+  output: {
+    name: 'Y',
+    file: 'dist/testHelper.mjs',
+    format: 'esm',
+    sourcemap: true
+  },
+  external: id => /^lib0\//.test(id) || id === 'yjs',
+  plugins: [{
+    resolveId (importee) {
+      if (importee === '../src/index.js') {
+        return 'yjs'
+      }
+      return null
+    }
+  }]
+}, {
+  input: './tests/index.js',
+  output: {
+    name: 'test',
+    file: 'dist/tests.js',
+    format: 'iife',
+    sourcemap: true
+  },
+  plugins: [
+    debugResolve,
+    nodeResolve({
+      mainFields: ['module', 'browser', 'main']
+    }),
+    commonjs()
+  ]
+}, {
+  input: './tests/index.js',
+  output: {
+    name: 'test',
+    file: 'dist/tests.cjs',
+    format: 'cjs',
+    sourcemap: true
+  },
+  plugins: [
+    debugResolve,
+    nodeResolve({
+      mainFields: ['module', 'main']
+    }),
+    commonjs()
+  ],
+  external: ['isomorphic.js']
+}]

sponsor-y.js

@@ -0,0 +1,12 @@
+
+try {
+  const log = require('lib0/dist/logging.cjs')
+
+  log.print()
+  log.print(log.BOLD, log.GREEN, log.BOLD, 'Thank you for using Yjs ', log.RED, '❤\n')
+  log.print(
+    log.GREY,
+    'The project has grown considerably in the past year. Too much for me to maintain\nin my spare time. Several companies built their products with Yjs.\nYet, this project receives very little funding. Yjs is far from done. I want to\ncreate more awesome extensions and work on the growing number of open issues.\n', log.BOLD, 'Dear user, the future of this project entirely depends on you.\n')
+  log.print(log.BLUE, log.BOLD, 'Please start funding the project now: https://github.com/sponsors/dmonad \n')
+  log.print(log.GREY, '(This message will be removed when I achieved my funding goal)\n\n')
+} catch (e) { }

src/index.js

@@ -0,0 +1,111 @@
+/** eslint-env browser */
+
+export {
+  Doc,
+  Transaction,
+  YArray as Array,
+  YMap as Map,
+  YText as Text,
+  YXmlText as XmlText,
+  YXmlHook as XmlHook,
+  YXmlElement as XmlElement,
+  YXmlFragment as XmlFragment,
+  YXmlEvent,
+  YMapEvent,
+  YArrayEvent,
+  YTextEvent,
+  YEvent,
+  Item,
+  AbstractStruct,
+  GC,
+  ContentBinary,
+  ContentDeleted,
+  ContentEmbed,
+  ContentFormat,
+  ContentJSON,
+  ContentAny,
+  ContentString,
+  ContentType,
+  AbstractType,
+  getTypeChildren,
+  createRelativePositionFromTypeIndex,
+  createRelativePositionFromJSON,
+  createAbsolutePositionFromRelativePosition,
+  compareRelativePositions,
+  AbsolutePosition,
+  RelativePosition,
+  ID,
+  createID,
+  compareIDs,
+  getState,
+  Snapshot,
+  createSnapshot,
+  createDeleteSet,
+  createDeleteSetFromStructStore,
+  cleanupYTextFormatting,
+  snapshot,
+  emptySnapshot,
+  findRootTypeKey,
+  findIndexSS,
+  getItem,
+  typeListToArraySnapshot,
+  typeMapGetSnapshot,
+  createDocFromSnapshot,
+  iterateDeletedStructs,
+  applyUpdate,
+  applyUpdateV2,
+  readUpdate,
+  readUpdateV2,
+  encodeStateAsUpdate,
+  encodeStateAsUpdateV2,
+  encodeStateVector,
+  UndoManager,
+  decodeSnapshot,
+  encodeSnapshot,
+  decodeSnapshotV2,
+  encodeSnapshotV2,
+  decodeStateVector,
+  logUpdate,
+  logUpdateV2,
+  relativePositionToJSON,
+  isDeleted,
+  isParentOf,
+  equalSnapshots,
+  PermanentUserData, // @TODO experimental
+  tryGc,
+  transact,
+  AbstractConnector,
+  logType,
+  mergeUpdates,
+  mergeUpdatesV2,
+  parseUpdateMeta,
+  parseUpdateMetaV2,
+  encodeStateVectorFromUpdate,
+  encodeStateVectorFromUpdateV2,
+  encodeRelativePosition,
+  decodeRelativePosition,
+  diffUpdate,
+  diffUpdateV2
+} from './internals.js'
+
+const glo = /** @type {any} */ (typeof window !== 'undefined'
+  ? window
+  : typeof global !== 'undefined' ? global : {})
+const importIdentifier = '__ $YJS$ __'
+
+if (glo[importIdentifier] === true) {
+  /**
+   * Dear reader of this warning message. Please take this seriously.
+   *
+   * If you see this message, please make sure that you only import one version of Yjs. In many cases,
+   * your package manager installs two versions of Yjs that are used by different packages within your project.
+   * Another reason for this message is that some parts of your project use the commonjs version of Yjs
+   * and others use the EcmaScript version of Yjs.
+   *
+   * This often leads to issues that are hard to debug. We often need to perform constructor checks,
+   * e.g. `struct instanceof GC`. If you imported different versions of Yjs, it is impossible for us to
+   * do the constructor checks anymore - which might break the CRDT algorithm.
+   */
+  console.warn('Yjs was already imported. Importing different versions of Yjs often leads to issues.')
+}
+glo[importIdentifier] = true

src/internals.js

@@ -0,0 +1,45 @@
+
+export * from './utils/AbstractConnector.js'
+export * from './utils/DeleteSet.js'
+export * from './utils/Doc.js'
+export * from './utils/UpdateDecoder.js'
+export * from './utils/UpdateEncoder.js'
+export * from './utils/encoding.js'
+export * from './utils/EventHandler.js'
+export * from './utils/ID.js'
+export * from './utils/isParentOf.js'
+export * from './utils/ListIterator.js'
+export * from './utils/logging.js'
+export * from './utils/PermanentUserData.js'
+export * from './utils/RelativePosition.js'
+export * from './utils/Snapshot.js'
+export * from './utils/StructStore.js'
+export * from './utils/Transaction.js'
+export * from './utils/UndoManager.js'
+export * from './utils/updates.js'
+export * from './utils/YEvent.js'
+
+export * from './types/AbstractType.js'
+export * from './types/YArray.js'
+export * from './types/YMap.js'
+export * from './types/YText.js'
+export * from './types/YXmlFragment.js'
+export * from './types/YXmlElement.js'
+export * from './types/YXmlEvent.js'
+export * from './types/YXmlHook.js'
+export * from './types/YXmlText.js'
+
+export * from './structs/AbstractStruct.js'
+export * from './structs/GC.js'
+export * from './structs/ContentBinary.js'
+export * from './structs/ContentDeleted.js'
+export * from './structs/ContentDoc.js'
+export * from './structs/ContentEmbed.js'
+export * from './structs/ContentFormat.js'
+export * from './structs/ContentJSON.js'
+export * from './structs/ContentAny.js'
+export * from './structs/ContentString.js'
+export * from './structs/ContentMove.js'
+export * from './structs/ContentType.js'
+export * from './structs/Item.js'
+export * from './structs/Skip.js'

src/structs/AbstractStruct.js

@@ -0,0 +1,52 @@
+
+import {
+  UpdateEncoderV1, UpdateEncoderV2, ID, Transaction // eslint-disable-line
+} from '../internals.js'
+
+import * as error from 'lib0/error'
+
+export class AbstractStruct {
+  /**
+   * @param {ID} id
+   * @param {number} length
+   */
+  constructor (id, length) {
+    this.id = id
+    this.length = length
+  }
+
+  /**
+   * @type {boolean}
+   */
+  get deleted () {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * Merge this struct with the item to the right.
+   * This method is already assuming that `this.id.clock + this.length === this.id.clock`.
+   * Also this method does *not* remove right from StructStore!
+   * @param {AbstractStruct} right
+   * @return {boolean} wether this merged with right
+   */
+  mergeWith (right) {
+    return false
+  }
+
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder The encoder to write data to.
+   * @param {number} offset
+   * @param {number} encodingRef
+   */
+  write (encoder, offset, encodingRef) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {number} offset
+   */
+  integrate (transaction, offset) {
+    throw error.methodUnimplemented()
+  }
+}

src/structs/ContentAny.js

@@ -0,0 +1,108 @@
+import {
+  UpdateEncoderV1, UpdateEncoderV2, UpdateDecoderV1, UpdateDecoderV2, Transaction, Item, StructStore // eslint-disable-line
+} from '../internals.js'
+
+export class ContentAny {
+  /**
+   * @param {Array<any>} arr
+   */
+  constructor (arr) {
+    /**
+     * @type {Array<any>}
+     */
+    this.arr = arr
+  }
+
+  /**
+   * @return {number}
+   */
+  getLength () {
+    return this.arr.length
+  }
+
+  /**
+   * @return {Array<any>}
+   */
+  getContent () {
+    return this.arr
+  }
+
+  /**
+   * @return {boolean}
+   */
+  isCountable () {
+    return true
+  }
+
+  /**
+   * @return {ContentAny}
+   */
+  copy () {
+    return new ContentAny(this.arr)
+  }
+
+  /**
+   * @param {number} offset
+   * @return {ContentAny}
+   */
+  splice (offset) {
+    const right = new ContentAny(this.arr.slice(offset))
+    this.arr = this.arr.slice(0, offset)
+    return right
+  }
+
+  /**
+   * @param {ContentAny} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    this.arr = this.arr.concat(right.arr)
+    return true
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  integrate (transaction, item) {}
+  /**
+   * @param {Transaction} transaction
+   */
+  delete (transaction) {}
+  /**
+   * @param {StructStore} store
+   */
+  gc (store) {}
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    const len = this.arr.length
+    encoder.writeLen(len - offset)
+    for (let i = offset; i < len; i++) {
+      const c = this.arr[i]
+      encoder.writeAny(c)
+    }
+  }
+
+  /**
+   * @return {number}
+   */
+  getRef () {
+    return 8
+  }
+}
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {ContentAny}
+ */
+export const readContentAny = decoder => {
+  const len = decoder.readLen()
+  const cs = []
+  for (let i = 0; i < len; i++) {
+    cs.push(decoder.readAny())
+  }
+  return new ContentAny(cs)
+}

src/structs/ContentBinary.js

@@ -0,0 +1,92 @@
+import {
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, StructStore, Item, Transaction // eslint-disable-line
+} from '../internals.js'
+
+import * as error from 'lib0/error'
+
+export class ContentBinary {
+  /**
+   * @param {Uint8Array} content
+   */
+  constructor (content) {
+    this.content = content
+  }
+
+  /**
+   * @return {number}
+   */
+  getLength () {
+    return 1
+  }
+
+  /**
+   * @return {Array<any>}
+   */
+  getContent () {
+    return [this.content]
+  }
+
+  /**
+   * @return {boolean}
+   */
+  isCountable () {
+    return true
+  }
+
+  /**
+   * @return {ContentBinary}
+   */
+  copy () {
+    return new ContentBinary(this.content)
+  }
+
+  /**
+   * @param {number} offset
+   * @return {ContentBinary}
+   */
+  splice (offset) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {ContentBinary} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    return false
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  integrate (transaction, item) {}
+  /**
+   * @param {Transaction} transaction
+   */
+  delete (transaction) {}
+  /**
+   * @param {StructStore} store
+   */
+  gc (store) {}
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    encoder.writeBuf(this.content)
+  }
+
+  /**
+   * @return {number}
+   */
+  getRef () {
+    return 3
+  }
+}
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2 } decoder
+ * @return {ContentBinary}
+ */
+export const readContentBinary = decoder => new ContentBinary(decoder.readBuf())

src/structs/ContentDeleted.js

@@ -0,0 +1,101 @@
+
+import {
+  addToDeleteSet,
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, StructStore, Item, Transaction // eslint-disable-line
+} from '../internals.js'
+
+export class ContentDeleted {
+  /**
+   * @param {number} len
+   */
+  constructor (len) {
+    this.len = len
+  }
+
+  /**
+   * @return {number}
+   */
+  getLength () {
+    return this.len
+  }
+
+  /**
+   * @return {Array<any>}
+   */
+  getContent () {
+    return []
+  }
+
+  /**
+   * @return {boolean}
+   */
+  isCountable () {
+    return false
+  }
+
+  /**
+   * @return {ContentDeleted}
+   */
+  copy () {
+    return new ContentDeleted(this.len)
+  }
+
+  /**
+   * @param {number} offset
+   * @return {ContentDeleted}
+   */
+  splice (offset) {
+    const right = new ContentDeleted(this.len - offset)
+    this.len = offset
+    return right
+  }
+
+  /**
+   * @param {ContentDeleted} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    this.len += right.len
+    return true
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  integrate (transaction, item) {
+    addToDeleteSet(transaction.deleteSet, item.id.client, item.id.clock, this.len)
+    item.markDeleted()
+  }
+
+  /**
+   * @param {Transaction} transaction
+   */
+  delete (transaction) {}
+  /**
+   * @param {StructStore} store
+   */
+  gc (store) {}
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    encoder.writeLen(this.len - offset)
+  }
+
+  /**
+   * @return {number}
+   */
+  getRef () {
+    return 1
+  }
+}
+
+/**
+ * @private
+ *
+ * @param {UpdateDecoderV1 | UpdateDecoderV2 } decoder
+ * @return {ContentDeleted}
+ */
+export const readContentDeleted = decoder => new ContentDeleted(decoder.readLen())

src/structs/ContentDoc.js

@@ -0,0 +1,141 @@
+
+import {
+  Doc, UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, StructStore, Transaction, Item // eslint-disable-line
+} from '../internals.js'
+
+import * as error from 'lib0/error'
+
+/**
+ * @param {string} guid
+ * @param {Object<string, any>} opts
+ */
+const createDocFromOpts = (guid, opts) => new Doc({ guid, ...opts, shouldLoad: opts.shouldLoad || opts.autoLoad || false })
+
+/**
+ * @private
+ */
+export class ContentDoc {
+  /**
+   * @param {Doc} doc
+   */
+  constructor (doc) {
+    if (doc._item) {
+      console.error('This document was already integrated as a sub-document. You should create a second instance instead with the same guid.')
+    }
+    /**
+     * @type {Doc}
+     */
+    this.doc = doc
+    /**
+     * @type {any}
+     */
+    const opts = {}
+    this.opts = opts
+    if (!doc.gc) {
+      opts.gc = false
+    }
+    if (doc.autoLoad) {
+      opts.autoLoad = true
+    }
+    if (doc.meta !== null) {
+      opts.meta = doc.meta
+    }
+  }
+
+  /**
+   * @return {number}
+   */
+  getLength () {
+    return 1
+  }
+
+  /**
+   * @return {Array<any>}
+   */
+  getContent () {
+    return [this.doc]
+  }
+
+  /**
+   * @return {boolean}
+   */
+  isCountable () {
+    return true
+  }
+
+  /**
+   * @return {ContentDoc}
+   */
+  copy () {
+    return new ContentDoc(createDocFromOpts(this.doc.guid, this.opts))
+  }
+
+  /**
+   * @param {number} offset
+   * @return {ContentDoc}
+   */
+  splice (offset) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {ContentDoc} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    return false
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  integrate (transaction, item) {
+    // this needs to be reflected in doc.destroy as well
+    this.doc._item = item
+    transaction.subdocsAdded.add(this.doc)
+    if (this.doc.shouldLoad) {
+      transaction.subdocsLoaded.add(this.doc)
+    }
+  }
+
+  /**
+   * @param {Transaction} transaction
+   */
+  delete (transaction) {
+    if (transaction.subdocsAdded.has(this.doc)) {
+      transaction.subdocsAdded.delete(this.doc)
+    } else {
+      transaction.subdocsRemoved.add(this.doc)
+    }
+  }
+
+  /**
+   * @param {StructStore} store
+   */
+  gc (store) { }
+
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    encoder.writeString(this.doc.guid)
+    encoder.writeAny(this.opts)
+  }
+
+  /**
+   * @return {number}
+   */
+  getRef () {
+    return 9
+  }
+}
+
+/**
+ * @private
+ *
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {ContentDoc}
+ */
+export const readContentDoc = decoder => new ContentDoc(createDocFromOpts(decoder.readString(), decoder.readAny()))

src/structs/ContentEmbed.js

@@ -0,0 +1,98 @@
+
+import {
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, StructStore, Item, Transaction // eslint-disable-line
+} from '../internals.js'
+
+import * as error from 'lib0/error'
+
+/**
+ * @private
+ */
+export class ContentEmbed {
+  /**
+   * @param {Object} embed
+   */
+  constructor (embed) {
+    this.embed = embed
+  }
+
+  /**
+   * @return {number}
+   */
+  getLength () {
+    return 1
+  }
+
+  /**
+   * @return {Array<any>}
+   */
+  getContent () {
+    return [this.embed]
+  }
+
+  /**
+   * @return {boolean}
+   */
+  isCountable () {
+    return true
+  }
+
+  /**
+   * @return {ContentEmbed}
+   */
+  copy () {
+    return new ContentEmbed(this.embed)
+  }
+
+  /**
+   * @param {number} offset
+   * @return {ContentEmbed}
+   */
+  splice (offset) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {ContentEmbed} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    return false
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  integrate (transaction, item) {}
+  /**
+   * @param {Transaction} transaction
+   */
+  delete (transaction) {}
+  /**
+   * @param {StructStore} store
+   */
+  gc (store) {}
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    encoder.writeJSON(this.embed)
+  }
+
+  /**
+   * @return {number}
+   */
+  getRef () {
+    return 5
+  }
+}
+
+/**
+ * @private
+ *
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {ContentEmbed}
+ */
+export const readContentEmbed = decoder => new ContentEmbed(decoder.readJSON())

src/structs/ContentFormat.js

@@ -0,0 +1,103 @@
+
+import {
+  AbstractType, UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, Item, StructStore, Transaction // eslint-disable-line
+} from '../internals.js'
+
+import * as error from 'lib0/error'
+
+/**
+ * @private
+ */
+export class ContentFormat {
+  /**
+   * @param {string} key
+   * @param {Object} value
+   */
+  constructor (key, value) {
+    this.key = key
+    this.value = value
+  }
+
+  /**
+   * @return {number}
+   */
+  getLength () {
+    return 1
+  }
+
+  /**
+   * @return {Array<any>}
+   */
+  getContent () {
+    return []
+  }
+
+  /**
+   * @return {boolean}
+   */
+  isCountable () {
+    return false
+  }
+
+  /**
+   * @return {ContentFormat}
+   */
+  copy () {
+    return new ContentFormat(this.key, this.value)
+  }
+
+  /**
+   * @param {number} offset
+   * @return {ContentFormat}
+   */
+  splice (offset) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {ContentFormat} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    return false
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  integrate (transaction, item) {
+    // @todo searchmarker are currently unsupported for rich text documents
+    /** @type {AbstractType<any>} */ (item.parent)._searchMarker = null
+  }
+
+  /**
+   * @param {Transaction} transaction
+   */
+  delete (transaction) {}
+  /**
+   * @param {StructStore} store
+   */
+  gc (store) {}
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    encoder.writeKey(this.key)
+    encoder.writeJSON(this.value)
+  }
+
+  /**
+   * @return {number}
+   */
+  getRef () {
+    return 6
+  }
+}
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {ContentFormat}
+ */
+export const readContentFormat = decoder => new ContentFormat(decoder.readString(), decoder.readJSON())

src/structs/ContentJSON.js

@@ -0,0 +1,118 @@
+import {
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, Transaction, Item, StructStore // eslint-disable-line
+} from '../internals.js'
+
+/**
+ * @private
+ */
+export class ContentJSON {
+  /**
+   * @param {Array<any>} arr
+   */
+  constructor (arr) {
+    /**
+     * @type {Array<any>}
+     */
+    this.arr = arr
+  }
+
+  /**
+   * @return {number}
+   */
+  getLength () {
+    return this.arr.length
+  }
+
+  /**
+   * @return {Array<any>}
+   */
+  getContent () {
+    return this.arr
+  }
+
+  /**
+   * @return {boolean}
+   */
+  isCountable () {
+    return true
+  }
+
+  /**
+   * @return {ContentJSON}
+   */
+  copy () {
+    return new ContentJSON(this.arr)
+  }
+
+  /**
+   * @param {number} offset
+   * @return {ContentJSON}
+   */
+  splice (offset) {
+    const right = new ContentJSON(this.arr.slice(offset))
+    this.arr = this.arr.slice(0, offset)
+    return right
+  }
+
+  /**
+   * @param {ContentJSON} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    this.arr = this.arr.concat(right.arr)
+    return true
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  integrate (transaction, item) {}
+  /**
+   * @param {Transaction} transaction
+   */
+  delete (transaction) {}
+  /**
+   * @param {StructStore} store
+   */
+  gc (store) {}
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    const len = this.arr.length
+    encoder.writeLen(len - offset)
+    for (let i = offset; i < len; i++) {
+      const c = this.arr[i]
+      encoder.writeString(c === undefined ? 'undefined' : JSON.stringify(c))
+    }
+  }
+
+  /**
+   * @return {number}
+   */
+  getRef () {
+    return 2
+  }
+}
+
+/**
+ * @private
+ *
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {ContentJSON}
+ */
+export const readContentJSON = decoder => {
+  const len = decoder.readLen()
+  const cs = []
+  for (let i = 0; i < len; i++) {
+    const c = decoder.readString()
+    if (c === 'undefined') {
+      cs.push(undefined)
+    } else {
+      cs.push(JSON.parse(c))
+    }
+  }
+  return new ContentJSON(cs)
+}

src/structs/ContentMove.js

@@ -0,0 +1,286 @@
+
+import * as error from 'lib0/error'
+import * as decoding from 'lib0/decoding'
+import * as encoding from 'lib0/encoding'
+import * as math from 'lib0/math'
+import {
+  AbstractType, ContentType, RelativePosition, UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, Transaction, Item, StructStore, getItem, getItemCleanStart, getItemCleanEnd // eslint-disable-line
+} from '../internals.js'
+import { decodeRelativePosition, encodeRelativePosition } from 'yjs'
+
+/**
+ * @param {ContentMove} moved
+ * @param {Transaction} tr
+ * @return {{ start: Item, end: Item | null }} $start (inclusive) is the beginning and $end (exclusive) is the end of the moved area
+ */
+export const getMovedCoords = (moved, tr) => {
+  let start // this (inclusive) is the beginning of the moved area
+  let end // this (exclusive) is the first item after start that is not part of the moved area
+  if (moved.start.item) {
+    if (moved.start.assoc < 0) {
+      start = getItemCleanEnd(tr, moved.start.item)
+      start = start.right
+    } else {
+      start = getItemCleanStart(tr, moved.start.item)
+    }
+  } else if (moved.start.tname != null) {
+    start = tr.doc.get(moved.start.tname)._start
+  } else if (moved.start.type) {
+    start = /** @type {ContentType} */ (getItem(tr.doc.store, moved.start.type).content).type._start
+  } else {
+    error.unexpectedCase()
+  }
+  if (moved.end.item) {
+    if (moved.end.assoc < 0) {
+      end = getItemCleanEnd(tr, moved.end.item)
+      end = end.right
+    } else {
+      end = getItemCleanStart(tr, moved.end.item)
+    }
+  } else {
+    end = null
+  }
+  return { start: /** @type {Item} */ (start), end }
+}
+
+/**
+ * @todo remove this if not needed
+ *
+ * @param {ContentMove} moved
+ * @param {Item} movedItem
+ * @param {Transaction} tr
+ * @param {function(Item):void} cb
+ */
+export const iterateMoved = (moved, movedItem, tr, cb) => {
+  /**
+   * @type {{ start: Item | null, end: Item | null }}
+   */
+  let { start, end } = getMovedCoords(moved, tr)
+  while (start !== end && start != null) {
+    if (!start.deleted) {
+      if (start.moved === movedItem) {
+        if (start.content.constructor === ContentMove) {
+          iterateMoved(start.content, start, tr, cb)
+        } else {
+          cb(start)
+        }
+      }
+    }
+    start = start.right
+  }
+}
+
+/**
+ * @param {ContentMove} moved
+ * @param {Item} movedItem
+ * @param {Set<Item>} trackedMovedItems
+ * @param {Transaction} tr
+ * @return {boolean} true if there is a loop
+ */
+export const findMoveLoop = (moved, movedItem, trackedMovedItems, tr) => {
+  if (trackedMovedItems.has(movedItem)) {
+    return true
+  }
+  trackedMovedItems.add(movedItem)
+  /**
+   * @type {{ start: Item | null, end: Item | null }}
+   */
+  let { start, end } = getMovedCoords(moved, tr)
+  while (start !== end && start != null) {
+    if (start.deleted && start.moved === movedItem && start.content.constructor === ContentMove) {
+      if (findMoveLoop(start.content, start, trackedMovedItems, tr)) {
+        return true
+      }
+    }
+    start = start.right
+  }
+  return false
+}
+
+/**
+ * @private
+ */
+export class ContentMove {
+  /**
+   * @param {RelativePosition} start
+   * @param {RelativePosition} end
+   * @param {number} priority if we want to move content that is already moved, we need to assign a higher priority to this move operation.
+   */
+  constructor (start, end, priority) {
+    this.start = start
+    this.end = end
+    this.priority = priority
+    /**
+     * We store which Items+ContentMove we override. Once we delete
+     * this ContentMove, we need to re-integrate the overridden items.
+     *
+     * This representation can be improved if we ever run into memory issues because of too many overrides.
+     * Ideally, we should probably just re-iterate the document and re-integrate all moved items.
+     * This is fast enough and reduces memory footprint significantly.
+     *
+     * @type {Set<Item>}
+     */
+    this.overrides = new Set()
+  }
+
+  /**
+   * @return {number}
+   */
+  getLength () {
+    return 1
+  }
+
+  /**
+   * @return {Array<any>}
+   */
+  getContent () {
+    return [null]
+  }
+
+  /**
+   * @return {boolean}
+   */
+  isCountable () {
+    return false
+  }
+
+  /**
+   * @return {ContentMove}
+   */
+  copy () {
+    return new ContentMove(this.start, this.end, this.priority)
+  }
+
+  /**
+   * @param {number} offset
+   * @return {ContentMove}
+   */
+  splice (offset) {
+    return this
+  }
+
+  /**
+   * @param {ContentMove} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    return false
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  integrate (transaction, item) {
+    /** @type {AbstractType<any>} */ (item.parent)._searchMarker = []
+    /**
+     * @type {{ start: Item | null, end: Item | null }}
+     */
+    let { start, end } = getMovedCoords(this, transaction)
+    let maxPriority = 0
+    // If this ContentMove was created locally, we set prio = -1. This indicates
+    // that we want to set prio to the current prio-maximum of the moved range.
+    const adaptPriority = this.priority < 0
+    while (start !== end && start != null) {
+      if (!start.deleted) {
+        const currMoved = start.moved
+        const nextPrio = currMoved ? /** @type {ContentMove} */ (currMoved.content).priority : -1
+        if (currMoved === null || adaptPriority || nextPrio < this.priority || currMoved.id.client < item.id.client || (currMoved.id.client === item.id.client && currMoved.id.clock < item.id.clock)) {
+          if (currMoved !== null) {
+            this.overrides.add(currMoved)
+          }
+          maxPriority = math.max(maxPriority, nextPrio)
+          // was already moved
+          if (start.moved && !transaction.prevMoved.has(start)) {
+            // we need to know which item previously moved an item
+            transaction.prevMoved.set(start, start.moved)
+          }
+          start.moved = item
+        } else {
+          /** @type {ContentMove} */ (currMoved.content).overrides.add(item)
+        }
+      }
+      start = start.right
+    }
+    if (adaptPriority) {
+      this.priority = maxPriority + 1
+    }
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  delete (transaction, item) {
+    /**
+     * @type {{ start: Item | null, end: Item | null }}
+     */
+    let { start, end } = getMovedCoords(this, transaction)
+    while (start !== end && start != null) {
+      if (start.moved === item) {
+        start.moved = null
+      }
+      start = start.right
+    }
+    /**
+     * @param {Item} reIntegrateItem
+     */
+    const reIntegrate = reIntegrateItem => {
+      const content = /** @type {ContentMove} */ (reIntegrateItem.content)
+      if (reIntegrateItem.deleted) {
+        // potentially we can integrate the items that reIntegrateItem overrides
+        content.overrides.forEach(reIntegrate)
+      } else {
+        content.integrate(transaction, reIntegrateItem)
+      }
+    }
+    this.overrides.forEach(reIntegrate)
+  }
+
+  /**
+   * @param {StructStore} store
+   */
+  gc (store) {}
+
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    const isCollapsed = this.isCollapsed()
+    encoding.writeUint8(encoder.restEncoder, isCollapsed ? 1 : 0)
+    encoder.writeBuf(encodeRelativePosition(this.start))
+    if (!isCollapsed) {
+      encoder.writeBuf(encodeRelativePosition(this.end))
+    }
+    encoding.writeVarUint(encoder.restEncoder, this.priority)
+  }
+
+  /**
+   * @return {number}
+   */
+  getRef () {
+    return 11
+  }
+
+  isCollapsed () {
+    return this.start.item === this.end.item && this.start.item !== null
+  }
+}
+
+/**
+ * @private
+ * @todo use binary encoding option for start & end relpos's
+ *
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {ContentMove}
+ */
+export const readContentMove = decoder => {
+  const isCollapsed = decoding.readUint8(decoder.restDecoder) === 1
+  const start = decodeRelativePosition(decoder.readBuf())
+  const end = isCollapsed ? start.clone() : decodeRelativePosition(decoder.readBuf())
+  if (isCollapsed) {
+    end.assoc = -1
+  }
+  return new ContentMove(start, end, decoding.readVarUint(decoder.restDecoder))
+}

src/structs/ContentString.js

@@ -0,0 +1,112 @@
+import {
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, Transaction, Item, StructStore // eslint-disable-line
+} from '../internals.js'
+
+/**
+ * @private
+ */
+export class ContentString {
+  /**
+   * @param {string} str
+   */
+  constructor (str) {
+    /**
+     * @type {string}
+     */
+    this.str = str
+  }
+
+  /**
+   * @return {number}
+   */
+  getLength () {
+    return this.str.length
+  }
+
+  /**
+   * @return {Array<any>}
+   */
+  getContent () {
+    return this.str.split('')
+  }
+
+  /**
+   * @return {boolean}
+   */
+  isCountable () {
+    return true
+  }
+
+  /**
+   * @return {ContentString}
+   */
+  copy () {
+    return new ContentString(this.str)
+  }
+
+  /**
+   * @param {number} offset
+   * @return {ContentString}
+   */
+  splice (offset) {
+    const right = new ContentString(this.str.slice(offset))
+    this.str = this.str.slice(0, offset)
+
+    // Prevent encoding invalid documents because of splitting of surrogate pairs: https://github.com/yjs/yjs/issues/248
+    const firstCharCode = this.str.charCodeAt(offset - 1)
+    if (firstCharCode >= 0xD800 && firstCharCode <= 0xDBFF) {
+      // Last character of the left split is the start of a surrogate utf16/ucs2 pair.
+      // We don't support splitting of surrogate pairs because this may lead to invalid documents.
+      // Replace the invalid character with a unicode replacement character (<28> / U+FFFD)
+      this.str = this.str.slice(0, offset - 1) + '<27>'
+      // replace right as well
+      right.str = '<27>' + right.str.slice(1)
+    }
+    return right
+  }
+
+  /**
+   * @param {ContentString} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    this.str += right.str
+    return true
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  integrate (transaction, item) {}
+  /**
+   * @param {Transaction} transaction
+   */
+  delete (transaction) {}
+  /**
+   * @param {StructStore} store
+   */
+  gc (store) {}
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    encoder.writeString(offset === 0 ? this.str : this.str.slice(offset))
+  }
+
+  /**
+   * @return {number}
+   */
+  getRef () {
+    return 4
+  }
+}
+
+/**
+ * @private
+ *
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {ContentString}
+ */
+export const readContentString = decoder => new ContentString(decoder.readString())

src/structs/ContentType.js

@@ -0,0 +1,172 @@
+
+import {
+  readYArray,
+  readYMap,
+  readYText,
+  readYXmlElement,
+  readYXmlFragment,
+  readYXmlHook,
+  readYXmlText,
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, StructStore, Transaction, Item, YEvent, AbstractType // eslint-disable-line
+} from '../internals.js'
+
+import * as error from 'lib0/error'
+
+/**
+ * @type {Array<function(UpdateDecoderV1 | UpdateDecoderV2):AbstractType<any>>}
+ * @private
+ */
+export const typeRefs = [
+  readYArray,
+  readYMap,
+  readYText,
+  readYXmlElement,
+  readYXmlFragment,
+  readYXmlHook,
+  readYXmlText
+]
+
+export const YArrayRefID = 0
+export const YMapRefID = 1
+export const YTextRefID = 2
+export const YXmlElementRefID = 3
+export const YXmlFragmentRefID = 4
+export const YXmlHookRefID = 5
+export const YXmlTextRefID = 6
+
+/**
+ * @private
+ */
+export class ContentType {
+  /**
+   * @param {AbstractType<YEvent>} type
+   */
+  constructor (type) {
+    /**
+     * @type {AbstractType<any>}
+     */
+    this.type = type
+  }
+
+  /**
+   * @return {number}
+   */
+  getLength () {
+    return 1
+  }
+
+  /**
+   * @return {Array<any>}
+   */
+  getContent () {
+    return [this.type]
+  }
+
+  /**
+   * @return {boolean}
+   */
+  isCountable () {
+    return true
+  }
+
+  /**
+   * @return {ContentType}
+   */
+  copy () {
+    return new ContentType(this.type._copy())
+  }
+
+  /**
+   * @param {number} offset
+   * @return {ContentType}
+   */
+  splice (offset) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {ContentType} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    return false
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  integrate (transaction, item) {
+    this.type._integrate(transaction.doc, item)
+  }
+
+  /**
+   * @param {Transaction} transaction
+   */
+  delete (transaction) {
+    let item = this.type._start
+    while (item !== null) {
+      if (!item.deleted) {
+        item.delete(transaction)
+      } else {
+        // Whis will be gc'd later and we want to merge it if possible
+        // We try to merge all deleted items after each transaction,
+        // but we have no knowledge about that this needs to be merged
+        // since it is not in transaction.ds. Hence we add it to transaction._mergeStructs
+        transaction._mergeStructs.push(item)
+      }
+      item = item.right
+    }
+    this.type._map.forEach(item => {
+      if (!item.deleted) {
+        item.delete(transaction)
+      } else {
+        // same as above
+        transaction._mergeStructs.push(item)
+      }
+    })
+    transaction.changed.delete(this.type)
+  }
+
+  /**
+   * @param {StructStore} store
+   */
+  gc (store) {
+    let item = this.type._start
+    while (item !== null) {
+      item.gc(store, true)
+      item = item.right
+    }
+    this.type._start = null
+    this.type._map.forEach(/** @param {Item | null} item */ (item) => {
+      while (item !== null) {
+        item.gc(store, true)
+        item = item.left
+      }
+    })
+    this.type._map = new Map()
+  }
+
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    this.type._write(encoder)
+  }
+
+  /**
+   * @return {number}
+   */
+  getRef () {
+    return 7
+  }
+}
+
+/**
+ * @private
+ *
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {ContentType}
+ */
+export const readContentType = decoder => new ContentType(typeRefs[decoder.readTypeRef()](decoder))

src/structs/GC.js

@@ -0,0 +1,61 @@
+
+import {
+  AbstractStruct,
+  addStruct,
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, StructStore, Transaction, ID // eslint-disable-line
+} from '../internals.js'
+
+export const structGCRefNumber = 0
+
+/**
+ * @private
+ */
+export class GC extends AbstractStruct {
+  get deleted () {
+    return true
+  }
+
+  delete () {}
+
+  /**
+   * @param {GC} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    if (this.constructor !== right.constructor) {
+      return false
+    }
+    this.length += right.length
+    return true
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {number} offset
+   */
+  integrate (transaction, offset) {
+    if (offset > 0) {
+      this.id.clock += offset
+      this.length -= offset
+    }
+    addStruct(transaction.doc.store, this)
+  }
+
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    encoder.writeInfo(structGCRefNumber)
+    encoder.writeLen(this.length - offset)
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {StructStore} store
+   * @return {null | number}
+   */
+  getMissing (transaction, store) {
+    return null
+  }
+}

src/structs/Item.js

@@ -0,0 +1,836 @@
+
+import {
+  GC,
+  getState,
+  AbstractStruct,
+  replaceStruct,
+  addStruct,
+  addToDeleteSet,
+  findRootTypeKey,
+  compareIDs,
+  getItem,
+  getItemCleanEnd,
+  getItemCleanStart,
+  readContentDeleted,
+  readContentBinary,
+  readContentJSON,
+  readContentAny,
+  readContentString,
+  readContentEmbed,
+  readContentDoc,
+  createID,
+  readContentFormat,
+  readContentType,
+  readContentMove,
+  addChangedTypeToTransaction,
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, ContentType, ContentDeleted, StructStore, ID, AbstractType, Transaction // eslint-disable-line
+} from '../internals.js'
+
+import * as error from 'lib0/error'
+import * as binary from 'lib0/binary'
+import { ContentMove } from './ContentMove.js'
+
+/**
+ * @todo This should return several items
+ *
+ * @param {StructStore} store
+ * @param {ID} id
+ * @return {{item:Item, diff:number}}
+ */
+export const followRedone = (store, id) => {
+  /**
+   * @type {ID|null}
+   */
+  let nextID = id
+  let diff = 0
+  let item
+  do {
+    if (diff > 0) {
+      nextID = createID(nextID.client, nextID.clock + diff)
+    }
+    item = getItem(store, nextID)
+    diff = nextID.clock - item.id.clock
+    nextID = item.redone
+  } while (nextID !== null && item instanceof Item)
+  return {
+    item, diff
+  }
+}
+
+/**
+ * Make sure that neither item nor any of its parents is ever deleted.
+ *
+ * This property does not persist when storing it into a database or when
+ * sending it to other peers
+ *
+ * @param {Item|null} item
+ * @param {boolean} keep
+ */
+export const keepItem = (item, keep) => {
+  while (item !== null && item.keep !== keep) {
+    item.keep = keep
+    item = /** @type {AbstractType<any>} */ (item.parent)._item
+  }
+}
+
+/**
+ * Split leftItem into two items
+ * @param {Transaction} transaction
+ * @param {Item} leftItem
+ * @param {number} diff
+ * @return {Item}
+ *
+ * @function
+ * @private
+ */
+export const splitItem = (transaction, leftItem, diff) => {
+  // create rightItem
+  const { client, clock } = leftItem.id
+  const rightItem = new Item(
+    createID(client, clock + diff),
+    leftItem,
+    createID(client, clock + diff - 1),
+    leftItem.right,
+    leftItem.rightOrigin,
+    leftItem.parent,
+    leftItem.parentSub,
+    leftItem.content.splice(diff)
+  )
+  if (leftItem.deleted) {
+    rightItem.markDeleted()
+  }
+  if (leftItem.keep) {
+    rightItem.keep = true
+  }
+  if (leftItem.redone !== null) {
+    rightItem.redone = createID(leftItem.redone.client, leftItem.redone.clock + diff)
+  }
+  // update left (do not set leftItem.rightOrigin as it will lead to problems when syncing)
+  leftItem.right = rightItem
+  // update right
+  if (rightItem.right !== null) {
+    rightItem.right.left = rightItem
+  }
+  // right is more specific.
+  transaction._mergeStructs.push(rightItem)
+  // update parent._map
+  if (rightItem.parentSub !== null && rightItem.right === null) {
+    /** @type {AbstractType<any>} */ (rightItem.parent)._map.set(rightItem.parentSub, rightItem)
+  }
+  leftItem.length = diff
+  if (leftItem.moved) {
+    const m = transaction.prevMoved.get(leftItem)
+    if (m) {
+      transaction.prevMoved.set(rightItem, m)
+    }
+  }
+  return rightItem
+}
+
+/**
+ * Redoes the effect of this operation.
+ *
+ * @param {Transaction} transaction The Yjs instance.
+ * @param {Item} item
+ * @param {Set<Item>} redoitems
+ * @param {Array<Item>} itemsToDelete
+ *
+ * @return {Item|null}
+ *
+ * @private
+ */
+export const redoItem = (transaction, item, redoitems, itemsToDelete) => {
+  const doc = transaction.doc
+  const store = doc.store
+  const ownClientID = doc.clientID
+  const redone = item.redone
+  if (redone !== null) {
+    return getItemCleanStart(transaction, redone)
+  }
+  let parentItem = /** @type {AbstractType<any>} */ (item.parent)._item
+  /**
+   * @type {Item|null}
+   */
+  let left
+  /**
+   * @type {Item|null}
+   */
+  let right
+  if (item.parentSub === null) {
+    // Is an array item. Insert at the old position
+    left = item.left
+    right = item
+  } else {
+    // Is a map item. Insert as current value
+    left = item
+    while (left.right !== null) {
+      left = left.right
+      if (left.id.client !== ownClientID) {
+        // It is not possible to redo this item because it conflicts with a
+        // change from another client
+        return null
+      }
+    }
+    if (left.right !== null) {
+      left = /** @type {Item} */ (/** @type {AbstractType<any>} */ (item.parent)._map.get(item.parentSub))
+    }
+    right = null
+  }
+  // make sure that parent is redone
+  if (parentItem !== null && parentItem.deleted === true && parentItem.redone === null) {
+    // try to undo parent if it will be undone anyway
+    if (!redoitems.has(parentItem) || redoItem(transaction, parentItem, redoitems, itemsToDelete) === null) {
+      return null
+    }
+  }
+  if (parentItem !== null && parentItem.redone !== null) {
+    while (parentItem.redone !== null) {
+      parentItem = getItemCleanStart(transaction, parentItem.redone)
+    }
+    // find next cloned_redo items
+    while (left !== null) {
+      /**
+       * @type {Item|null}
+       */
+      let leftTrace = left
+      // trace redone until parent matches
+      while (leftTrace !== null && /** @type {AbstractType<any>} */ (leftTrace.parent)._item !== parentItem) {
+        leftTrace = leftTrace.redone === null ? null : getItemCleanStart(transaction, leftTrace.redone)
+      }
+      if (leftTrace !== null && /** @type {AbstractType<any>} */ (leftTrace.parent)._item === parentItem) {
+        left = leftTrace
+        break
+      }
+      left = left.left
+    }
+    while (right !== null) {
+      /**
+       * @type {Item|null}
+       */
+      let rightTrace = right
+      // trace redone until parent matches
+      while (rightTrace !== null && /** @type {AbstractType<any>} */ (rightTrace.parent)._item !== parentItem) {
+        rightTrace = rightTrace.redone === null ? null : getItemCleanStart(transaction, rightTrace.redone)
+      }
+      if (rightTrace !== null && /** @type {AbstractType<any>} */ (rightTrace.parent)._item === parentItem) {
+        right = rightTrace
+        break
+      }
+      right = right.right
+    }
+    // Iterate right while right is in itemsToDelete
+    // If it is intended to delete right while item is redone, we can expect that item should replace right.
+    while (left !== null && left.right !== null && left.right !== right && itemsToDelete.findIndex(d => d === /** @type {Item} */ (left).right) >= 0) {
+      left = left.right
+    }
+  }
+  const nextClock = getState(store, ownClientID)
+  const nextId = createID(ownClientID, nextClock)
+  const redoneItem = new Item(
+    nextId,
+    left, left && left.lastId,
+    right, right && right.id,
+    parentItem === null ? item.parent : /** @type {ContentType} */ (parentItem.content).type,
+    item.parentSub,
+    item.content.copy()
+  )
+  item.redone = nextId
+  keepItem(redoneItem, true)
+  redoneItem.integrate(transaction, 0)
+  return redoneItem
+}
+
+/**
+ * Abstract class that represents any content.
+ */
+export class Item extends AbstractStruct {
+  /**
+   * @param {ID} id
+   * @param {Item | null} left
+   * @param {ID | null} origin
+   * @param {Item | null} right
+   * @param {ID | null} rightOrigin
+   * @param {AbstractType<any>|ID|null} parent Is a type if integrated, is null if it is possible to copy parent from left or right, is ID before integration to search for it.
+   * @param {string | null} parentSub
+   * @param {AbstractContent} content
+   */
+  constructor (id, left, origin, right, rightOrigin, parent, parentSub, content) {
+    super(id, content.getLength())
+    /**
+     * The item that was originally to the left of this item.
+     * @type {ID | null}
+     */
+    this.origin = origin
+    /**
+     * The item that is currently to the left of this item.
+     * @type {Item | null}
+     */
+    this.left = left
+    /**
+     * The item that is currently to the right of this item.
+     * @type {Item | null}
+     */
+    this.right = right
+    /**
+     * The item that was originally to the right of this item.
+     * @type {ID | null}
+     */
+    this.rightOrigin = rightOrigin
+    /**
+     * @type {AbstractType<any>|ID|null}
+     */
+    this.parent = parent
+    /**
+     * If the parent refers to this item with some kind of key (e.g. YMap, the
+     * key is specified here. The key is then used to refer to the list in which
+     * to insert this item. If `parentSub = null` type._start is the list in
+     * which to insert to. Otherwise it is `parent._map`.
+     * @type {String | null}
+     */
+    this.parentSub = parentSub
+    /**
+     * If this type's effect is reundone this type refers to the type-id that undid
+     * this operation.
+     *
+     * @type {ID | null}
+     */
+    this.redone = null
+    /**
+     * This property is reused by the moved prop. In this case this property refers to an Item.
+     *
+     * @type {Item | null}
+     */
+    this.moved = null
+    /**
+     * @type {AbstractContent}
+     */
+    this.content = content
+    /**
+     * bit1: keep
+     * bit2: countable
+     * bit3: deleted
+     * bit4: mark - mark node as fast-search-marker
+     * @type {number} byte
+     */
+    this.info = this.content.isCountable() ? binary.BIT2 : 0
+  }
+
+  /**
+   * This is used to mark the item as an indexed fast-search marker
+   *
+   * @type {boolean}
+   */
+  set marker (isMarked) {
+    if (((this.info & binary.BIT4) > 0) !== isMarked) {
+      this.info ^= binary.BIT4
+    }
+  }
+
+  get marker () {
+    return (this.info & binary.BIT4) > 0
+  }
+
+  /**
+   * If true, do not garbage collect this Item.
+   */
+  get keep () {
+    return (this.info & binary.BIT1) > 0
+  }
+
+  set keep (doKeep) {
+    if (this.keep !== doKeep) {
+      this.info ^= binary.BIT1
+    }
+  }
+
+  get countable () {
+    return (this.info & binary.BIT2) > 0
+  }
+
+  /**
+   * Whether this item was deleted or not.
+   * @type {Boolean}
+   */
+  get deleted () {
+    return (this.info & binary.BIT3) > 0
+  }
+
+  set deleted (doDelete) {
+    if (this.deleted !== doDelete) {
+      this.info ^= binary.BIT3
+    }
+  }
+
+  markDeleted () {
+    this.info |= binary.BIT3
+  }
+
+  /**
+   * Return the creator clientID of the missing op or define missing items and return null.
+   *
+   * @param {Transaction} transaction
+   * @param {StructStore} store
+   * @return {null | number}
+   */
+  getMissing (transaction, store) {
+    if (this.origin && this.origin.client !== this.id.client && this.origin.clock >= getState(store, this.origin.client)) {
+      return this.origin.client
+    }
+    if (this.rightOrigin && this.rightOrigin.client !== this.id.client && this.rightOrigin.clock >= getState(store, this.rightOrigin.client)) {
+      return this.rightOrigin.client
+    }
+    if (this.parent && this.parent.constructor === ID && this.id.client !== this.parent.client && this.parent.clock >= getState(store, this.parent.client)) {
+      return this.parent.client
+    }
+    if (this.content.constructor === ContentMove) {
+      const c = /** @type {ContentMove} */ (this.content)
+      const start = c.start.item
+      const end = c.isCollapsed() ? null : c.end.item
+      if (start && start.clock >= getState(store, start.client)) {
+        return start.client
+      }
+      if (end && end.clock >= getState(store, end.client)) {
+        return end.client
+      }
+    }
+
+    // We have all missing ids, now find the items
+    if (this.origin) {
+      this.left = getItemCleanEnd(transaction, this.origin)
+      this.origin = this.left.lastId
+    }
+    if (this.rightOrigin) {
+      this.right = getItemCleanStart(transaction, this.rightOrigin)
+      this.rightOrigin = this.right.id
+    }
+    if ((this.left && this.left.constructor === GC) || (this.right && this.right.constructor === GC)) {
+      this.parent = null
+    }
+    // only set parent if this shouldn't be garbage collected
+    if (!this.parent) {
+      if (this.left && this.left.constructor === Item) {
+        this.parent = this.left.parent
+        this.parentSub = this.left.parentSub
+      }
+      if (this.right && this.right.constructor === Item) {
+        this.parent = this.right.parent
+        this.parentSub = this.right.parentSub
+      }
+    } else if (this.parent.constructor === ID) {
+      const parentItem = getItem(store, this.parent)
+      if (parentItem.constructor === GC) {
+        this.parent = null
+      } else {
+        this.parent = /** @type {ContentType} */ (parentItem.content).type
+      }
+    }
+
+    return null
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {number} offset
+   */
+  integrate (transaction, offset) {
+    if (offset > 0) {
+      this.id.clock += offset
+      this.left = getItemCleanEnd(transaction, createID(this.id.client, this.id.clock - 1))
+      this.origin = this.left.lastId
+      this.content = this.content.splice(offset)
+      this.length -= offset
+    }
+
+    if (this.parent) {
+      if ((!this.left && (!this.right || this.right.left !== null)) || (this.left && this.left.right !== this.right)) {
+        /**
+         * @type {Item|null}
+         */
+        let left = this.left
+
+        /**
+         * @type {Item|null}
+         */
+        let o
+        // set o to the first conflicting item
+        if (left !== null) {
+          o = left.right
+        } else if (this.parentSub !== null) {
+          o = /** @type {AbstractType<any>} */ (this.parent)._map.get(this.parentSub) || null
+          while (o !== null && o.left !== null) {
+            o = o.left
+          }
+        } else {
+          o = /** @type {AbstractType<any>} */ (this.parent)._start
+        }
+        // TODO: use something like DeleteSet here (a tree implementation would be best)
+        // @todo use global set definitions
+        /**
+         * @type {Set<Item>}
+         */
+        const conflictingItems = new Set()
+        /**
+         * @type {Set<Item>}
+         */
+        const itemsBeforeOrigin = new Set()
+        // Let c in conflictingItems, b in itemsBeforeOrigin
+        // ***{origin}bbbb{this}{c,b}{c,b}{o}***
+        // Note that conflictingItems is a subset of itemsBeforeOrigin
+        while (o !== null && o !== this.right) {
+          itemsBeforeOrigin.add(o)
+          conflictingItems.add(o)
+          if (compareIDs(this.origin, o.origin)) {
+            // case 1
+            if (o.id.client < this.id.client) {
+              left = o
+              conflictingItems.clear()
+            } else if (compareIDs(this.rightOrigin, o.rightOrigin)) {
+              // this and o are conflicting and point to the same integration points. The id decides which item comes first.
+              // Since this is to the left of o, we can break here
+              break
+            } // else, o might be integrated before an item that this conflicts with. If so, we will find it in the next iterations
+          } else if (o.origin !== null && itemsBeforeOrigin.has(getItem(transaction.doc.store, o.origin))) { // use getItem instead of getItemCleanEnd because we don't want / need to split items.
+            // case 2
+            if (!conflictingItems.has(getItem(transaction.doc.store, o.origin))) {
+              left = o
+              conflictingItems.clear()
+            }
+          } else {
+            break
+          }
+          o = o.right
+        }
+        this.left = left
+      }
+      // reconnect left/right + update parent map/start if necessary
+      if (this.left !== null) {
+        const right = this.left.right
+        this.right = right
+        this.left.right = this
+      } else {
+        let r
+        if (this.parentSub !== null) {
+          r = /** @type {AbstractType<any>} */ (this.parent)._map.get(this.parentSub) || null
+          while (r !== null && r.left !== null) {
+            r = r.left
+          }
+        } else {
+          r = /** @type {AbstractType<any>} */ (this.parent)._start
+          ;/** @type {AbstractType<any>} */ (this.parent)._start = this
+        }
+        this.right = r
+      }
+      if (this.right !== null) {
+        this.right.left = this
+      } else if (this.parentSub !== null) {
+        // set as current parent value if right === null and this is parentSub
+        /** @type {AbstractType<any>} */ (this.parent)._map.set(this.parentSub, this)
+        if (this.left !== null) {
+          // this is the current attribute value of parent. delete right
+          this.left.delete(transaction)
+        }
+      }
+      // adjust length of parent
+      if (this.parentSub === null && this.countable && !this.deleted) {
+        /** @type {AbstractType<any>} */ (this.parent)._length += this.length
+      }
+      addStruct(transaction.doc.store, this)
+      this.content.integrate(transaction, this)
+      // add parent to transaction.changed
+      addChangedTypeToTransaction(transaction, /** @type {AbstractType<any>} */ (this.parent), this.parentSub)
+      if ((/** @type {AbstractType<any>} */ (this.parent)._item !== null && /** @type {AbstractType<any>} */ (this.parent)._item.deleted) || (this.parentSub !== null && this.right !== null)) {
+        // delete if parent is deleted or if this is not the current attribute value of parent
+        this.delete(transaction)
+      }
+    } else {
+      // parent is not defined. Integrate GC struct instead
+      new GC(this.id, this.length).integrate(transaction, 0)
+    }
+  }
+
+  /**
+   * Returns the next non-deleted item
+   */
+  get next () {
+    let n = this.right
+    while (n !== null && n.deleted) {
+      n = n.right
+    }
+    return n
+  }
+
+  /**
+   * Returns the previous non-deleted item
+   */
+  get prev () {
+    let n = this.left
+    while (n !== null && n.deleted) {
+      n = n.left
+    }
+    return n
+  }
+
+  /**
+   * Computes the last content address of this Item.
+   */
+  get lastId () {
+    // allocating ids is pretty costly because of the amount of ids created, so we try to reuse whenever possible
+    return this.length === 1 ? this.id : createID(this.id.client, this.id.clock + this.length - 1)
+  }
+
+  /**
+   * Try to merge two items
+   *
+   * @param {Item} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    if (
+      this.constructor === right.constructor &&
+      compareIDs(right.origin, this.lastId) &&
+      this.right === right &&
+      compareIDs(this.rightOrigin, right.rightOrigin) &&
+      this.id.client === right.id.client &&
+      this.id.clock + this.length === right.id.clock &&
+      this.deleted === right.deleted &&
+      this.redone === null &&
+      right.redone === null &&
+      this.moved === right.moved &&
+      this.content.constructor === right.content.constructor &&
+      this.content.mergeWith(right.content)
+    ) {
+      if (right.marker) {
+        // Right will be "forgotten", so we delete all
+        // search markers that reference right.
+        const searchMarker = /** @type {AbstractType<any>} */ (this.parent)._searchMarker
+        if (searchMarker) {
+          for (let i = searchMarker.length - 1; i >= 0; i--) {
+            if (searchMarker[i].nextItem === right) {
+              // @todo do something more efficient than splicing..
+              searchMarker.splice(i, 1)
+            }
+          }
+        }
+      }
+      if (right.keep) {
+        this.keep = true
+      }
+      this.right = right.right
+      if (this.right !== null) {
+        this.right.left = this
+      }
+      this.length += right.length
+      return true
+    }
+    return false
+  }
+
+  /**
+   * Mark this Item as deleted.
+   *
+   * @param {Transaction} transaction
+   */
+  delete (transaction) {
+    if (!this.deleted) {
+      const parent = /** @type {AbstractType<any>} */ (this.parent)
+      // adjust the length of parent
+      if (this.countable && this.parentSub === null) {
+        parent._length -= this.length
+      }
+      this.markDeleted()
+      addToDeleteSet(transaction.deleteSet, this.id.client, this.id.clock, this.length)
+      addChangedTypeToTransaction(transaction, parent, this.parentSub)
+      this.content.delete(transaction, this)
+    }
+  }
+
+  /**
+   * @param {StructStore} store
+   * @param {boolean} parentGCd
+   */
+  gc (store, parentGCd) {
+    if (!this.deleted) {
+      throw error.unexpectedCase()
+    }
+    this.moved = null
+    this.content.gc(store)
+    if (parentGCd) {
+      replaceStruct(store, this, new GC(this.id, this.length))
+    } else {
+      this.content = new ContentDeleted(this.length)
+    }
+  }
+
+  /**
+   * Transform the properties of this type to binary and write it to an
+   * BinaryEncoder.
+   *
+   * This is called when this Item is sent to a remote peer.
+   *
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder The encoder to write data to.
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    const origin = offset > 0 ? createID(this.id.client, this.id.clock + offset - 1) : this.origin
+    const rightOrigin = this.rightOrigin
+    const parentSub = this.parentSub
+    const info = (this.content.getRef() & binary.BITS5) |
+      (origin === null ? 0 : binary.BIT8) | // origin is defined
+      (rightOrigin === null ? 0 : binary.BIT7) | // right origin is defined
+      (parentSub === null ? 0 : binary.BIT6) // parentSub is non-null
+    encoder.writeInfo(info)
+    if (origin !== null) {
+      encoder.writeLeftID(origin)
+    }
+    if (rightOrigin !== null) {
+      encoder.writeRightID(rightOrigin)
+    }
+    if (origin === null && rightOrigin === null) {
+      const parent = /** @type {AbstractType<any>} */ (this.parent)
+      if (parent._item !== undefined) {
+        const parentItem = parent._item
+        if (parentItem === null) {
+          // parent type on y._map
+          // find the correct key
+          const ykey = findRootTypeKey(parent)
+          encoder.writeParentInfo(true) // write parentYKey
+          encoder.writeString(ykey)
+        } else {
+          encoder.writeParentInfo(false) // write parent id
+          encoder.writeLeftID(parentItem.id)
+        }
+      } else if (parent.constructor === String) { // this edge case was added by differential updates
+        encoder.writeParentInfo(true) // write parentYKey
+        encoder.writeString(parent)
+      } else if (parent.constructor === ID) {
+        encoder.writeParentInfo(false) // write parent id
+        encoder.writeLeftID(parent)
+      } else {
+        error.unexpectedCase()
+      }
+      if (parentSub !== null) {
+        encoder.writeString(parentSub)
+      }
+    }
+    this.content.write(encoder, offset)
+  }
+}
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @param {number} info
+ */
+export const readItemContent = (decoder, info) => contentRefs[info & binary.BITS5](decoder)
+
+/**
+ * A lookup map for reading Item content.
+ *
+ * @type {Array<function(UpdateDecoderV1 | UpdateDecoderV2):AbstractContent>}
+ */
+export const contentRefs = [
+  () => { error.unexpectedCase() }, // GC is not ItemContent
+  readContentDeleted, // 1
+  readContentJSON, // 2
+  readContentBinary, // 3
+  readContentString, // 4
+  readContentEmbed, // 5
+  readContentFormat, // 6
+  readContentType, // 7
+  readContentAny, // 8
+  readContentDoc, // 9
+  () => { error.unexpectedCase() }, // 10 - Skip is not ItemContent
+  readContentMove // 11
+]
+
+/**
+ * Do not implement this class!
+ */
+export class AbstractContent {
+  /**
+   * @return {number}
+   */
+  getLength () {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @return {Array<any>}
+   */
+  getContent () {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * Should return false if this Item is some kind of meta information
+   * (e.g. format information).
+   *
+   * * Whether this Item should be addressable via `yarray.get(i)`
+   * * Whether this Item should be counted when computing yarray.length
+   *
+   * @return {boolean}
+   */
+  isCountable () {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @return {AbstractContent}
+   */
+  copy () {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {number} offset
+   * @return {AbstractContent}
+   */
+  splice (offset) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {AbstractContent} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  integrate (transaction, item) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  delete (transaction, item) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {StructStore} store
+   */
+  gc (store) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @return {number}
+   */
+  getRef () {
+    throw error.methodUnimplemented()
+  }
+}

src/structs/Skip.js

@@ -0,0 +1,60 @@
+
+import {
+  AbstractStruct,
+  UpdateEncoderV1, UpdateEncoderV2, StructStore, Transaction, ID // eslint-disable-line
+} from '../internals.js'
+import * as error from 'lib0/error'
+import * as encoding from 'lib0/encoding'
+
+export const structSkipRefNumber = 10
+
+/**
+ * @private
+ */
+export class Skip extends AbstractStruct {
+  get deleted () {
+    return true
+  }
+
+  delete () {}
+
+  /**
+   * @param {Skip} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    if (this.constructor !== right.constructor) {
+      return false
+    }
+    this.length += right.length
+    return true
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {number} offset
+   */
+  integrate (transaction, offset) {
+    // skip structs cannot be integrated
+    error.unexpectedCase()
+  }
+
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    encoder.writeInfo(structSkipRefNumber)
+    // write as VarUint because Skips can't make use of predictable length-encoding
+    encoding.writeVarUint(encoder.restEncoder, this.length - offset)
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {StructStore} store
+   * @return {null | number}
+   */
+  getMissing (transaction, store) {
+    return null
+  }
+}

src/types/AbstractType.js

@@ -0,0 +1,707 @@
+
+import {
+  removeEventHandlerListener,
+  callEventHandlerListeners,
+  addEventHandlerListener,
+  createEventHandler,
+  getState,
+  isVisible,
+  ContentType,
+  createID,
+  ContentAny,
+  ContentBinary,
+  ListIterator,
+  ContentDoc, YText, YArray, UpdateEncoderV1, UpdateEncoderV2, Doc, Snapshot, Transaction, EventHandler, YEvent, Item, // eslint-disable-line
+} from '../internals.js'
+
+import * as map from 'lib0/map'
+import * as iterator from 'lib0/iterator'
+import * as error from 'lib0/error'
+import * as math from 'lib0/math'
+
+const maxSearchMarker = 80
+
+/**
+ * Search marker help us to find positions in the associative array faster.
+ *
+ * They speed up the process of finding a position without much bookkeeping.
+ *
+ * A maximum of `maxSearchMarker` objects are created.
+ *
+ * @template T
+ * @param {Transaction} tr
+ * @param {AbstractType<any>} yarray
+ * @param {number} index
+ * @param {function(ListIterator):T} f
+ */
+export const useSearchMarker = (tr, yarray, index, f) => {
+  const searchMarker = yarray._searchMarker
+  if (searchMarker === null || yarray._start === null || index < 5) {
+    return f(new ListIterator(yarray).forward(tr, index))
+  }
+  if (searchMarker.length === 0) {
+    const sm = new ListIterator(yarray).forward(tr, index)
+    searchMarker.push(sm)
+    if (sm.nextItem) sm.nextItem.marker = true
+  }
+  const sm = searchMarker.reduce(
+    (a, b, arrayIndex) => math.abs(index - a.index) < math.abs(index - b.index) ? a : b
+  )
+  const newIsCheaper = math.abs(sm.index - index) > index
+  const createFreshMarker = searchMarker.length < maxSearchMarker && (math.abs(sm.index - index) > 5 || newIsCheaper)
+  const fsm = createFreshMarker ? (newIsCheaper ? new ListIterator(yarray) : sm.clone()) : sm
+  const prevItem = /** @type {Item} */ (sm.nextItem)
+  if (createFreshMarker) {
+    searchMarker.push(fsm)
+  }
+  const diff = fsm.index - index
+  if (diff > 0) {
+    fsm.backward(tr, diff)
+  } else {
+    fsm.forward(tr, -diff)
+  }
+  // @todo remove this tests
+  /*
+  const otherTesting = new ListIterator(yarray)
+  otherTesting.forward(tr, index)
+  if (otherTesting.nextItem !== fsm.nextItem || otherTesting.index !== fsm.index || otherTesting.reachedEnd !== fsm.reachedEnd) {
+    throw new Error('udtirane')
+  }
+  */
+  const result = f(fsm)
+  if (fsm.reachedEnd) {
+    fsm.reachedEnd = false
+    const nextItem = /** @type {Item} */ (fsm.nextItem)
+    if (nextItem.countable && !nextItem.deleted) {
+      fsm.index -= nextItem.length
+    }
+    fsm.rel = 0
+  }
+  if (!createFreshMarker) {
+    // reused old marker and we moved to a different position
+    prevItem.marker = false
+  }
+  const fsmItem = fsm.nextItem
+  if (fsmItem) {
+    if (fsmItem.marker) {
+      // already marked, forget current iterator
+      searchMarker.splice(searchMarker.findIndex(m => m === fsm), 1)
+    } else {
+      fsmItem.marker = true
+    }
+  }
+  return result
+}
+
+/**
+ * Update markers when a change happened.
+ *
+ * This should be called before doing a deletion!
+ *
+ * @param {Array<ListIterator>} searchMarker
+ * @param {number} index
+ * @param {number} len If insertion, len is positive. If deletion, len is negative.
+ * @param {ListIterator|null} origSearchMarker Do not update this searchmarker because it is the one we used to manipulate. @todo !=null for improved perf in ytext
+ */
+export const updateMarkerChanges = (searchMarker, index, len, origSearchMarker) => {
+  for (let i = searchMarker.length - 1; i >= 0; i--) {
+    const marker = searchMarker[i]
+    if (marker !== origSearchMarker) {
+      if (len > 0 && index === marker.index) {
+        // inserting at a marked position deletes the marked position because we can't do a simple transformation
+        // (we don't know whether to insert directly before or directly after the position)
+        searchMarker.splice(i, 1)
+        if (marker.nextItem) marker.nextItem.marker = false
+        continue
+      }
+      if (index < marker.index) { // a simple index <= m.index check would actually suffice
+        marker.index = math.max(index, marker.index + len)
+      }
+    }
+  }
+}
+
+/**
+ * Accumulate all (list) children of a type and return them as an Array.
+ *
+ * @param {AbstractType<any>} t
+ * @return {Array<Item>}
+ */
+export const getTypeChildren = t => {
+  let s = t._start
+  const arr = []
+  while (s) {
+    arr.push(s)
+    s = s.right
+  }
+  return arr
+}
+
+/**
+ * Call event listeners with an event. This will also add an event to all
+ * parents (for `.observeDeep` handlers).
+ *
+ * @template EventType
+ * @param {AbstractType<EventType>} type
+ * @param {Transaction} transaction
+ * @param {EventType} event
+ */
+export const callTypeObservers = (type, transaction, event) => {
+  const changedType = type
+  const changedParentTypes = transaction.changedParentTypes
+  while (true) {
+    // @ts-ignore
+    map.setIfUndefined(changedParentTypes, type, () => []).push(event)
+    if (type._item === null) {
+      break
+    }
+    type = /** @type {AbstractType<any>} */ (type._item.parent)
+  }
+  callEventHandlerListeners(changedType._eH, event, transaction)
+}
+
+/**
+ * @template EventType
+ * Abstract Yjs Type class
+ */
+export class AbstractType {
+  constructor () {
+    /**
+     * @type {Item|null}
+     */
+    this._item = null
+    /**
+     * @type {Map<string,Item>}
+     */
+    this._map = new Map()
+    /**
+     * @type {Item|null}
+     */
+    this._start = null
+    /**
+     * @type {Doc|null}
+     */
+    this.doc = null
+    this._length = 0
+    /**
+     * Event handlers
+     * @type {EventHandler<EventType,Transaction>}
+     */
+    this._eH = createEventHandler()
+    /**
+     * Deep event handlers
+     * @type {EventHandler<Array<YEvent>,Transaction>}
+     */
+    this._dEH = createEventHandler()
+    /**
+     * @type {null | Array<ListIterator>}
+     */
+    this._searchMarker = null
+    /**
+     * You can store custom stuff here.
+     * This might be useful to associate your application state to this shared type.
+     *
+     * @type {Map<any, any>}
+     */
+    this.meta = new Map()
+  }
+
+  /**
+   * @return {AbstractType<any>|null}
+   */
+  get parent () {
+    return this._item ? /** @type {AbstractType<any>} */ (this._item.parent) : null
+  }
+
+  /**
+   * Integrate this type into the Yjs instance.
+   *
+   * * Save this struct in the os
+   * * This type is sent to other client
+   * * Observer functions are fired
+   *
+   * @param {Doc} y The Yjs instance
+   * @param {Item|null} item
+   */
+  _integrate (y, item) {
+    this.doc = y
+    this._item = item
+  }
+
+  /**
+   * @return {AbstractType<EventType>}
+   */
+  _copy () {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @return {AbstractType<EventType>}
+   */
+  clone () {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   */
+  _write (encoder) { }
+
+  /**
+   * The first non-deleted item
+   */
+  get _first () {
+    let n = this._start
+    while (n !== null && n.deleted) {
+      n = n.right
+    }
+    return n
+  }
+
+  /**
+   * Creates YEvent and calls all type observers.
+   * Must be implemented by each type.
+   *
+   * @param {Transaction} transaction
+   * @param {Set<null|string>} parentSubs Keys changed on this type. `null` if list was modified.
+   */
+  _callObserver (transaction, parentSubs) {
+    if (!transaction.local && this._searchMarker) {
+      this._searchMarker.length = 0
+    }
+  }
+
+  /**
+   * Observe all events that are created on this type.
+   *
+   * @param {function(EventType, Transaction):void} f Observer function
+   */
+  observe (f) {
+    addEventHandlerListener(this._eH, f)
+  }
+
+  /**
+   * Observe all events that are created by this type and its children.
+   *
+   * @param {function(Array<YEvent>,Transaction):void} f Observer function
+   */
+  observeDeep (f) {
+    addEventHandlerListener(this._dEH, f)
+  }
+
+  /**
+   * Unregister an observer function.
+   *
+   * @param {function(EventType,Transaction):void} f Observer function
+   */
+  unobserve (f) {
+    removeEventHandlerListener(this._eH, f)
+  }
+
+  /**
+   * Unregister an observer function.
+   *
+   * @param {function(Array<YEvent>,Transaction):void} f Observer function
+   */
+  unobserveDeep (f) {
+    removeEventHandlerListener(this._dEH, f)
+  }
+
+  /**
+   * @abstract
+   * @return {any}
+   */
+  toJSON () {}
+}
+
+/**
+ * @param {AbstractType<any>} type
+ * @param {number} start
+ * @param {number} end
+ * @return {Array<any>}
+ *
+ * @private
+ * @function
+ */
+export const typeListSlice = (type, start, end) => {
+  if (start < 0) {
+    start = type._length + start
+  }
+  if (end < 0) {
+    end = type._length + end
+  }
+  let len = end - start
+  const cs = []
+  let n = type._start
+  while (n !== null && len > 0) {
+    if (n.countable && !n.deleted) {
+      const c = n.content.getContent()
+      if (c.length <= start) {
+        start -= c.length
+      } else {
+        for (let i = start; i < c.length && len > 0; i++) {
+          cs.push(c[i])
+          len--
+        }
+        start = 0
+      }
+    }
+    n = n.right
+  }
+  return cs
+}
+
+/**
+ * @param {AbstractType<any>} type
+ * @return {Array<any>}
+ *
+ * @private
+ * @function
+ */
+export const typeListToArray = type => {
+  const cs = []
+  let n = type._start
+  while (n !== null) {
+    if (n.countable && !n.deleted) {
+      const c = n.content.getContent()
+      for (let i = 0; i < c.length; i++) {
+        cs.push(c[i])
+      }
+    }
+    n = n.right
+  }
+  return cs
+}
+
+/**
+ * @param {AbstractType<any>} type
+ * @param {Snapshot} snapshot
+ * @return {Array<any>}
+ *
+ * @private
+ * @function
+ */
+export const typeListToArraySnapshot = (type, snapshot) => {
+  const cs = []
+  let n = type._start
+  while (n !== null) {
+    if (n.countable && isVisible(n, snapshot)) {
+      const c = n.content.getContent()
+      for (let i = 0; i < c.length; i++) {
+        cs.push(c[i])
+      }
+    }
+    n = n.right
+  }
+  return cs
+}
+
+/**
+ * Executes a provided function on once on overy element of this YArray.
+ *
+ * @param {AbstractType<any>} type
+ * @param {function(any,number,any):void} f A function to execute on every element of this YArray.
+ *
+ * @private
+ * @function
+ */
+export const typeListForEach = (type, f) => {
+  let index = 0
+  let n = type._start
+  while (n !== null) {
+    if (n.countable && !n.deleted) {
+      const c = n.content.getContent()
+      for (let i = 0; i < c.length; i++) {
+        f(c[i], index++, type)
+      }
+    }
+    n = n.right
+  }
+}
+
+/**
+ * @template C,R
+ * @param {AbstractType<any>} type
+ * @param {function(C,number,AbstractType<any>):R} f
+ * @return {Array<R>}
+ *
+ * @private
+ * @function
+ */
+export const typeListMap = (type, f) => {
+  /**
+   * @type {Array<any>}
+   */
+  const result = []
+  typeListForEach(type, (c, i) => {
+    result.push(f(c, i, type))
+  })
+  return result
+}
+
+/**
+ * @param {AbstractType<any>} type
+ * @return {IterableIterator<any>}
+ *
+ * @private
+ * @function
+ */
+export const typeListCreateIterator = type => {
+  let n = type._start
+  /**
+   * @type {Array<any>|null}
+   */
+  let currentContent = null
+  let currentContentIndex = 0
+  return {
+    [Symbol.iterator] () {
+      return this
+    },
+    next: () => {
+      // find some content
+      if (currentContent === null) {
+        while (n !== null && n.deleted) {
+          n = n.right
+        }
+        // check if we reached the end, no need to check currentContent, because it does not exist
+        if (n === null) {
+          return {
+            done: true,
+            value: undefined
+          }
+        }
+        // we found n, so we can set currentContent
+        currentContent = n.content.getContent()
+        currentContentIndex = 0
+        n = n.right // we used the content of n, now iterate to next
+      }
+      const value = currentContent[currentContentIndex++]
+      // check if we need to empty currentContent
+      if (currentContent.length <= currentContentIndex) {
+        currentContent = null
+      }
+      return {
+        done: false,
+        value
+      }
+    }
+  }
+}
+
+/**
+ * Executes a provided function on once on overy element of this YArray.
+ * Operates on a snapshotted state of the document.
+ *
+ * @param {AbstractType<any>} type
+ * @param {function(any,number,AbstractType<any>):void} f A function to execute on every element of this YArray.
+ * @param {Snapshot} snapshot
+ *
+ * @private
+ * @function
+ */
+export const typeListForEachSnapshot = (type, f, snapshot) => {
+  let index = 0
+  let n = type._start
+  while (n !== null) {
+    if (n.countable && isVisible(n, snapshot)) {
+      const c = n.content.getContent()
+      for (let i = 0; i < c.length; i++) {
+        f(c[i], index++, type)
+      }
+    }
+    n = n.right
+  }
+}
+
+/**
+ * @param {Transaction} transaction
+ * @param {AbstractType<any>} parent
+ * @param {Item?} referenceItem
+ * @param {Array<Object<string,any>|Array<any>|boolean|number|null|string|Uint8Array>} content
+ *
+ * @private
+ * @function
+ */
+export const typeListInsertGenericsAfter = (transaction, parent, referenceItem, content) => {
+  let left = referenceItem
+  const doc = transaction.doc
+  const ownClientId = doc.clientID
+  const store = doc.store
+  const right = referenceItem === null ? parent._start : referenceItem.right
+  /**
+   * @type {Array<Object|Array<any>|number|null>}
+   */
+  let jsonContent = []
+  const packJsonContent = () => {
+    if (jsonContent.length > 0) {
+      left = new Item(createID(ownClientId, getState(store, ownClientId)), left, left && left.lastId, right, right && right.id, parent, null, new ContentAny(jsonContent))
+      left.integrate(transaction, 0)
+      jsonContent = []
+    }
+  }
+  content.forEach(c => {
+    if (c === null) {
+      jsonContent.push(c)
+    } else {
+      switch (c.constructor) {
+        case Number:
+        case Object:
+        case Boolean:
+        case Array:
+        case String:
+          jsonContent.push(c)
+          break
+        default:
+          packJsonContent()
+          switch (c.constructor) {
+            case Uint8Array:
+            case ArrayBuffer:
+              left = new Item(createID(ownClientId, getState(store, ownClientId)), left, left && left.lastId, right, right && right.id, parent, null, new ContentBinary(new Uint8Array(/** @type {Uint8Array} */ (c))))
+              left.integrate(transaction, 0)
+              break
+            case Doc:
+              left = new Item(createID(ownClientId, getState(store, ownClientId)), left, left && left.lastId, right, right && right.id, parent, null, new ContentDoc(/** @type {Doc} */ (c)))
+              left.integrate(transaction, 0)
+              break
+            default:
+              if (c instanceof AbstractType) {
+                left = new Item(createID(ownClientId, getState(store, ownClientId)), left, left && left.lastId, right, right && right.id, parent, null, new ContentType(c))
+                left.integrate(transaction, 0)
+              } else {
+                throw new Error('Unexpected content type in insert operation')
+              }
+          }
+      }
+    }
+  })
+  packJsonContent()
+}
+
+/**
+ * @param {Transaction} transaction
+ * @param {AbstractType<any>} parent
+ * @param {string} key
+ *
+ * @private
+ * @function
+ */
+export const typeMapDelete = (transaction, parent, key) => {
+  const c = parent._map.get(key)
+  if (c !== undefined) {
+    c.delete(transaction)
+  }
+}
+
+/**
+ * @param {Transaction} transaction
+ * @param {AbstractType<any>} parent
+ * @param {string} key
+ * @param {Object|number|null|Array<any>|string|Uint8Array|AbstractType<any>} value
+ *
+ * @private
+ * @function
+ */
+export const typeMapSet = (transaction, parent, key, value) => {
+  const left = parent._map.get(key) || null
+  const doc = transaction.doc
+  const ownClientId = doc.clientID
+  let content
+  if (value == null) {
+    content = new ContentAny([value])
+  } else {
+    switch (value.constructor) {
+      case Number:
+      case Object:
+      case Boolean:
+      case Array:
+      case String:
+        content = new ContentAny([value])
+        break
+      case Uint8Array:
+        content = new ContentBinary(/** @type {Uint8Array} */ (value))
+        break
+      case Doc:
+        content = new ContentDoc(/** @type {Doc} */ (value))
+        break
+      default:
+        if (value instanceof AbstractType) {
+          content = new ContentType(value)
+        } else {
+          throw new Error('Unexpected content type')
+        }
+    }
+  }
+  new Item(createID(ownClientId, getState(doc.store, ownClientId)), left, left && left.lastId, null, null, parent, key, content).integrate(transaction, 0)
+}
+
+/**
+ * @param {AbstractType<any>} parent
+ * @param {string} key
+ * @return {Object<string,any>|number|null|Array<any>|string|Uint8Array|AbstractType<any>|undefined}
+ *
+ * @private
+ * @function
+ */
+export const typeMapGet = (parent, key) => {
+  const val = parent._map.get(key)
+  return val !== undefined && !val.deleted ? val.content.getContent()[val.length - 1] : undefined
+}
+
+/**
+ * @param {AbstractType<any>} parent
+ * @return {Object<string,Object<string,any>|number|null|Array<any>|string|Uint8Array|AbstractType<any>|undefined>}
+ *
+ * @private
+ * @function
+ */
+export const typeMapGetAll = (parent) => {
+  /**
+   * @type {Object<string,any>}
+   */
+  const res = {}
+  parent._map.forEach((value, key) => {
+    if (!value.deleted) {
+      res[key] = value.content.getContent()[value.length - 1]
+    }
+  })
+  return res
+}
+
+/**
+ * @param {AbstractType<any>} parent
+ * @param {string} key
+ * @return {boolean}
+ *
+ * @private
+ * @function
+ */
+export const typeMapHas = (parent, key) => {
+  const val = parent._map.get(key)
+  return val !== undefined && !val.deleted
+}
+
+/**
+ * @param {AbstractType<any>} parent
+ * @param {string} key
+ * @param {Snapshot} snapshot
+ * @return {Object<string,any>|number|null|Array<any>|string|Uint8Array|AbstractType<any>|undefined}
+ *
+ * @private
+ * @function
+ */
+export const typeMapGetSnapshot = (parent, key, snapshot) => {
+  let v = parent._map.get(key) || null
+  while (v !== null && (!snapshot.sv.has(v.id.client) || v.id.clock >= (snapshot.sv.get(v.id.client) || 0))) {
+    v = v.left
+  }
+  return v !== null && isVisible(v, snapshot) ? v.content.getContent()[v.length - 1] : undefined
+}
+
+/**
+ * @param {Map<string,Item>} map
+ * @return {IterableIterator<Array<any>>}
+ *
+ * @private
+ * @function
+ */
+export const createMapIterator = map => iterator.iteratorFilter(map.entries(), /** @param {any} entry */ entry => !entry[1].deleted)

src/types/YArray.js

@@ -0,0 +1,326 @@
+/**
+ * @module YArray
+ */
+
+import {
+  YEvent,
+  AbstractType,
+  YArrayRefID,
+  callTypeObservers,
+  transact,
+  ListIterator,
+  useSearchMarker,
+  createRelativePositionFromTypeIndex,
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, Doc, Transaction, Item // eslint-disable-line
+} from '../internals.js'
+
+/**
+ * Event that describes the changes on a YArray
+ * @template T
+ */
+export class YArrayEvent extends YEvent {
+  /**
+   * @param {YArray<T>} yarray The changed type
+   * @param {Transaction} transaction The transaction object
+   */
+  constructor (yarray, transaction) {
+    super(yarray, transaction)
+    this._transaction = transaction
+  }
+}
+
+/**
+ * A shared Array implementation.
+ * @template T
+ * @extends AbstractType<YArrayEvent<T>>
+ * @implements {Iterable<T>}
+ */
+export class YArray extends AbstractType {
+  constructor () {
+    super()
+    /**
+     * @type {Array<any>?}
+     * @private
+     */
+    this._prelimContent = []
+    /**
+     * @type {Array<ListIterator>}
+     */
+    this._searchMarker = []
+  }
+
+  /**
+   * Construct a new YArray containing the specified items.
+   * @template T
+   * @param {Array<T>} items
+   * @return {YArray<T>}
+   */
+  static from (items) {
+    const a = new YArray()
+    a.push(items)
+    return a
+  }
+
+  /**
+   * Integrate this type into the Yjs instance.
+   *
+   * * Save this struct in the os
+   * * This type is sent to other client
+   * * Observer functions are fired
+   *
+   * @param {Doc} y The Yjs instance
+   * @param {Item} item
+   */
+  _integrate (y, item) {
+    super._integrate(y, item)
+    this.insert(0, /** @type {Array<any>} */ (this._prelimContent))
+    this._prelimContent = null
+  }
+
+  _copy () {
+    return new YArray()
+  }
+
+  /**
+   * @return {YArray<T>}
+   */
+  clone () {
+    const arr = new YArray()
+    arr.insert(0, this.toArray().map(el =>
+      el instanceof AbstractType ? el.clone() : el
+    ))
+    return arr
+  }
+
+  get length () {
+    return this._prelimContent === null ? this._length : this._prelimContent.length
+  }
+
+  /**
+   * Creates YArrayEvent and calls observers.
+   *
+   * @param {Transaction} transaction
+   * @param {Set<null|string>} parentSubs Keys changed on this type. `null` if list was modified.
+   */
+  _callObserver (transaction, parentSubs) {
+    super._callObserver(transaction, parentSubs)
+    callTypeObservers(this, transaction, new YArrayEvent(this, transaction))
+  }
+
+  /**
+   * Inserts new content at an index.
+   *
+   * Important: This function expects an array of content. Not just a content
+   * object. The reason for this "weirdness" is that inserting several elements
+   * is very efficient when it is done as a single operation.
+   *
+   * @example
+   *  // Insert character 'a' at position 0
+   *  yarray.insert(0, ['a'])
+   *  // Insert numbers 1, 2 at position 1
+   *  yarray.insert(1, [1, 2])
+   *
+   * @param {number} index The index to insert content at.
+   * @param {Array<T>} content The array of content
+   */
+  insert (index, content) {
+    if (content.length > 0) {
+      if (this.doc !== null) {
+        transact(this.doc, transaction => {
+          useSearchMarker(transaction, this, index, walker =>
+            walker.insertArrayValue(transaction, content)
+          )
+        })
+      } else {
+        /** @type {Array<any>} */ (this._prelimContent).splice(index, 0, ...content)
+      }
+    }
+  }
+
+  /**
+   * Move a single item from $index to $target.
+   *
+   * @todo make sure that collapsed moves are removed (i.e. when moving the same item twice)
+   *
+   * @param {number} index
+   * @param {number} target
+   */
+  move (index, target) {
+    if (index === target || index + 1 === target || index >= this.length) {
+      // It doesn't make sense to move a range into the same range (it's basically a no-op).
+      return
+    }
+    if (this.doc !== null) {
+      transact(this.doc, transaction => {
+        const left = createRelativePositionFromTypeIndex(this, index, 1)
+        const right = left.clone()
+        right.assoc = -1
+        useSearchMarker(transaction, this, target, walker => {
+          walker.insertMove(transaction, left, right)
+        })
+      })
+    } else {
+      const content = /** @type {Array<any>} */ (this._prelimContent).splice(index, 1)
+      ;/** @type {Array<any>} */ (this._prelimContent).splice(target, 0, ...content)
+    }
+  }
+
+  /**
+   * @param {number} start Inclusive move-start
+   * @param {number} end Inclusive move-end
+   * @param {number} target
+   * @param {number} assocStart >=0 if start should be associated with the right character. See relative-position assoc parameter.
+   * @param {number} assocEnd >= 0 if end should be associated with the right character.
+   */
+  moveRange (start, end, target, assocStart = 1, assocEnd = -1) {
+    if (start <= target && target <= end) {
+      // It doesn't make sense to move a range into the same range (it's basically a no-op).
+      return
+    }
+    if (this.doc !== null) {
+      transact(this.doc, transaction => {
+        const left = createRelativePositionFromTypeIndex(this, start, assocStart)
+        const right = createRelativePositionFromTypeIndex(this, end + 1, assocEnd)
+        useSearchMarker(transaction, this, target, walker => {
+          walker.insertMove(transaction, left, right)
+        })
+      })
+    } else {
+      const content = /** @type {Array<any>} */ (this._prelimContent).splice(start, end - start + 1)
+      ;/** @type {Array<any>} */ (this._prelimContent).splice(target, 0, ...content)
+    }
+  }
+
+  /**
+   * Appends content to this YArray.
+   *
+   * @param {Array<T>} content Array of content to append.
+   */
+  push (content) {
+    this.insert(this.length, content)
+  }
+
+  /**
+   * Preppends content to this YArray.
+   *
+   * @param {Array<T>} content Array of content to preppend.
+   */
+  unshift (content) {
+    this.insert(0, content)
+  }
+
+  /**
+   * Deletes elements starting from an index.
+   *
+   * @param {number} index Index at which to start deleting elements
+   * @param {number} length The number of elements to remove. Defaults to 1.
+   */
+  delete (index, length = 1) {
+    if (this.doc !== null) {
+      transact(this.doc, transaction => {
+        useSearchMarker(transaction, this, index, walker =>
+          walker.delete(transaction, length)
+        )
+      })
+    } else {
+      /** @type {Array<any>} */ (this._prelimContent).splice(index, length)
+    }
+  }
+
+  /**
+   * Returns the i-th element from a YArray.
+   *
+   * @param {number} index The index of the element to return from the YArray
+   * @return {T}
+   */
+  get (index) {
+    return transact(/** @type {Doc} */ (this.doc), transaction =>
+      useSearchMarker(transaction, this, index, walker =>
+        walker.slice(transaction, 1)[0]
+      )
+    )
+  }
+
+  /**
+   * Transforms this YArray to a JavaScript Array.
+   *
+   * @return {Array<T>}
+   */
+  toArray () {
+    return transact(/** @type {Doc} */ (this.doc), tr =>
+      new ListIterator(this).slice(tr, this.length)
+    )
+  }
+
+  /**
+   * Transforms this YArray to a JavaScript Array.
+   *
+   * @param {number} [start]
+   * @param {number} [end]
+   * @return {Array<T>}
+   */
+  slice (start = 0, end = this.length) {
+    return transact(/** @type {Doc} */ (this.doc), transaction =>
+      useSearchMarker(transaction, this, start, walker =>
+        walker.slice(transaction, end < 0 ? this.length + end - start : end - start)
+      )
+    )
+  }
+
+  /**
+   * Transforms this Shared Type to a JSON object.
+   *
+   * @return {Array<any>}
+   */
+  toJSON () {
+    return this.map(c => c instanceof AbstractType ? c.toJSON() : c)
+  }
+
+  /**
+   * Returns an Array with the result of calling a provided function on every
+   * element of this YArray.
+   *
+   * @template M
+   * @param {function(T,number,YArray<T>):M} f Function that produces an element of the new Array
+   * @return {Array<M>} A new array with each element being the result of the
+   *                 callback function
+   */
+  map (f) {
+    return transact(/** @type {Doc} */ (this.doc), tr =>
+      new ListIterator(this).map(tr, f)
+    )
+  }
+
+  /**
+   * Executes a provided function on once on overy element of this YArray.
+   *
+   * @param {function(T,number,YArray<T>):void} f A function to execute on every element of this YArray.
+   */
+  forEach (f) {
+    return transact(/** @type {Doc} */ (this.doc), tr =>
+      new ListIterator(this).forEach(tr, f)
+    )
+  }
+
+  /**
+   * @return {IterableIterator<T>}
+   */
+  [Symbol.iterator] () {
+    return this.toArray().values()
+  }
+
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   */
+  _write (encoder) {
+    encoder.writeTypeRef(YArrayRefID)
+  }
+}
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ *
+ * @private
+ * @function
+ */
+export const readYArray = decoder => new YArray()

src/types/YMap.js

@@ -0,0 +1,269 @@
+
+/**
+ * @module YMap
+ */
+
+import {
+  YEvent,
+  AbstractType,
+  typeMapDelete,
+  typeMapSet,
+  typeMapGet,
+  typeMapHas,
+  createMapIterator,
+  YMapRefID,
+  callTypeObservers,
+  transact,
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, Doc, Transaction, Item // eslint-disable-line
+} from '../internals.js'
+
+import * as iterator from 'lib0/iterator'
+
+/**
+ * @template T
+ * Event that describes the changes on a YMap.
+ */
+export class YMapEvent extends YEvent {
+  /**
+   * @param {YMap<T>} ymap The YArray that changed.
+   * @param {Transaction} transaction
+   * @param {Set<any>} subs The keys that changed.
+   */
+  constructor (ymap, transaction, subs) {
+    super(ymap, transaction)
+    this.keysChanged = subs
+  }
+}
+
+/**
+ * @template MapType
+ * A shared Map implementation.
+ *
+ * @extends AbstractType<YMapEvent<MapType>>
+ * @implements {Iterable<MapType>}
+ */
+export class YMap extends AbstractType {
+  /**
+   *
+   * @param {Iterable<readonly [string, any]>=} entries - an optional iterable to initialize the YMap
+   */
+  constructor (entries) {
+    super()
+    /**
+     * @type {Map<string,any>?}
+     * @private
+     */
+    this._prelimContent = null
+
+    if (entries === undefined) {
+      this._prelimContent = new Map()
+    } else {
+      this._prelimContent = new Map(entries)
+    }
+  }
+
+  /**
+   * Integrate this type into the Yjs instance.
+   *
+   * * Save this struct in the os
+   * * This type is sent to other client
+   * * Observer functions are fired
+   *
+   * @param {Doc} y The Yjs instance
+   * @param {Item} item
+   */
+  _integrate (y, item) {
+    super._integrate(y, item)
+    ;/** @type {Map<string, any>} */ (this._prelimContent).forEach((value, key) => {
+      this.set(key, value)
+    })
+    this._prelimContent = null
+  }
+
+  _copy () {
+    return new YMap()
+  }
+
+  /**
+   * @return {YMap<MapType>}
+   */
+  clone () {
+    const map = new YMap()
+    this.forEach((value, key) => {
+      map.set(key, value instanceof AbstractType ? value.clone() : value)
+    })
+    return map
+  }
+
+  /**
+   * Creates YMapEvent and calls observers.
+   *
+   * @param {Transaction} transaction
+   * @param {Set<null|string>} parentSubs Keys changed on this type. `null` if list was modified.
+   */
+  _callObserver (transaction, parentSubs) {
+    callTypeObservers(this, transaction, new YMapEvent(this, transaction, parentSubs))
+  }
+
+  /**
+   * Transforms this Shared Type to a JSON object.
+   *
+   * @return {Object<string,any>}
+   */
+  toJSON () {
+    /**
+     * @type {Object<string,MapType>}
+     */
+    const map = {}
+    this._map.forEach((item, key) => {
+      if (!item.deleted) {
+        const v = item.content.getContent()[item.length - 1]
+        map[key] = v instanceof AbstractType ? v.toJSON() : v
+      }
+    })
+    return map
+  }
+
+  /**
+   * Returns the size of the YMap (count of key/value pairs)
+   *
+   * @return {number}
+   */
+  get size () {
+    return [...createMapIterator(this._map)].length
+  }
+
+  /**
+   * Returns the keys for each element in the YMap Type.
+   *
+   * @return {IterableIterator<string>}
+   */
+  keys () {
+    return iterator.iteratorMap(createMapIterator(this._map), /** @param {any} v */ v => v[0])
+  }
+
+  /**
+   * Returns the values for each element in the YMap Type.
+   *
+   * @return {IterableIterator<any>}
+   */
+  values () {
+    return iterator.iteratorMap(createMapIterator(this._map), /** @param {any} v */ v => v[1].content.getContent()[v[1].length - 1])
+  }
+
+  /**
+   * Returns an Iterator of [key, value] pairs
+   *
+   * @return {IterableIterator<any>}
+   */
+  entries () {
+    return iterator.iteratorMap(createMapIterator(this._map), /** @param {any} v */ v => [v[0], v[1].content.getContent()[v[1].length - 1]])
+  }
+
+  /**
+   * Executes a provided function on once on every key-value pair.
+   *
+   * @param {function(MapType,string,YMap<MapType>):void} f A function to execute on every element of this YArray.
+   */
+  forEach (f) {
+    /**
+     * @type {Object<string,MapType>}
+     */
+    const map = {}
+    this._map.forEach((item, key) => {
+      if (!item.deleted) {
+        f(item.content.getContent()[item.length - 1], key, this)
+      }
+    })
+    return map
+  }
+
+  /**
+   * @return {IterableIterator<MapType>}
+   */
+  [Symbol.iterator] () {
+    return this.entries()
+  }
+
+  /**
+   * Remove a specified element from this YMap.
+   *
+   * @param {string} key The key of the element to remove.
+   */
+  delete (key) {
+    if (this.doc !== null) {
+      transact(this.doc, transaction => {
+        typeMapDelete(transaction, this, key)
+      })
+    } else {
+      /** @type {Map<string, any>} */ (this._prelimContent).delete(key)
+    }
+  }
+
+  /**
+   * Adds or updates an element with a specified key and value.
+   *
+   * @param {string} key The key of the element to add to this YMap
+   * @param {MapType} value The value of the element to add
+   */
+  set (key, value) {
+    if (this.doc !== null) {
+      transact(this.doc, transaction => {
+        typeMapSet(transaction, this, key, value)
+      })
+    } else {
+      /** @type {Map<string, any>} */ (this._prelimContent).set(key, value)
+    }
+    return value
+  }
+
+  /**
+   * Returns a specified element from this YMap.
+   *
+   * @param {string} key
+   * @return {MapType|undefined}
+   */
+  get (key) {
+    return /** @type {any} */ (typeMapGet(this, key))
+  }
+
+  /**
+   * Returns a boolean indicating whether the specified key exists or not.
+   *
+   * @param {string} key The key to test.
+   * @return {boolean}
+   */
+  has (key) {
+    return typeMapHas(this, key)
+  }
+
+  /**
+   * Removes all elements from this YMap.
+   */
+  clear () {
+    if (this.doc !== null) {
+      transact(this.doc, transaction => {
+        this.forEach(function (value, key, map) {
+          typeMapDelete(transaction, map, key)
+        })
+      })
+    } else {
+      /** @type {Map<string, any>} */ (this._prelimContent).clear()
+    }
+  }
+
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   */
+  _write (encoder) {
+    encoder.writeTypeRef(YMapRefID)
+  }
+}
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ *
+ * @private
+ * @function
+ */
+export const readYMap = decoder => new YMap()

src/types/YXmlElement.js

@@ -0,0 +1,238 @@
+
+import {
+  YXmlFragment,
+  transact,
+  typeMapDelete,
+  typeMapHas,
+  typeMapSet,
+  typeMapGet,
+  typeMapGetAll,
+  typeListForEach,
+  YXmlElementRefID,
+  YXmlText, ContentType, AbstractType, UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, Snapshot, Doc, Item // eslint-disable-line
+} from '../internals.js'
+
+/**
+ * An YXmlElement imitates the behavior of a
+ * {@link https://developer.mozilla.org/en-US/docs/Web/API/Element|Dom Element}.
+ *
+ * * An YXmlElement has attributes (key value pairs)
+ * * An YXmlElement has childElements that must inherit from YXmlElement
+ */
+export class YXmlElement extends YXmlFragment {
+  constructor (nodeName = 'UNDEFINED') {
+    super()
+    this.nodeName = nodeName
+    /**
+     * @type {Map<string, any>|null}
+     */
+    this._prelimAttrs = new Map()
+  }
+
+  /**
+   * @type {YXmlElement|YXmlText|null}
+   */
+  get nextSibling () {
+    const n = this._item ? this._item.next : null
+    return n ? /** @type {YXmlElement|YXmlText} */ (/** @type {ContentType} */ (n.content).type) : null
+  }
+
+  /**
+   * @type {YXmlElement|YXmlText|null}
+   */
+  get prevSibling () {
+    const n = this._item ? this._item.prev : null
+    return n ? /** @type {YXmlElement|YXmlText} */ (/** @type {ContentType} */ (n.content).type) : null
+  }
+
+  /**
+   * Integrate this type into the Yjs instance.
+   *
+   * * Save this struct in the os
+   * * This type is sent to other client
+   * * Observer functions are fired
+   *
+   * @param {Doc} y The Yjs instance
+   * @param {Item} item
+   */
+  _integrate (y, item) {
+    super._integrate(y, item)
+    ;(/** @type {Map<string, any>} */ (this._prelimAttrs)).forEach((value, key) => {
+      this.setAttribute(key, value)
+    })
+    this._prelimAttrs = null
+  }
+
+  /**
+   * Creates an Item with the same effect as this Item (without position effect)
+   *
+   * @return {YXmlElement}
+   */
+  _copy () {
+    return new YXmlElement(this.nodeName)
+  }
+
+  /**
+   * @return {YXmlElement}
+   */
+  clone () {
+    const el = new YXmlElement(this.nodeName)
+    const attrs = this.getAttributes()
+    for (const key in attrs) {
+      el.setAttribute(key, attrs[key])
+    }
+    // @ts-ignore
+    el.insert(0, this.toArray().map(item => item instanceof AbstractType ? item.clone() : item))
+    return el
+  }
+
+  /**
+   * Returns the XML serialization of this YXmlElement.
+   * The attributes are ordered by attribute-name, so you can easily use this
+   * method to compare YXmlElements
+   *
+   * @return {string} The string representation of this type.
+   *
+   * @public
+   */
+  toString () {
+    const attrs = this.getAttributes()
+    const stringBuilder = []
+    const keys = []
+    for (const key in attrs) {
+      keys.push(key)
+    }
+    keys.sort()
+    const keysLen = keys.length
+    for (let i = 0; i < keysLen; i++) {
+      const key = keys[i]
+      stringBuilder.push(key + '="' + attrs[key] + '"')
+    }
+    const nodeName = this.nodeName.toLocaleLowerCase()
+    const attrsString = stringBuilder.length > 0 ? ' ' + stringBuilder.join(' ') : ''
+    return `<${nodeName}${attrsString}>${super.toString()}</${nodeName}>`
+  }
+
+  /**
+   * Removes an attribute from this YXmlElement.
+   *
+   * @param {String} attributeName The attribute name that is to be removed.
+   *
+   * @public
+   */
+  removeAttribute (attributeName) {
+    if (this.doc !== null) {
+      transact(this.doc, transaction => {
+        typeMapDelete(transaction, this, attributeName)
+      })
+    } else {
+      /** @type {Map<string,any>} */ (this._prelimAttrs).delete(attributeName)
+    }
+  }
+
+  /**
+   * Sets or updates an attribute.
+   *
+   * @param {String} attributeName The attribute name that is to be set.
+   * @param {String} attributeValue The attribute value that is to be set.
+   *
+   * @public
+   */
+  setAttribute (attributeName, attributeValue) {
+    if (this.doc !== null) {
+      transact(this.doc, transaction => {
+        typeMapSet(transaction, this, attributeName, attributeValue)
+      })
+    } else {
+      /** @type {Map<string, any>} */ (this._prelimAttrs).set(attributeName, attributeValue)
+    }
+  }
+
+  /**
+   * Returns an attribute value that belongs to the attribute name.
+   *
+   * @param {String} attributeName The attribute name that identifies the
+   *                               queried value.
+   * @return {String} The queried attribute value.
+   *
+   * @public
+   */
+  getAttribute (attributeName) {
+    return /** @type {any} */ (typeMapGet(this, attributeName))
+  }
+
+  /**
+   * Returns whether an attribute exists
+   *
+   * @param {String} attributeName The attribute name to check for existence.
+   * @return {boolean} whether the attribute exists.
+   *
+   * @public
+   */
+  hasAttribute (attributeName) {
+    return /** @type {any} */ (typeMapHas(this, attributeName))
+  }
+
+  /**
+   * Returns all attribute name/value pairs in a JSON Object.
+   *
+   * @param {Snapshot} [snapshot]
+   * @return {Object<string, any>} A JSON Object that describes the attributes.
+   *
+   * @public
+   */
+  getAttributes (snapshot) {
+    return typeMapGetAll(this)
+  }
+
+  /**
+   * Creates a Dom Element that mirrors this YXmlElement.
+   *
+   * @param {Document} [_document=document] The document object (you must define
+   *                                        this when calling this method in
+   *                                        nodejs)
+   * @param {Object<string, any>} [hooks={}] Optional property to customize how hooks
+   *                                             are presented in the DOM
+   * @param {any} [binding] You should not set this property. This is
+   *                               used if DomBinding wants to create a
+   *                               association to the created DOM type.
+   * @return {Node} The {@link https://developer.mozilla.org/en-US/docs/Web/API/Element|Dom Element}
+   *
+   * @public
+   */
+  toDOM (_document = document, hooks = {}, binding) {
+    const dom = _document.createElement(this.nodeName)
+    const attrs = this.getAttributes()
+    for (const key in attrs) {
+      dom.setAttribute(key, attrs[key])
+    }
+    typeListForEach(this, yxml => {
+      dom.appendChild(yxml.toDOM(_document, hooks, binding))
+    })
+    if (binding !== undefined) {
+      binding._createAssociation(dom, this)
+    }
+    return dom
+  }
+
+  /**
+   * Transform the properties of this type to binary and write it to an
+   * BinaryEncoder.
+   *
+   * This is called when this Item is sent to a remote peer.
+   *
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder The encoder to write data to.
+   */
+  _write (encoder) {
+    encoder.writeTypeRef(YXmlElementRefID)
+    encoder.writeKey(this.nodeName)
+  }
+}
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {YXmlElement}
+ *
+ * @function
+ */
+export const readYXmlElement = decoder => new YXmlElement(decoder.readKey())

src/types/YXmlEvent.js

@@ -0,0 +1,39 @@
+
+import {
+  YEvent,
+  YXmlText, YXmlElement, YXmlFragment, Transaction // eslint-disable-line
+} from '../internals.js'
+
+/**
+ * An Event that describes changes on a YXml Element or Yxml Fragment
+ */
+export class YXmlEvent extends YEvent {
+  /**
+   * @param {YXmlElement|YXmlText|YXmlFragment} target The target on which the event is created.
+   * @param {Set<string|null>} subs The set of changed attributes. `null` is included if the
+   *                   child list changed.
+   * @param {Transaction} transaction The transaction instance with wich the
+   *                                  change was created.
+   */
+  constructor (target, subs, transaction) {
+    super(target, transaction)
+    /**
+     * Whether the children changed.
+     * @type {Boolean}
+     * @private
+     */
+    this.childListChanged = false
+    /**
+     * Set of all changed attributes.
+     * @type {Set<string>}
+     */
+    this.attributesChanged = new Set()
+    subs.forEach((sub) => {
+      if (sub === null) {
+        this.childListChanged = true
+      } else {
+        this.attributesChanged.add(sub)
+      }
+    })
+  }
+}

src/types/YXmlFragment.js

@@ -0,0 +1,433 @@
+/**
+ * @module YXml
+ */
+
+import {
+  YXmlEvent,
+  YXmlElement,
+  AbstractType,
+  typeListMap,
+  typeListForEach,
+  typeListInsertGenericsAfter,
+  typeListToArray,
+  YXmlFragmentRefID,
+  callTypeObservers,
+  transact,
+  typeListSlice,
+  useSearchMarker,
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, Doc, ContentType, Transaction, Item, YXmlText, YXmlHook, Snapshot // eslint-disable-line
+} from '../internals.js'
+
+import * as error from 'lib0/error'
+
+/**
+ * Define the elements to which a set of CSS queries apply.
+ * {@link https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Selectors|CSS_Selectors}
+ *
+ * @example
+ *   query = '.classSelector'
+ *   query = 'nodeSelector'
+ *   query = '#idSelector'
+ *
+ * @typedef {string} CSS_Selector
+ */
+
+/**
+ * Dom filter function.
+ *
+ * @callback domFilter
+ * @param {string} nodeName The nodeName of the element
+ * @param {Map} attributes The map of attributes.
+ * @return {boolean} Whether to include the Dom node in the YXmlElement.
+ */
+
+/**
+ * Represents a subset of the nodes of a YXmlElement / YXmlFragment and a
+ * position within them.
+ *
+ * Can be created with {@link YXmlFragment#createTreeWalker}
+ *
+ * @public
+ * @implements {Iterable<YXmlElement|YXmlText|YXmlElement|YXmlHook>}
+ */
+export class YXmlTreeWalker {
+  /**
+   * @param {YXmlFragment | YXmlElement} root
+   * @param {function(AbstractType<any>):boolean} [f]
+   */
+  constructor (root, f = () => true) {
+    this._filter = f
+    this._root = root
+    /**
+     * @type {Item}
+     */
+    this._currentNode = /** @type {Item} */ (root._start)
+    this._firstCall = true
+  }
+
+  [Symbol.iterator] () {
+    return this
+  }
+
+  /**
+   * Get the next node.
+   *
+   * @return {IteratorResult<YXmlElement|YXmlText|YXmlHook>} The next node.
+   *
+   * @public
+   */
+  next () {
+    /**
+     * @type {Item|null}
+     */
+    let n = this._currentNode
+    let type = n && n.content && /** @type {any} */ (n.content).type
+    if (n !== null && (!this._firstCall || n.deleted || !this._filter(type))) { // if first call, we check if we can use the first item
+      do {
+        type = /** @type {any} */ (n.content).type
+        if (!n.deleted && (type.constructor === YXmlElement || type.constructor === YXmlFragment) && type._start !== null) {
+          // walk down in the tree
+          n = type._start
+        } else {
+          // walk right or up in the tree
+          while (n !== null) {
+            if (n.right !== null) {
+              n = n.right
+              break
+            } else if (n.parent === this._root) {
+              n = null
+            } else {
+              n = /** @type {AbstractType<any>} */ (n.parent)._item
+            }
+          }
+        }
+      } while (n !== null && (n.deleted || !this._filter(/** @type {ContentType} */ (n.content).type)))
+    }
+    this._firstCall = false
+    if (n === null) {
+      // @ts-ignore
+      return { value: undefined, done: true }
+    }
+    this._currentNode = n
+    return { value: /** @type {any} */ (n.content).type, done: false }
+  }
+}
+
+/**
+ * Represents a list of {@link YXmlElement}.and {@link YXmlText} types.
+ * A YxmlFragment is similar to a {@link YXmlElement}, but it does not have a
+ * nodeName and it does not have attributes. Though it can be bound to a DOM
+ * element - in this case the attributes and the nodeName are not shared.
+ *
+ * @public
+ * @extends AbstractType<YXmlEvent>
+ */
+export class YXmlFragment extends AbstractType {
+  constructor () {
+    super()
+    /**
+     * @type {Array<any>|null}
+     */
+    this._prelimContent = []
+  }
+
+  /**
+   * @type {YXmlElement|YXmlText|null}
+   */
+  get firstChild () {
+    const first = this._first
+    return first ? first.content.getContent()[0] : null
+  }
+
+  /**
+   * Integrate this type into the Yjs instance.
+   *
+   * * Save this struct in the os
+   * * This type is sent to other client
+   * * Observer functions are fired
+   *
+   * @param {Doc} y The Yjs instance
+   * @param {Item} item
+   */
+  _integrate (y, item) {
+    super._integrate(y, item)
+    this.insert(0, /** @type {Array<any>} */ (this._prelimContent))
+    this._prelimContent = null
+  }
+
+  _copy () {
+    return new YXmlFragment()
+  }
+
+  /**
+   * @return {YXmlFragment}
+   */
+  clone () {
+    const el = new YXmlFragment()
+    // @ts-ignore
+    el.insert(0, this.toArray().map(item => item instanceof AbstractType ? item.clone() : item))
+    return el
+  }
+
+  get length () {
+    return this._prelimContent === null ? this._length : this._prelimContent.length
+  }
+
+  /**
+   * Create a subtree of childNodes.
+   *
+   * @example
+   * const walker = elem.createTreeWalker(dom => dom.nodeName === 'div')
+   * for (let node in walker) {
+   *   // `node` is a div node
+   *   nop(node)
+   * }
+   *
+   * @param {function(AbstractType<any>):boolean} filter Function that is called on each child element and
+   *                          returns a Boolean indicating whether the child
+   *                          is to be included in the subtree.
+   * @return {YXmlTreeWalker} A subtree and a position within it.
+   *
+   * @public
+   */
+  createTreeWalker (filter) {
+    return new YXmlTreeWalker(this, filter)
+  }
+
+  /**
+   * Returns the first YXmlElement that matches the query.
+   * Similar to DOM's {@link querySelector}.
+   *
+   * Query support:
+   *   - tagname
+   * TODO:
+   *   - id
+   *   - attribute
+   *
+   * @param {CSS_Selector} query The query on the children.
+   * @return {YXmlElement|YXmlText|YXmlHook|null} The first element that matches the query or null.
+   *
+   * @public
+   */
+  querySelector (query) {
+    query = query.toUpperCase()
+    // @ts-ignore
+    const iterator = new YXmlTreeWalker(this, element => element.nodeName && element.nodeName.toUpperCase() === query)
+    const next = iterator.next()
+    if (next.done) {
+      return null
+    } else {
+      return next.value
+    }
+  }
+
+  /**
+   * Returns all YXmlElements that match the query.
+   * Similar to Dom's {@link querySelectorAll}.
+   *
+   * @todo Does not yet support all queries. Currently only query by tagName.
+   *
+   * @param {CSS_Selector} query The query on the children
+   * @return {Array<YXmlElement|YXmlText|YXmlHook|null>} The elements that match this query.
+   *
+   * @public
+   */
+  querySelectorAll (query) {
+    query = query.toUpperCase()
+    // @ts-ignore
+    return Array.from(new YXmlTreeWalker(this, element => element.nodeName && element.nodeName.toUpperCase() === query))
+  }
+
+  /**
+   * Creates YXmlEvent and calls observers.
+   *
+   * @param {Transaction} transaction
+   * @param {Set<null|string>} parentSubs Keys changed on this type. `null` if list was modified.
+   */
+  _callObserver (transaction, parentSubs) {
+    callTypeObservers(this, transaction, new YXmlEvent(this, parentSubs, transaction))
+  }
+
+  /**
+   * Get the string representation of all the children of this YXmlFragment.
+   *
+   * @return {string} The string representation of all children.
+   */
+  toString () {
+    return typeListMap(this, xml => xml.toString()).join('')
+  }
+
+  /**
+   * @return {string}
+   */
+  toJSON () {
+    return this.toString()
+  }
+
+  /**
+   * Creates a Dom Element that mirrors this YXmlElement.
+   *
+   * @param {Document} [_document=document] The document object (you must define
+   *                                        this when calling this method in
+   *                                        nodejs)
+   * @param {Object<string, any>} [hooks={}] Optional property to customize how hooks
+   *                                             are presented in the DOM
+   * @param {any} [binding] You should not set this property. This is
+   *                               used if DomBinding wants to create a
+   *                               association to the created DOM type.
+   * @return {Node} The {@link https://developer.mozilla.org/en-US/docs/Web/API/Element|Dom Element}
+   *
+   * @public
+   */
+  toDOM (_document = document, hooks = {}, binding) {
+    const fragment = _document.createDocumentFragment()
+    if (binding !== undefined) {
+      binding._createAssociation(fragment, this)
+    }
+    typeListForEach(this, xmlType => {
+      fragment.insertBefore(xmlType.toDOM(_document, hooks, binding), null)
+    })
+    return fragment
+  }
+
+  /**
+   * Inserts new content at an index.
+   *
+   * @example
+   *  // Insert character 'a' at position 0
+   *  xml.insert(0, [new Y.XmlText('text')])
+   *
+   * @param {number} index The index to insert content at
+   * @param {Array<YXmlElement|YXmlText>} content The array of content
+   */
+  insert (index, content) {
+    if (this.doc !== null) {
+      return transact(/** @type {Doc} */ (this.doc), transaction =>
+        useSearchMarker(transaction, this, index, walker =>
+          walker.insertArrayValue(transaction, content)
+        )
+      )
+    } else {
+      // @ts-ignore _prelimContent is defined because this is not yet integrated
+      this._prelimContent.splice(index, 0, ...content)
+    }
+  }
+
+  /**
+   * Inserts new content at an index.
+   *
+   * @example
+   *  // Insert character 'a' at position 0
+   *  xml.insert(0, [new Y.XmlText('text')])
+   *
+   * @param {null|Item|YXmlElement|YXmlText} ref The index to insert content at
+   * @param {Array<YXmlElement|YXmlText>} content The array of content
+   */
+  insertAfter (ref, content) {
+    if (this.doc !== null) {
+      transact(this.doc, transaction => {
+        const refItem = (ref && ref instanceof AbstractType) ? ref._item : ref
+        typeListInsertGenericsAfter(transaction, this, refItem, content)
+      })
+    } else {
+      const pc = /** @type {Array<any>} */ (this._prelimContent)
+      const index = ref === null ? 0 : pc.findIndex(el => el === ref) + 1
+      if (index === 0 && ref !== null) {
+        throw error.create('Reference item not found')
+      }
+      pc.splice(index, 0, ...content)
+    }
+  }
+
+  /**
+   * Deletes elements starting from an index.
+   *
+   * @param {number} index Index at which to start deleting elements
+   * @param {number} [length=1] The number of elements to remove. Defaults to 1.
+   */
+  delete (index, length = 1) {
+    if (this.doc !== null) {
+      transact(/** @type {Doc} */ (this.doc), transaction =>
+        useSearchMarker(transaction, this, index, walker =>
+          walker.delete(transaction, length)
+        )
+      )
+    } else {
+      // @ts-ignore _prelimContent is defined because this is not yet integrated
+      this._prelimContent.splice(index, length)
+    }
+  }
+
+  /**
+   * Transforms this YArray to a JavaScript Array.
+   *
+   * @return {Array<YXmlElement|YXmlText|YXmlHook>}
+   */
+  toArray () {
+    return typeListToArray(this)
+  }
+
+  /**
+   * Appends content to this YArray.
+   *
+   * @param {Array<YXmlElement|YXmlText>} content Array of content to append.
+   */
+  push (content) {
+    this.insert(this.length, content)
+  }
+
+  /**
+   * Preppends content to this YArray.
+   *
+   * @param {Array<YXmlElement|YXmlText>} content Array of content to preppend.
+   */
+  unshift (content) {
+    this.insert(0, content)
+  }
+
+  /**
+   * Returns the i-th element from a YArray.
+   *
+   * @param {number} index The index of the element to return from the YArray
+   * @return {YXmlElement|YXmlText}
+   */
+  get (index) {
+    return transact(/** @type {Doc} */ (this.doc), transaction =>
+      useSearchMarker(transaction, this, index, walker =>
+        walker.slice(transaction, 1)[0]
+      )
+    )
+  }
+
+  /**
+   * Transforms this YArray to a JavaScript Array.
+   *
+   * @param {number} [start]
+   * @param {number} [end]
+   * @return {Array<YXmlElement|YXmlText>}
+   */
+  slice (start = 0, end = this.length) {
+    return typeListSlice(this, start, end)
+  }
+
+  /**
+   * Transform the properties of this type to binary and write it to an
+   * BinaryEncoder.
+   *
+   * This is called when this Item is sent to a remote peer.
+   *
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder The encoder to write data to.
+   */
+  _write (encoder) {
+    encoder.writeTypeRef(YXmlFragmentRefID)
+  }
+}
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {YXmlFragment}
+ *
+ * @private
+ * @function
+ */
+export const readYXmlFragment = decoder => new YXmlFragment()

src/types/YXmlHook.js

@@ -0,0 +1,95 @@
+
+import {
+  YMap,
+  YXmlHookRefID,
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2 // eslint-disable-line
+} from '../internals.js'
+
+/**
+ * You can manage binding to a custom type with YXmlHook.
+ *
+ * @extends {YMap<any>}
+ */
+export class YXmlHook extends YMap {
+  /**
+   * @param {string} hookName nodeName of the Dom Node.
+   */
+  constructor (hookName) {
+    super()
+    /**
+     * @type {string}
+     */
+    this.hookName = hookName
+  }
+
+  /**
+   * Creates an Item with the same effect as this Item (without position effect)
+   */
+  _copy () {
+    return new YXmlHook(this.hookName)
+  }
+
+  /**
+   * @return {YXmlHook}
+   */
+  clone () {
+    const el = new YXmlHook(this.hookName)
+    this.forEach((value, key) => {
+      el.set(key, value)
+    })
+    return el
+  }
+
+  /**
+   * Creates a Dom Element that mirrors this YXmlElement.
+   *
+   * @param {Document} [_document=document] The document object (you must define
+   *                                        this when calling this method in
+   *                                        nodejs)
+   * @param {Object.<string, any>} [hooks] Optional property to customize how hooks
+   *                                             are presented in the DOM
+   * @param {any} [binding] You should not set this property. This is
+   *                               used if DomBinding wants to create a
+   *                               association to the created DOM type
+   * @return {Element} The {@link https://developer.mozilla.org/en-US/docs/Web/API/Element|Dom Element}
+   *
+   * @public
+   */
+  toDOM (_document = document, hooks = {}, binding) {
+    const hook = hooks[this.hookName]
+    let dom
+    if (hook !== undefined) {
+      dom = hook.createDom(this)
+    } else {
+      dom = document.createElement(this.hookName)
+    }
+    dom.setAttribute('data-yjs-hook', this.hookName)
+    if (binding !== undefined) {
+      binding._createAssociation(dom, this)
+    }
+    return dom
+  }
+
+  /**
+   * Transform the properties of this type to binary and write it to an
+   * BinaryEncoder.
+   *
+   * This is called when this Item is sent to a remote peer.
+   *
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder The encoder to write data to.
+   */
+  _write (encoder) {
+    encoder.writeTypeRef(YXmlHookRefID)
+    encoder.writeKey(this.hookName)
+  }
+}
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {YXmlHook}
+ *
+ * @private
+ * @function
+ */
+export const readYXmlHook = decoder =>
+  new YXmlHook(decoder.readKey())

src/types/YXmlText.js

@@ -0,0 +1,121 @@
+
+import {
+  YText,
+  YXmlTextRefID,
+  ContentType, YXmlElement, UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, // eslint-disable-line
+} from '../internals.js'
+
+/**
+ * Represents text in a Dom Element. In the future this type will also handle
+ * simple formatting information like bold and italic.
+ */
+export class YXmlText extends YText {
+  /**
+   * @type {YXmlElement|YXmlText|null}
+   */
+  get nextSibling () {
+    const n = this._item ? this._item.next : null
+    return n ? /** @type {YXmlElement|YXmlText} */ (/** @type {ContentType} */ (n.content).type) : null
+  }
+
+  /**
+   * @type {YXmlElement|YXmlText|null}
+   */
+  get prevSibling () {
+    const n = this._item ? this._item.prev : null
+    return n ? /** @type {YXmlElement|YXmlText} */ (/** @type {ContentType} */ (n.content).type) : null
+  }
+
+  _copy () {
+    return new YXmlText()
+  }
+
+  /**
+   * @return {YXmlText}
+   */
+  clone () {
+    const text = new YXmlText()
+    text.applyDelta(this.toDelta())
+    return text
+  }
+
+  /**
+   * Creates a Dom Element that mirrors this YXmlText.
+   *
+   * @param {Document} [_document=document] The document object (you must define
+   *                                        this when calling this method in
+   *                                        nodejs)
+   * @param {Object<string, any>} [hooks] Optional property to customize how hooks
+   *                                             are presented in the DOM
+   * @param {any} [binding] You should not set this property. This is
+   *                               used if DomBinding wants to create a
+   *                               association to the created DOM type.
+   * @return {Text} The {@link https://developer.mozilla.org/en-US/docs/Web/API/Element|Dom Element}
+   *
+   * @public
+   */
+  toDOM (_document = document, hooks, binding) {
+    const dom = _document.createTextNode(this.toString())
+    if (binding !== undefined) {
+      binding._createAssociation(dom, this)
+    }
+    return dom
+  }
+
+  toString () {
+    // @ts-ignore
+    return this.toDelta().map(delta => {
+      const nestedNodes = []
+      for (const nodeName in delta.attributes) {
+        const attrs = []
+        for (const key in delta.attributes[nodeName]) {
+          attrs.push({ key, value: delta.attributes[nodeName][key] })
+        }
+        // sort attributes to get a unique order
+        attrs.sort((a, b) => a.key < b.key ? -1 : 1)
+        nestedNodes.push({ nodeName, attrs })
+      }
+      // sort node order to get a unique order
+      nestedNodes.sort((a, b) => a.nodeName < b.nodeName ? -1 : 1)
+      // now convert to dom string
+      let str = ''
+      for (let i = 0; i < nestedNodes.length; i++) {
+        const node = nestedNodes[i]
+        str += `<${node.nodeName}`
+        for (let j = 0; j < node.attrs.length; j++) {
+          const attr = node.attrs[j]
+          str += ` ${attr.key}="${attr.value}"`
+        }
+        str += '>'
+      }
+      str += delta.insert
+      for (let i = nestedNodes.length - 1; i >= 0; i--) {
+        str += `</${nestedNodes[i].nodeName}>`
+      }
+      return str
+    }).join('')
+  }
+
+  /**
+   * @return {string}
+   */
+  toJSON () {
+    return this.toString()
+  }
+
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   */
+  _write (encoder) {
+    encoder.writeTypeRef(YXmlTextRefID)
+  }
+}
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {YXmlText}
+ *
+ * @private
+ * @function
+ */
+export const readYXmlText = decoder => new YXmlText()

src/utils/AbstractConnector.js

@@ -0,0 +1,26 @@
+
+import { Observable } from 'lib0/observable'
+
+import {
+  Doc // eslint-disable-line
+} from '../internals.js'
+
+/**
+ * This is an abstract interface that all Connectors should implement to keep them interchangeable.
+ *
+ * @note This interface is experimental and it is not advised to actually inherit this class.
+ *       It just serves as typing information.
+ *
+ * @extends {Observable<any>}
+ */
+export class AbstractConnector extends Observable {
+  /**
+   * @param {Doc} ydoc
+   * @param {any} awareness
+   */
+  constructor (ydoc, awareness) {
+    super()
+    this.doc = ydoc
+    this.awareness = awareness
+  }
+}

src/utils/DeleteSet.js

@@ -0,0 +1,326 @@
+
+import {
+  findIndexSS,
+  getState,
+  splitItem,
+  iterateStructs,
+  UpdateEncoderV2,
+  DSDecoderV1, DSEncoderV1, DSDecoderV2, DSEncoderV2, Item, GC, StructStore, Transaction, ID // eslint-disable-line
+} from '../internals.js'
+
+import * as array from 'lib0/array'
+import * as math from 'lib0/math'
+import * as map from 'lib0/map'
+import * as encoding from 'lib0/encoding'
+import * as decoding from 'lib0/decoding'
+
+export class DeleteItem {
+  /**
+   * @param {number} clock
+   * @param {number} len
+   */
+  constructor (clock, len) {
+    /**
+     * @type {number}
+     */
+    this.clock = clock
+    /**
+     * @type {number}
+     */
+    this.len = len
+  }
+}
+
+/**
+ * We no longer maintain a DeleteStore. DeleteSet is a temporary object that is created when needed.
+ * - When created in a transaction, it must only be accessed after sorting, and merging
+ *   - This DeleteSet is send to other clients
+ * - We do not create a DeleteSet when we send a sync message. The DeleteSet message is created directly from StructStore
+ * - We read a DeleteSet as part of a sync/update message. In this case the DeleteSet is already sorted and merged.
+ */
+export class DeleteSet {
+  constructor () {
+    /**
+     * @type {Map<number,Array<DeleteItem>>}
+     */
+    this.clients = new Map()
+  }
+}
+
+/**
+ * Iterate over all structs that the DeleteSet gc's.
+ *
+ * @param {Transaction} transaction
+ * @param {DeleteSet} ds
+ * @param {function(GC|Item):void} f
+ *
+ * @function
+ */
+export const iterateDeletedStructs = (transaction, ds, f) =>
+  ds.clients.forEach((deletes, clientid) => {
+    const structs = /** @type {Array<GC|Item>} */ (transaction.doc.store.clients.get(clientid))
+    for (let i = 0; i < deletes.length; i++) {
+      const del = deletes[i]
+      iterateStructs(transaction, structs, del.clock, del.len, f)
+    }
+  })
+
+/**
+ * @param {Array<DeleteItem>} dis
+ * @param {number} clock
+ * @return {number|null}
+ *
+ * @private
+ * @function
+ */
+export const findIndexDS = (dis, clock) => {
+  let left = 0
+  let right = dis.length - 1
+  while (left <= right) {
+    const midindex = math.floor((left + right) / 2)
+    const mid = dis[midindex]
+    const midclock = mid.clock
+    if (midclock <= clock) {
+      if (clock < midclock + mid.len) {
+        return midindex
+      }
+      left = midindex + 1
+    } else {
+      right = midindex - 1
+    }
+  }
+  return null
+}
+
+/**
+ * @param {DeleteSet} ds
+ * @param {ID} id
+ * @return {boolean}
+ *
+ * @private
+ * @function
+ */
+export const isDeleted = (ds, id) => {
+  const dis = ds.clients.get(id.client)
+  return dis !== undefined && findIndexDS(dis, id.clock) !== null
+}
+
+/**
+ * @param {DeleteSet} ds
+ *
+ * @private
+ * @function
+ */
+export const sortAndMergeDeleteSet = ds => {
+  ds.clients.forEach(dels => {
+    dels.sort((a, b) => a.clock - b.clock)
+    // merge items without filtering or splicing the array
+    // i is the current pointer
+    // j refers to the current insert position for the pointed item
+    // try to merge dels[i] into dels[j-1] or set dels[j]=dels[i]
+    let i, j
+    for (i = 1, j = 1; i < dels.length; i++) {
+      const left = dels[j - 1]
+      const right = dels[i]
+      if (left.clock + left.len >= right.clock) {
+        left.len = math.max(left.len, right.clock + right.len - left.clock)
+      } else {
+        if (j < i) {
+          dels[j] = right
+        }
+        j++
+      }
+    }
+    dels.length = j
+  })
+}
+
+/**
+ * @param {Array<DeleteSet>} dss
+ * @return {DeleteSet} A fresh DeleteSet
+ */
+export const mergeDeleteSets = dss => {
+  const merged = new DeleteSet()
+  for (let dssI = 0; dssI < dss.length; dssI++) {
+    dss[dssI].clients.forEach((delsLeft, client) => {
+      if (!merged.clients.has(client)) {
+        // Write all missing keys from current ds and all following.
+        // If merged already contains `client` current ds has already been added.
+        /**
+         * @type {Array<DeleteItem>}
+         */
+        const dels = delsLeft.slice()
+        for (let i = dssI + 1; i < dss.length; i++) {
+          array.appendTo(dels, dss[i].clients.get(client) || [])
+        }
+        merged.clients.set(client, dels)
+      }
+    })
+  }
+  sortAndMergeDeleteSet(merged)
+  return merged
+}
+
+/**
+ * @param {DeleteSet} ds
+ * @param {number} client
+ * @param {number} clock
+ * @param {number} length
+ *
+ * @private
+ * @function
+ */
+export const addToDeleteSet = (ds, client, clock, length) => {
+  map.setIfUndefined(ds.clients, client, () => []).push(new DeleteItem(clock, length))
+}
+
+export const createDeleteSet = () => new DeleteSet()
+
+/**
+ * @param {StructStore} ss
+ * @return {DeleteSet} Merged and sorted DeleteSet
+ *
+ * @private
+ * @function
+ */
+export const createDeleteSetFromStructStore = ss => {
+  const ds = createDeleteSet()
+  ss.clients.forEach((structs, client) => {
+    /**
+     * @type {Array<DeleteItem>}
+     */
+    const dsitems = []
+    for (let i = 0; i < structs.length; i++) {
+      const struct = structs[i]
+      if (struct.deleted) {
+        const clock = struct.id.clock
+        let len = struct.length
+        if (i + 1 < structs.length) {
+          for (let next = structs[i + 1]; i + 1 < structs.length && next.deleted; next = structs[++i + 1]) {
+            len += next.length
+          }
+        }
+        dsitems.push(new DeleteItem(clock, len))
+      }
+    }
+    if (dsitems.length > 0) {
+      ds.clients.set(client, dsitems)
+    }
+  })
+  return ds
+}
+
+/**
+ * @param {DSEncoderV1 | DSEncoderV2} encoder
+ * @param {DeleteSet} ds
+ *
+ * @private
+ * @function
+ */
+export const writeDeleteSet = (encoder, ds) => {
+  encoding.writeVarUint(encoder.restEncoder, ds.clients.size)
+  ds.clients.forEach((dsitems, client) => {
+    encoder.resetDsCurVal()
+    encoding.writeVarUint(encoder.restEncoder, client)
+    const len = dsitems.length
+    encoding.writeVarUint(encoder.restEncoder, len)
+    for (let i = 0; i < len; i++) {
+      const item = dsitems[i]
+      encoder.writeDsClock(item.clock)
+      encoder.writeDsLen(item.len)
+    }
+  })
+}
+
+/**
+ * @param {DSDecoderV1 | DSDecoderV2} decoder
+ * @return {DeleteSet}
+ *
+ * @private
+ * @function
+ */
+export const readDeleteSet = decoder => {
+  const ds = new DeleteSet()
+  const numClients = decoding.readVarUint(decoder.restDecoder)
+  for (let i = 0; i < numClients; i++) {
+    decoder.resetDsCurVal()
+    const client = decoding.readVarUint(decoder.restDecoder)
+    const numberOfDeletes = decoding.readVarUint(decoder.restDecoder)
+    if (numberOfDeletes > 0) {
+      const dsField = map.setIfUndefined(ds.clients, client, () => [])
+      for (let i = 0; i < numberOfDeletes; i++) {
+        dsField.push(new DeleteItem(decoder.readDsClock(), decoder.readDsLen()))
+      }
+    }
+  }
+  return ds
+}
+
+/**
+ * @todo YDecoder also contains references to String and other Decoders. Would make sense to exchange YDecoder.toUint8Array for YDecoder.DsToUint8Array()..
+ */
+
+/**
+ * @param {DSDecoderV1 | DSDecoderV2} decoder
+ * @param {Transaction} transaction
+ * @param {StructStore} store
+ * @return {Uint8Array|null} Returns a v2 update containing all deletes that couldn't be applied yet; or null if all deletes were applied successfully.
+ *
+ * @private
+ * @function
+ */
+export const readAndApplyDeleteSet = (decoder, transaction, store) => {
+  const unappliedDS = new DeleteSet()
+  const numClients = decoding.readVarUint(decoder.restDecoder)
+  for (let i = 0; i < numClients; i++) {
+    decoder.resetDsCurVal()
+    const client = decoding.readVarUint(decoder.restDecoder)
+    const numberOfDeletes = decoding.readVarUint(decoder.restDecoder)
+    const structs = store.clients.get(client) || []
+    const state = getState(store, client)
+    for (let i = 0; i < numberOfDeletes; i++) {
+      const clock = decoder.readDsClock()
+      const clockEnd = clock + decoder.readDsLen()
+      if (clock < state) {
+        if (state < clockEnd) {
+          addToDeleteSet(unappliedDS, client, state, clockEnd - state)
+        }
+        let index = findIndexSS(structs, clock)
+        /**
+         * We can ignore the case of GC and Delete structs, because we are going to skip them
+         * @type {Item}
+         */
+        // @ts-ignore
+        let struct = structs[index]
+        // split the first item if necessary
+        if (!struct.deleted && struct.id.clock < clock) {
+          structs.splice(index + 1, 0, splitItem(transaction, struct, clock - struct.id.clock))
+          index++ // increase we now want to use the next struct
+        }
+        while (index < structs.length) {
+          // @ts-ignore
+          struct = structs[index++]
+          if (struct.id.clock < clockEnd) {
+            if (!struct.deleted) {
+              if (clockEnd < struct.id.clock + struct.length) {
+                structs.splice(index, 0, splitItem(transaction, struct, clockEnd - struct.id.clock))
+              }
+              struct.delete(transaction)
+            }
+          } else {
+            break
+          }
+        }
+      } else {
+        addToDeleteSet(unappliedDS, client, clock, clockEnd - clock)
+      }
+    }
+  }
+  if (unappliedDS.clients.size > 0) {
+    const ds = new UpdateEncoderV2()
+    encoding.writeVarUint(ds.restEncoder, 0) // encode 0 structs
+    writeDeleteSet(ds, unappliedDS)
+    return ds.toUint8Array()
+  }
+  return null
+}

src/utils/Doc.js

@@ -0,0 +1,290 @@
+/**
+ * @module Y
+ */
+
+import {
+  StructStore,
+  AbstractType,
+  YArray,
+  YText,
+  YMap,
+  YXmlFragment,
+  transact,
+  ContentDoc, Item, Transaction, YEvent // eslint-disable-line
+} from '../internals.js'
+
+import { Observable } from 'lib0/observable'
+import * as random from 'lib0/random'
+import * as map from 'lib0/map'
+import * as array from 'lib0/array'
+import * as promise from 'lib0/promise'
+
+export const generateNewClientId = random.uint32
+
+/**
+ * @typedef {Object} DocOpts
+ * @property {boolean} [DocOpts.gc=true] Disable garbage collection (default: gc=true)
+ * @property {function(Item):boolean} [DocOpts.gcFilter] Will be called before an Item is garbage collected. Return false to keep the Item.
+ * @property {string} [DocOpts.guid] Define a globally unique identifier for this document
+ * @property {string | null} [DocOpts.collectionid] Associate this document with a collection. This only plays a role if your provider has a concept of collection.
+ * @property {any} [DocOpts.meta] Any kind of meta information you want to associate with this document. If this is a subdocument, remote peers will store the meta information as well.
+ * @property {boolean} [DocOpts.autoLoad] If a subdocument, automatically load document. If this is a subdocument, remote peers will load the document as well automatically.
+ * @property {boolean} [DocOpts.shouldLoad] Whether the document should be synced by the provider now. This is toggled to true when you call ydoc.load()
+ */
+
+/**
+ * A Yjs instance handles the state of shared data.
+ * @extends Observable<string>
+ */
+export class Doc extends Observable {
+  /**
+   * @param {DocOpts} [opts] configuration
+   */
+  constructor ({ guid = random.uuidv4(), collectionid = null, gc = true, gcFilter = () => true, meta = null, autoLoad = false, shouldLoad = true } = {}) {
+    super()
+    this.gc = gc
+    this.gcFilter = gcFilter
+    this.clientID = generateNewClientId()
+    this.guid = guid
+    this.collectionid = collectionid
+    /**
+     * @type {Map<string, AbstractType<YEvent>>}
+     */
+    this.share = new Map()
+    this.store = new StructStore()
+    /**
+     * @type {Transaction | null}
+     */
+    this._transaction = null
+    /**
+     * @type {Array<Transaction>}
+     */
+    this._transactionCleanups = []
+    /**
+     * @type {Set<Doc>}
+     */
+    this.subdocs = new Set()
+    /**
+     * If this document is a subdocument - a document integrated into another document - then _item is defined.
+     * @type {Item?}
+     */
+    this._item = null
+    this.shouldLoad = shouldLoad
+    this.autoLoad = autoLoad
+    this.meta = meta
+    this.isLoaded = false
+    this.whenLoaded = promise.create(resolve => {
+      this.on('load', () => {
+        this.isLoaded = true
+        resolve(this)
+      })
+    })
+  }
+
+  /**
+   * Notify the parent document that you request to load data into this subdocument (if it is a subdocument).
+   *
+   * `load()` might be used in the future to request any provider to load the most current data.
+   *
+   * It is safe to call `load()` multiple times.
+   */
+  load () {
+    const item = this._item
+    if (item !== null && !this.shouldLoad) {
+      transact(/** @type {any} */ (item.parent).doc, transaction => {
+        transaction.subdocsLoaded.add(this)
+      }, null, true)
+    }
+    this.shouldLoad = true
+  }
+
+  getSubdocs () {
+    return this.subdocs
+  }
+
+  getSubdocGuids () {
+    return new Set(Array.from(this.subdocs).map(doc => doc.guid))
+  }
+
+  /**
+   * Changes that happen inside of a transaction are bundled. This means that
+   * the observer fires _after_ the transaction is finished and that all changes
+   * that happened inside of the transaction are sent as one message to the
+   * other peers.
+   *
+   * @param {function(Transaction):void} f The function that should be executed as a transaction
+   * @param {any} [origin] Origin of who started the transaction. Will be stored on transaction.origin
+   *
+   * @public
+   */
+  transact (f, origin = null) {
+    transact(this, f, origin)
+  }
+
+  /**
+   * Define a shared data type.
+   *
+   * Multiple calls of `y.get(name, TypeConstructor)` yield the same result
+   * and do not overwrite each other. I.e.
+   * `y.define(name, Y.Array) === y.define(name, Y.Array)`
+   *
+   * After this method is called, the type is also available on `y.share.get(name)`.
+   *
+   * *Best Practices:*
+   * Define all types right after the Yjs instance is created and store them in a separate object.
+   * Also use the typed methods `getText(name)`, `getArray(name)`, ..
+   *
+   * @example
+   *   const y = new Y(..)
+   *   const appState = {
+   *     document: y.getText('document')
+   *     comments: y.getArray('comments')
+   *   }
+   *
+   * @param {string} name
+   * @param {Function} TypeConstructor The constructor of the type definition. E.g. Y.Text, Y.Array, Y.Map, ...
+   * @return {AbstractType<any>} The created type. Constructed with TypeConstructor
+   *
+   * @public
+   */
+  get (name, TypeConstructor = AbstractType) {
+    const type = map.setIfUndefined(this.share, name, () => {
+      // @ts-ignore
+      const t = new TypeConstructor()
+      t._integrate(this, null)
+      return t
+    })
+    const Constr = type.constructor
+    if (TypeConstructor !== AbstractType && Constr !== TypeConstructor) {
+      if (Constr === AbstractType) {
+        // @ts-ignore
+        const t = new TypeConstructor()
+        t._map = type._map
+        type._map.forEach(/** @param {Item?} n */ n => {
+          for (; n !== null; n = n.left) {
+            // @ts-ignore
+            n.parent = t
+          }
+        })
+        t._start = type._start
+        for (let n = t._start; n !== null; n = n.right) {
+          n.parent = t
+        }
+        t._length = type._length
+        this.share.set(name, t)
+        t._integrate(this, null)
+        return t
+      } else {
+        throw new Error(`Type with the name ${name} has already been defined with a different constructor`)
+      }
+    }
+    return type
+  }
+
+  /**
+   * @template T
+   * @param {string} [name]
+   * @return {YArray<T>}
+   *
+   * @public
+   */
+  getArray (name = '') {
+    // @ts-ignore
+    return this.get(name, YArray)
+  }
+
+  /**
+   * @param {string} [name]
+   * @return {YText}
+   *
+   * @public
+   */
+  getText (name = '') {
+    // @ts-ignore
+    return this.get(name, YText)
+  }
+
+  /**
+   * @template T
+   * @param {string} [name]
+   * @return {YMap<T>}
+   *
+   * @public
+   */
+  getMap (name = '') {
+    // @ts-ignore
+    return this.get(name, YMap)
+  }
+
+  /**
+   * @param {string} [name]
+   * @return {YXmlFragment}
+   *
+   * @public
+   */
+  getXmlFragment (name = '') {
+    // @ts-ignore
+    return this.get(name, YXmlFragment)
+  }
+
+  /**
+   * Converts the entire document into a js object, recursively traversing each yjs type
+   * Doesn't log types that have not been defined (using ydoc.getType(..)).
+   *
+   * @deprecated Do not use this method and rather call toJSON directly on the shared types.
+   *
+   * @return {Object<string, any>}
+   */
+  toJSON () {
+    /**
+     * @type {Object<string, any>}
+     */
+    const doc = {}
+
+    this.share.forEach((value, key) => {
+      doc[key] = value.toJSON()
+    })
+
+    return doc
+  }
+
+  /**
+   * Emit `destroy` event and unregister all event handlers.
+   */
+  destroy () {
+    array.from(this.subdocs).forEach(subdoc => subdoc.destroy())
+    const item = this._item
+    if (item !== null) {
+      this._item = null
+      const content = /** @type {ContentDoc} */ (item.content)
+      content.doc = new Doc({ guid: this.guid, ...content.opts, shouldLoad: false })
+      content.doc._item = item
+      transact(/** @type {any} */ (item).parent.doc, transaction => {
+        const doc = content.doc
+        if (!item.deleted) {
+          transaction.subdocsAdded.add(doc)
+        }
+        transaction.subdocsRemoved.add(this)
+      }, null, true)
+    }
+    this.emit('destroyed', [true])
+    this.emit('destroy', [this])
+    super.destroy()
+  }
+
+  /**
+   * @param {string} eventName
+   * @param {function(...any):any} f
+   */
+  on (eventName, f) {
+    super.on(eventName, f)
+  }
+
+  /**
+   * @param {string} eventName
+   * @param {function} f
+   */
+  off (eventName, f) {
+    super.off(eventName, f)
+  }
+}

src/utils/EventHandler.js

@@ -0,0 +1,87 @@
+import * as f from 'lib0/function'
+
+/**
+ * General event handler implementation.
+ *
+ * @template ARG0, ARG1
+ *
+ * @private
+ */
+export class EventHandler {
+  constructor () {
+    /**
+     * @type {Array<function(ARG0, ARG1):void>}
+     */
+    this.l = []
+  }
+}
+
+/**
+ * @template ARG0,ARG1
+ * @returns {EventHandler<ARG0,ARG1>}
+ *
+ * @private
+ * @function
+ */
+export const createEventHandler = () => new EventHandler()
+
+/**
+ * Adds an event listener that is called when
+ * {@link EventHandler#callEventListeners} is called.
+ *
+ * @template ARG0,ARG1
+ * @param {EventHandler<ARG0,ARG1>} eventHandler
+ * @param {function(ARG0,ARG1):void} f The event handler.
+ *
+ * @private
+ * @function
+ */
+export const addEventHandlerListener = (eventHandler, f) =>
+  eventHandler.l.push(f)
+
+/**
+ * Removes an event listener.
+ *
+ * @template ARG0,ARG1
+ * @param {EventHandler<ARG0,ARG1>} eventHandler
+ * @param {function(ARG0,ARG1):void} f The event handler that was added with
+ *                     {@link EventHandler#addEventListener}
+ *
+ * @private
+ * @function
+ */
+export const removeEventHandlerListener = (eventHandler, f) => {
+  const l = eventHandler.l
+  const len = l.length
+  eventHandler.l = l.filter(g => f !== g)
+  if (len === eventHandler.l.length) {
+    console.error('[yjs] Tried to remove event handler that doesn\'t exist.')
+  }
+}
+
+/**
+ * Removes all event listeners.
+ * @template ARG0,ARG1
+ * @param {EventHandler<ARG0,ARG1>} eventHandler
+ *
+ * @private
+ * @function
+ */
+export const removeAllEventHandlerListeners = eventHandler => {
+  eventHandler.l.length = 0
+}
+
+/**
+ * Call all event listeners that were added via
+ * {@link EventHandler#addEventListener}.
+ *
+ * @template ARG0,ARG1
+ * @param {EventHandler<ARG0,ARG1>} eventHandler
+ * @param {ARG0} arg0
+ * @param {ARG1} arg1
+ *
+ * @private
+ * @function
+ */
+export const callEventHandlerListeners = (eventHandler, arg0, arg1) =>
+  f.callAll(eventHandler.l, [arg0, arg1])

src/utils/ID.js

@@ -0,0 +1,90 @@
+
+import { AbstractType } from '../internals.js' // eslint-disable-line
+
+import * as decoding from 'lib0/decoding'
+import * as encoding from 'lib0/encoding'
+import * as error from 'lib0/error'
+
+export class ID {
+  /**
+   * @param {number} client client id
+   * @param {number} clock unique per client id, continuous number
+   */
+  constructor (client, clock) {
+    /**
+     * Client id
+     * @type {number}
+     */
+    this.client = client
+    /**
+     * unique per client id, continuous number
+     * @type {number}
+     */
+    this.clock = clock
+  }
+}
+
+/**
+ * @param {ID | null} a
+ * @param {ID | null} b
+ * @return {boolean}
+ *
+ * @function
+ */
+export const compareIDs = (a, b) => a === b || (a !== null && b !== null && a.client === b.client && a.clock === b.clock)
+
+/**
+ * @param {number} client
+ * @param {number} clock
+ *
+ * @private
+ * @function
+ */
+export const createID = (client, clock) => new ID(client, clock)
+
+/**
+ * @param {encoding.Encoder} encoder
+ * @param {ID} id
+ *
+ * @private
+ * @function
+ */
+export const writeID = (encoder, id) => {
+  encoding.writeVarUint(encoder, id.client)
+  encoding.writeVarUint(encoder, id.clock)
+}
+
+/**
+ * Read ID.
+ * * If first varUint read is 0xFFFFFF a RootID is returned.
+ * * Otherwise an ID is returned
+ *
+ * @param {decoding.Decoder} decoder
+ * @return {ID}
+ *
+ * @private
+ * @function
+ */
+export const readID = decoder =>
+  createID(decoding.readVarUint(decoder), decoding.readVarUint(decoder))
+
+/**
+ * The top types are mapped from y.share.get(keyname) => type.
+ * `type` does not store any information about the `keyname`.
+ * This function finds the correct `keyname` for `type` and throws otherwise.
+ *
+ * @param {AbstractType<any>} type
+ * @return {string}
+ *
+ * @private
+ * @function
+ */
+export const findRootTypeKey = type => {
+  // @ts-ignore _y must be defined, otherwise unexpected case
+  for (const [key, value] of type.doc.share.entries()) {
+    if (value === type) {
+      return key
+    }
+  }
+  throw error.unexpectedCase()
+}

src/utils/ListIterator.js

@@ -0,0 +1,510 @@
+import * as error from 'lib0/error'
+
+import {
+  getItemCleanStart,
+  createID,
+  getMovedCoords,
+  updateMarkerChanges,
+  getState,
+  ContentAny,
+  ContentBinary,
+  ContentType,
+  ContentDoc,
+  Doc,
+  RelativePosition, ID, AbstractContent, ContentMove, Transaction, Item, AbstractType // eslint-disable-line
+} from '../internals.js'
+
+const lengthExceeded = error.create('Length exceeded!')
+
+/**
+ * @todo rename to walker?
+ * @todo check that inserting character one after another always reuses ListIterators
+ */
+export class ListIterator {
+  /**
+   * @param {AbstractType<any>} type
+   */
+  constructor (type) {
+    this.type = type
+    /**
+     * Current index-position
+     */
+    this.index = 0
+    /**
+     * Relative position to the current item (if item.content.length > 1)
+     */
+    this.rel = 0
+    /**
+     * This refers to the current right item, unless reachedEnd is true. Then it refers to the left item.
+     *
+     * @public
+     * @type {Item | null}
+     */
+    this.nextItem = type._start
+    this.reachedEnd = type._start === null
+    /**
+     * @type {Item | null}
+     */
+    this.currMove = null
+    /**
+     * @type {Item | null}
+     */
+    this.currMoveStart = null
+    /**
+     * @type {Item | null}
+     */
+    this.currMoveEnd = null
+    /**
+     * @type {Array<{ start: Item | null, end: Item | null, move: Item }>}
+     */
+    this.movedStack = []
+  }
+
+  clone () {
+    const iter = new ListIterator(this.type)
+    iter.index = this.index
+    iter.rel = this.rel
+    iter.nextItem = this.nextItem
+    iter.reachedEnd = this.reachedEnd
+    iter.currMove = this.currMove
+    iter.currMoveStart = this.currMoveStart
+    iter.currMoveEnd = this.currMoveEnd
+    iter.movedStack = this.movedStack.slice()
+    return iter
+  }
+
+  /**
+   * @type {Item | null}
+   */
+  get left () {
+    if (this.reachedEnd) {
+      return this.nextItem
+    } else {
+      return this.nextItem && this.nextItem.left
+    }
+  }
+
+  /**
+   * @type {Item | null}
+   */
+  get right () {
+    if (this.reachedEnd) {
+      return null
+    } else {
+      return this.nextItem
+    }
+  }
+
+  /**
+   * @param {Transaction} tr
+   * @param {number} index
+   */
+  moveTo (tr, index) {
+    const diff = index - this.index
+    if (diff > 0) {
+      this.forward(tr, diff)
+    } else if (diff < 0) {
+      this.backward(tr, -diff)
+    }
+  }
+
+  /**
+   * @param {Transaction} tr
+   * @param {number} len
+   */
+  forward (tr, len) {
+    if (this.index + len > this.type._length) {
+      throw lengthExceeded
+    }
+    let item = this.nextItem
+    this.index += len
+    if (this.rel) {
+      len += this.rel
+      this.rel = 0
+    }
+    while ((!this.reachedEnd || this.currMove !== null) && (len > 0 || (len === 0 && item && (!item.countable || item.deleted || item === this.currMoveEnd || (this.reachedEnd && this.currMoveEnd === null) || item.moved !== this.currMove)))) {
+      if (item === this.currMoveEnd || (this.currMoveEnd === null && this.reachedEnd && this.currMove)) {
+        item = /** @type {Item} */ (this.currMove) // we iterate to the right after the current condition
+        const { start, end, move } = this.movedStack.pop() || { start: null, end: null, move: null }
+        this.currMove = move
+        this.currMoveStart = start
+        this.currMoveEnd = end
+        this.reachedEnd = false
+      } else if (item === null) {
+        break
+      } else if (item.countable && !item.deleted && item.moved === this.currMove && len > 0) {
+        len -= item.length
+        if (len < 0) {
+          this.rel = item.length + len
+          len = 0
+          break
+        }
+      } else if (item.content.constructor === ContentMove && item.moved === this.currMove) {
+        if (this.currMove) {
+          this.movedStack.push({ start: this.currMoveStart, end: this.currMoveEnd, move: this.currMove })
+        }
+        const { start, end } = getMovedCoords(item.content, tr)
+        this.currMove = item
+        this.currMoveStart = start
+        this.currMoveEnd = end
+        item = start
+        continue
+      }
+      if (item.right) {
+        item = item.right
+      } else {
+        this.reachedEnd = true
+      }
+    }
+    this.index -= len
+    this.nextItem = item
+    return this
+  }
+
+  /**
+   * @param {Transaction} tr
+   */
+  reduceMoves (tr) {
+    let item = this.nextItem
+    if (item !== null) {
+      while (item === this.currMoveStart) {
+        item = /** @type {Item} */ (this.currMove) // we iterate to the left after the current condition
+        const { start, end, move } = this.movedStack.pop() || { start: null, end: null, move: null }
+        this.currMove = move
+        this.currMoveStart = start
+        this.currMoveEnd = end
+      }
+      this.nextItem = item
+    }
+  }
+
+  /**
+   * @param {Transaction} tr
+   * @param {number} len
+   * @return {ListIterator}
+   */
+  backward (tr, len) {
+    if (this.index - len < 0) {
+      throw lengthExceeded
+    }
+    this.index -= len
+    if (this.reachedEnd) {
+      const nextItem = /** @type {Item} */ (this.nextItem)
+      this.rel = nextItem.countable && !nextItem.deleted ? nextItem.length : 0
+      this.reachedEnd = false
+    }
+    if (this.rel >= len) {
+      this.rel -= len
+      return this
+    }
+    let item = this.nextItem && this.nextItem.left
+    if (this.rel) {
+      len -= this.rel
+      this.rel = 0
+    }
+    while (item && len > 0) {
+      if (item.countable && !item.deleted && item.moved === this.currMove) {
+        len -= item.length
+        if (len < 0) {
+          this.rel = -len
+          len = 0
+        }
+        if (len === 0) {
+          break
+        }
+      } else if (item.content.constructor === ContentMove && item.moved === this.currMove) {
+        if (this.currMove) {
+          this.movedStack.push({ start: this.currMoveStart, end: this.currMoveEnd, move: this.currMove })
+        }
+        const { start, end } = getMovedCoords(item.content, tr)
+        this.currMove = item
+        this.currMoveStart = start
+        this.currMoveEnd = end
+        item = start
+        continue
+      }
+      if (item === this.currMoveStart) {
+        item = /** @type {Item} */ (this.currMove) // we iterate to the left after the current condition
+        const { start, end, move } = this.movedStack.pop() || { start: null, end: null, move: null }
+        this.currMove = move
+        this.currMoveStart = start
+        this.currMoveEnd = end
+      }
+      item = item.left
+    }
+    this.nextItem = item
+    return this
+  }
+
+  /**
+   * @template {{length: number}} T
+   * @param {Transaction} tr
+   * @param {number} len
+   * @param {T} value the initial content
+   * @param {function(AbstractContent, number, number):T} slice
+   * @param {function(T, T): T} concat
+   */
+  _slice (tr, len, value, slice, concat) {
+    this.index += len
+    while (len > 0 && !this.reachedEnd) {
+      while (this.nextItem && this.nextItem.countable && !this.reachedEnd && len > 0 && this.nextItem !== this.currMoveEnd) {
+        if (!this.nextItem.deleted && this.nextItem.moved === this.currMove) {
+          const item = this.nextItem
+          const slicedContent = slice(item.content, this.rel, len)
+          len -= slicedContent.length
+          value = concat(value, slicedContent)
+          if (item.length !== slicedContent.length) {
+            if (this.rel + slicedContent.length === item.length) {
+              this.rel = 0
+            } else {
+              this.rel += slicedContent.length
+              continue // do not iterate to item.right
+            }
+          }
+        }
+        if (this.nextItem.right) {
+          this.nextItem = this.nextItem.right
+        } else {
+          this.reachedEnd = true
+        }
+      }
+      if (this.nextItem && (!this.reachedEnd || this.currMove !== null) && len > 0) {
+        this.forward(tr, 0)
+      }
+    }
+    if (len < 0) {
+      this.index -= len
+    }
+    return value
+  }
+
+  /**
+   * @param {Transaction} tr
+   * @param {number} len
+   */
+  delete (tr, len) {
+    const startLength = len
+    const sm = this.type._searchMarker
+    let item = this.nextItem
+    while (len > 0) {
+      while (item && !item.deleted && item.countable && !this.reachedEnd && len > 0 && item.moved === this.currMove && item !== this.currMoveEnd) {
+        if (this.rel > 0) {
+          item = getItemCleanStart(tr, createID(item.id.client, item.id.clock + this.rel))
+          this.rel = 0
+        }
+        if (len < item.length) {
+          getItemCleanStart(tr, createID(item.id.client, item.id.clock + len))
+        }
+        len -= item.length
+        item.delete(tr)
+        if (item.right) {
+          item = item.right
+        } else {
+          this.reachedEnd = true
+        }
+      }
+      if (len > 0) {
+        this.nextItem = item
+        this.forward(tr, 0)
+        item = this.nextItem
+      }
+    }
+    this.nextItem = item
+    if (sm) {
+      updateMarkerChanges(sm, this.index, -startLength + len, this)
+    }
+  }
+
+  /**
+   * @param {Transaction} tr
+   */
+  _splitRel (tr) {
+    if (this.rel > 0) {
+      /**
+       * @type {ID}
+       */
+      const itemid = /** @type {Item} */ (this.nextItem).id
+      this.nextItem = getItemCleanStart(tr, createID(itemid.client, itemid.clock + this.rel))
+      this.rel = 0
+    }
+  }
+
+  /**
+   * Important: you must update markers after calling this method!
+   *
+   * @param {Transaction} tr
+   * @param {Array<AbstractContent>} content
+   */
+  insertContents (tr, content) {
+    this.reduceMoves(tr)
+    this._splitRel(tr)
+    const parent = this.type
+    const store = tr.doc.store
+    const ownClientId = tr.doc.clientID
+    /**
+     * @type {Item | null}
+     */
+    const right = this.right
+
+    /**
+     * @type {Item | null}
+     */
+    let left = this.left
+    content.forEach(c => {
+      left = new Item(createID(ownClientId, getState(store, ownClientId)), left, left && left.lastId, right, right && right.id, parent, null, c)
+      left.integrate(tr, 0)
+    })
+    if (right === null) {
+      this.nextItem = left
+      this.reachedEnd = true
+    } else {
+      this.nextItem = right
+    }
+  }
+
+  /**
+   * @param {Transaction} tr
+   * @param {RelativePosition} start
+   * @param {RelativePosition} end
+   */
+  insertMove (tr, start, end) {
+    this.insertContents(tr, [new ContentMove(start, end, -1)]) // @todo adjust priority
+    // @todo is there a better alrogirthm to update searchmarkers? We could simply remove the markers that are in the updated range.
+    // Also note that searchmarkers are updated in insertContents as well.
+    const sm = this.type._searchMarker
+    if (sm) sm.length = 0
+  }
+
+  /**
+   * @param {Transaction} tr
+   * @param {Array<Object<string,any>|Array<any>|boolean|number|null|string|Uint8Array>} values
+   */
+  insertArrayValue (tr, values) {
+    this._splitRel(tr)
+    const sm = this.type._searchMarker
+    /**
+     * @type {Array<AbstractContent>}
+     */
+    const contents = []
+    /**
+     * @type {Array<Object|Array<any>|number|null>}
+     */
+    let jsonContent = []
+    const packJsonContent = () => {
+      if (jsonContent.length > 0) {
+        contents.push(new ContentAny(jsonContent))
+        jsonContent = []
+      }
+    }
+    values.forEach(c => {
+      if (c === null) {
+        jsonContent.push(c)
+      } else {
+        switch (c.constructor) {
+          case Number:
+          case Object:
+          case Boolean:
+          case Array:
+          case String:
+            jsonContent.push(c)
+            break
+          default:
+            packJsonContent()
+            switch (c.constructor) {
+              case Uint8Array:
+              case ArrayBuffer:
+                contents.push(new ContentBinary(new Uint8Array(/** @type {Uint8Array} */ (c))))
+                break
+              case Doc:
+                contents.push(new ContentDoc(/** @type {Doc} */ (c)))
+                break
+              default:
+                if (c instanceof AbstractType) {
+                  contents.push(new ContentType(c))
+                } else {
+                  throw new Error('Unexpected content type in insert operation')
+                }
+            }
+        }
+      }
+    })
+    packJsonContent()
+    this.insertContents(tr, contents)
+    this.index += values.length
+    if (sm) {
+      updateMarkerChanges(sm, this.index - values.length, values.length, this)
+    }
+  }
+
+  /**
+   * @param {Transaction} tr
+   * @param {number} len
+   */
+  slice (tr, len) {
+    return this._slice(tr, len, [], sliceArrayContent, concatArrayContent)
+  }
+
+  /**
+   * @param {Transaction} tr
+   * @param {function(any, number, any):void} f
+   */
+  forEach (tr, f) {
+    for (const val of this.values(tr)) {
+      f(val, this.index, this.type)
+    }
+  }
+
+  /**
+   * @template T
+   * @param {Transaction} tr
+   * @param {function(any, number, any):T} f
+   * @return {Array<T>}
+   */
+  map (tr, f) {
+    const arr = new Array(this.type._length - this.index)
+    let i = 0
+    for (const val of this.values(tr)) {
+      arr[i++] = f(val, this.index, this.type)
+    }
+    return arr
+  }
+
+  /**
+   * @param {Transaction} tr
+   */
+  values (tr) {
+    return {
+      [Symbol.iterator] () {
+        return this
+      },
+      next: () => {
+        if (this.reachedEnd || this.index === this.type._length) {
+          return { done: true }
+        }
+        const [value] = this.slice(tr, 1)
+        return {
+          done: false,
+          value: value
+        }
+      }
+    }
+  }
+}
+
+/**
+ * @param {AbstractContent} itemcontent
+ * @param {number} start
+ * @param {number} len
+ */
+const sliceArrayContent = (itemcontent, start, len) => {
+  const content = itemcontent.getContent()
+  return content.length <= len && start === 0 ? content : content.slice(start, start + len)
+}
+/**
+ * @param {Array<any>} content
+ * @param {Array<any>} added
+ */
+const concatArrayContent = (content, added) => {
+  content.push(...added)
+  return content
+}

src/utils/PermanentUserData.js

@@ -0,0 +1,142 @@
+
+import {
+  YArray,
+  YMap,
+  readDeleteSet,
+  writeDeleteSet,
+  createDeleteSet,
+  DSEncoderV1, DSDecoderV1, ID, DeleteSet, YArrayEvent, Transaction, Doc // eslint-disable-line
+} from '../internals.js'
+
+import * as decoding from 'lib0/decoding'
+
+import { mergeDeleteSets, isDeleted } from './DeleteSet.js'
+
+export class PermanentUserData {
+  /**
+   * @param {Doc} doc
+   * @param {YMap<any>} [storeType]
+   */
+  constructor (doc, storeType = doc.getMap('users')) {
+    /**
+     * @type {Map<string,DeleteSet>}
+     */
+    const dss = new Map()
+    this.yusers = storeType
+    this.doc = doc
+    /**
+     * Maps from clientid to userDescription
+     *
+     * @type {Map<number,string>}
+     */
+    this.clients = new Map()
+    this.dss = dss
+    /**
+     * @param {YMap<any>} user
+     * @param {string} userDescription
+     */
+    const initUser = (user, userDescription) => {
+      /**
+       * @type {YArray<Uint8Array>}
+       */
+      const ds = user.get('ds')
+      const ids = user.get('ids')
+      const addClientId = /** @param {number} clientid */ clientid => this.clients.set(clientid, userDescription)
+      ds.observe(/** @param {YArrayEvent<any>} event */ event => {
+        event.changes.added.forEach(item => {
+          item.content.getContent().forEach(encodedDs => {
+            if (encodedDs instanceof Uint8Array) {
+              this.dss.set(userDescription, mergeDeleteSets([this.dss.get(userDescription) || createDeleteSet(), readDeleteSet(new DSDecoderV1(decoding.createDecoder(encodedDs)))]))
+            }
+          })
+        })
+      })
+      this.dss.set(userDescription, mergeDeleteSets(ds.map(encodedDs => readDeleteSet(new DSDecoderV1(decoding.createDecoder(encodedDs))))))
+      ids.observe(/** @param {YArrayEvent<any>} event */ event =>
+        event.changes.added.forEach(item => item.content.getContent().forEach(addClientId))
+      )
+      ids.forEach(addClientId)
+    }
+    // observe users
+    storeType.observe(event => {
+      event.keysChanged.forEach(userDescription =>
+        initUser(storeType.get(userDescription), userDescription)
+      )
+    })
+    // add intial data
+    storeType.forEach(initUser)
+  }
+
+  /**
+   * @param {Doc} doc
+   * @param {number} clientid
+   * @param {string} userDescription
+   * @param {Object} [conf]
+   * @param {function(Transaction, DeleteSet):boolean} [conf.filter]
+   */
+  setUserMapping (doc, clientid, userDescription, { filter = () => true } = {}) {
+    const users = this.yusers
+    let user = users.get(userDescription)
+    if (!user) {
+      user = new YMap()
+      user.set('ids', new YArray())
+      user.set('ds', new YArray())
+      users.set(userDescription, user)
+    }
+    user.get('ids').push([clientid])
+    users.observe(event => {
+      setTimeout(() => {
+        const userOverwrite = users.get(userDescription)
+        if (userOverwrite !== user) {
+          // user was overwritten, port all data over to the next user object
+          // @todo Experiment with Y.Sets here
+          user = userOverwrite
+          // @todo iterate over old type
+          this.clients.forEach((_userDescription, clientid) => {
+            if (userDescription === _userDescription) {
+              user.get('ids').push([clientid])
+            }
+          })
+          const encoder = new DSEncoderV1()
+          const ds = this.dss.get(userDescription)
+          if (ds) {
+            writeDeleteSet(encoder, ds)
+            user.get('ds').push([encoder.toUint8Array()])
+          }
+        }
+      }, 0)
+    })
+    doc.on('afterTransaction', /** @param {Transaction} transaction */ transaction => {
+      setTimeout(() => {
+        const yds = user.get('ds')
+        const ds = transaction.deleteSet
+        if (transaction.local && ds.clients.size > 0 && filter(transaction, ds)) {
+          const encoder = new DSEncoderV1()
+          writeDeleteSet(encoder, ds)
+          yds.push([encoder.toUint8Array()])
+        }
+      })
+    })
+  }
+
+  /**
+   * @param {number} clientid
+   * @return {any}
+   */
+  getUserByClientId (clientid) {
+    return this.clients.get(clientid) || null
+  }
+
+  /**
+   * @param {ID} id
+   * @return {string | null}
+   */
+  getUserByDeletedId (id) {
+    for (const [userDescription, ds] of this.dss.entries()) {
+      if (isDeleted(ds, id)) {
+        return userDescription
+      }
+    }
+    return null
+  }
+}

src/utils/RelativePosition.js

@@ -0,0 +1,331 @@
+
+import {
+  writeID,
+  readID,
+  compareIDs,
+  getState,
+  findRootTypeKey,
+  Item,
+  createID,
+  ContentType,
+  followRedone,
+  transact,
+  useSearchMarker,
+  ID, Doc, AbstractType // eslint-disable-line
+} from '../internals.js'
+
+import * as encoding from 'lib0/encoding'
+import * as decoding from 'lib0/decoding'
+import * as error from 'lib0/error'
+
+/**
+ * A relative position is based on the Yjs model and is not affected by document changes.
+ * E.g. If you place a relative position before a certain character, it will always point to this character.
+ * If you place a relative position at the end of a type, it will always point to the end of the type.
+ *
+ * A numeric position is often unsuited for user selections, because it does not change when content is inserted
+ * before or after.
+ *
+ * ```Insert(0, 'x')('a|bc') = 'xa|bc'``` Where | is the relative position.
+ *
+ * One of the properties must be defined.
+ *
+ * @example
+ *   // Current cursor position is at position 10
+ *   const relativePosition = createRelativePositionFromIndex(yText, 10)
+ *   // modify yText
+ *   yText.insert(0, 'abc')
+ *   yText.delete(3, 10)
+ *   // Compute the cursor position
+ *   const absolutePosition = createAbsolutePositionFromRelativePosition(y, relativePosition)
+ *   absolutePosition.type === yText // => true
+ *   console.log('cursor location is ' + absolutePosition.index) // => cursor location is 3
+ *
+ */
+export class RelativePosition {
+  /**
+   * @param {ID|null} type
+   * @param {string|null} tname
+   * @param {ID|null} item
+   * @param {number} assoc
+   */
+  constructor (type, tname, item, assoc = 0) {
+    /**
+     * @type {ID|null}
+     */
+    this.type = type
+    /**
+     * @type {string|null}
+     */
+    this.tname = tname
+    /**
+     * @type {ID | null}
+     */
+    this.item = item
+    /**
+     * A relative position is associated to a specific character. By default
+     * assoc >= 0, the relative position is associated to the character
+     * after the meant position.
+     * I.e. position 1 in 'ab' is associated to character 'b'.
+     *
+     * If assoc < 0, then the relative position is associated to the caharacter
+     * before the meant position.
+     *
+     * @type {number}
+     */
+    this.assoc = assoc
+  }
+
+  clone () {
+    return new RelativePosition(this.type, this.tname, this.item, this.assoc)
+  }
+}
+
+/**
+ * @param {RelativePosition} rpos
+ * @return {any}
+ */
+export const relativePositionToJSON = rpos => {
+  const json = {}
+  if (rpos.type) {
+    json.type = rpos.type
+  }
+  if (rpos.tname) {
+    json.tname = rpos.tname
+  }
+  if (rpos.item) {
+    json.item = rpos.item
+  }
+  if (rpos.assoc != null) {
+    json.assoc = rpos.assoc
+  }
+  return json
+}
+
+/**
+ * @param {any} json
+ * @return {RelativePosition}
+ *
+ * @function
+ */
+export const createRelativePositionFromJSON = json => new RelativePosition(json.type == null ? null : createID(json.type.client, json.type.clock), json.tname || null, json.item == null ? null : createID(json.item.client, json.item.clock), json.assoc == null ? 0 : json.assoc)
+
+export class AbsolutePosition {
+  /**
+   * @param {AbstractType<any>} type
+   * @param {number} index
+   * @param {number} [assoc]
+   */
+  constructor (type, index, assoc = 0) {
+    /**
+     * @type {AbstractType<any>}
+     */
+    this.type = type
+    /**
+     * @type {number}
+     */
+    this.index = index
+    this.assoc = assoc
+  }
+}
+
+/**
+ * @param {AbstractType<any>} type
+ * @param {number} index
+ * @param {number} [assoc]
+ *
+ * @function
+ */
+export const createAbsolutePosition = (type, index, assoc = 0) => new AbsolutePosition(type, index, assoc)
+
+/**
+ * @param {AbstractType<any>} type
+ * @param {ID|null} item
+ * @param {number} [assoc]
+ *
+ * @function
+ */
+export const createRelativePosition = (type, item, assoc) => {
+  let typeid = null
+  let tname = null
+  if (type._item === null) {
+    tname = findRootTypeKey(type)
+  } else {
+    typeid = createID(type._item.id.client, type._item.id.clock)
+  }
+  return new RelativePosition(typeid, tname, item, assoc)
+}
+
+/**
+ * Create a relativePosition based on a absolute position.
+ *
+ * @param {AbstractType<any>} type The base type (e.g. YText or YArray).
+ * @param {number} index The absolute position.
+ * @param {number} [assoc]
+ * @return {RelativePosition}
+ *
+ * @function
+ */
+export const createRelativePositionFromTypeIndex = (type, index, assoc = 0) => {
+  if (assoc < 0) {
+    // associated to the left character or the beginning of a type, increment index if possible.
+    if (index === 0) {
+      return createRelativePosition(type, null, assoc)
+    }
+    index--
+  }
+  return transact(/** @type {Doc} */ (type.doc), tr =>
+    useSearchMarker(tr, type, index, walker => {
+      if (walker.reachedEnd) {
+        const item = assoc < 0 ? /** @type {Item} */ (walker.nextItem).lastId : null
+        return createRelativePosition(type, item, assoc)
+      } else {
+        const id = /** @type {Item} */ (walker.nextItem).id
+        return createRelativePosition(type, createID(id.client, id.clock + walker.rel), assoc)
+      }
+    })
+  )
+}
+
+/**
+ * @param {encoding.Encoder} encoder
+ * @param {RelativePosition} rpos
+ *
+ * @function
+ */
+export const writeRelativePosition = (encoder, rpos) => {
+  const { type, tname, item, assoc } = rpos
+  if (item !== null) {
+    encoding.writeVarUint(encoder, 0)
+    writeID(encoder, item)
+  } else if (tname !== null) {
+    // case 2: found position at the end of the list and type is stored in y.share
+    encoding.writeUint8(encoder, 1)
+    encoding.writeVarString(encoder, tname)
+  } else if (type !== null) {
+    // case 3: found position at the end of the list and type is attached to an item
+    encoding.writeUint8(encoder, 2)
+    writeID(encoder, type)
+  } else {
+    throw error.unexpectedCase()
+  }
+  encoding.writeVarInt(encoder, assoc)
+  return encoder
+}
+
+/**
+ * @param {RelativePosition} rpos
+ * @return {Uint8Array}
+ */
+export const encodeRelativePosition = rpos => {
+  const encoder = encoding.createEncoder()
+  writeRelativePosition(encoder, rpos)
+  return encoding.toUint8Array(encoder)
+}
+
+/**
+ * @param {decoding.Decoder} decoder
+ * @return {RelativePosition}
+ *
+ * @function
+ */
+export const readRelativePosition = decoder => {
+  let type = null
+  let tname = null
+  let itemID = null
+  switch (decoding.readVarUint(decoder)) {
+    case 0:
+      // case 1: found position somewhere in the linked list
+      itemID = readID(decoder)
+      break
+    case 1:
+      // case 2: found position at the end of the list and type is stored in y.share
+      tname = decoding.readVarString(decoder)
+      break
+    case 2: {
+      // case 3: found position at the end of the list and type is attached to an item
+      type = readID(decoder)
+    }
+  }
+  const assoc = decoding.hasContent(decoder) ? decoding.readVarInt(decoder) : 0
+  return new RelativePosition(type, tname, itemID, assoc)
+}
+
+/**
+ * @param {Uint8Array} uint8Array
+ * @return {RelativePosition}
+ */
+export const decodeRelativePosition = uint8Array => readRelativePosition(decoding.createDecoder(uint8Array))
+
+/**
+ * @param {RelativePosition} rpos
+ * @param {Doc} doc
+ * @return {AbsolutePosition|null}
+ *
+ * @function
+ */
+export const createAbsolutePositionFromRelativePosition = (rpos, doc) => {
+  const store = doc.store
+  const rightID = rpos.item
+  const typeID = rpos.type
+  const tname = rpos.tname
+  const assoc = rpos.assoc
+  let type = null
+  let index = 0
+  if (rightID !== null) {
+    if (getState(store, rightID.client) <= rightID.clock) {
+      return null
+    }
+    const res = followRedone(store, rightID)
+    const right = res.item
+    if (!(right instanceof Item)) {
+      return null
+    }
+    type = /** @type {AbstractType<any>} */ (right.parent)
+    if (type._item === null || !type._item.deleted) {
+      index = (right.deleted || !right.countable) ? 0 : (res.diff + (assoc >= 0 ? 0 : 1)) // adjust position based on left association if necessary
+      let n = right.left
+      while (n !== null) {
+        if (!n.deleted && n.countable) {
+          index += n.length
+        }
+        n = n.left
+      }
+    }
+  } else {
+    if (tname !== null) {
+      type = doc.get(tname)
+    } else if (typeID !== null) {
+      if (getState(store, typeID.client) <= typeID.clock) {
+        // type does not exist yet
+        return null
+      }
+      const { item } = followRedone(store, typeID)
+      if (item instanceof Item && item.content instanceof ContentType) {
+        type = item.content.type
+      } else {
+        // struct is garbage collected
+        return null
+      }
+    } else {
+      throw error.unexpectedCase()
+    }
+    if (assoc >= 0) {
+      index = type._length
+    } else {
+      index = 0
+    }
+  }
+  return createAbsolutePosition(type, index, rpos.assoc)
+}
+
+/**
+ * @param {RelativePosition|null} a
+ * @param {RelativePosition|null} b
+ * @return {boolean}
+ *
+ * @function
+ */
+export const compareRelativePositions = (a, b) => a === b || (
+  a !== null && b !== null && a.tname === b.tname && compareIDs(a.item, b.item) && compareIDs(a.type, b.type) && a.assoc === b.assoc
+)

src/utils/Snapshot.js

@@ -0,0 +1,201 @@
+
+import {
+  isDeleted,
+  createDeleteSetFromStructStore,
+  getStateVector,
+  getItemCleanStart,
+  iterateDeletedStructs,
+  writeDeleteSet,
+  writeStateVector,
+  readDeleteSet,
+  readStateVector,
+  createDeleteSet,
+  createID,
+  getState,
+  findIndexSS,
+  UpdateEncoderV2,
+  applyUpdateV2,
+  DSEncoderV1, DSEncoderV2, DSDecoderV1, DSDecoderV2, Transaction, Doc, DeleteSet, Item // eslint-disable-line
+} from '../internals.js'
+
+import * as map from 'lib0/map'
+import * as set from 'lib0/set'
+import * as decoding from 'lib0/decoding'
+import * as encoding from 'lib0/encoding'
+
+export class Snapshot {
+  /**
+   * @param {DeleteSet} ds
+   * @param {Map<number,number>} sv state map
+   */
+  constructor (ds, sv) {
+    /**
+     * @type {DeleteSet}
+     */
+    this.ds = ds
+    /**
+     * State Map
+     * @type {Map<number,number>}
+     */
+    this.sv = sv
+  }
+}
+
+/**
+ * @param {Snapshot} snap1
+ * @param {Snapshot} snap2
+ * @return {boolean}
+ */
+export const equalSnapshots = (snap1, snap2) => {
+  const ds1 = snap1.ds.clients
+  const ds2 = snap2.ds.clients
+  const sv1 = snap1.sv
+  const sv2 = snap2.sv
+  if (sv1.size !== sv2.size || ds1.size !== ds2.size) {
+    return false
+  }
+  for (const [key, value] of sv1.entries()) {
+    if (sv2.get(key) !== value) {
+      return false
+    }
+  }
+  for (const [client, dsitems1] of ds1.entries()) {
+    const dsitems2 = ds2.get(client) || []
+    if (dsitems1.length !== dsitems2.length) {
+      return false
+    }
+    for (let i = 0; i < dsitems1.length; i++) {
+      const dsitem1 = dsitems1[i]
+      const dsitem2 = dsitems2[i]
+      if (dsitem1.clock !== dsitem2.clock || dsitem1.len !== dsitem2.len) {
+        return false
+      }
+    }
+  }
+  return true
+}
+
+/**
+ * @param {Snapshot} snapshot
+ * @param {DSEncoderV1 | DSEncoderV2} [encoder]
+ * @return {Uint8Array}
+ */
+export const encodeSnapshotV2 = (snapshot, encoder = new DSEncoderV2()) => {
+  writeDeleteSet(encoder, snapshot.ds)
+  writeStateVector(encoder, snapshot.sv)
+  return encoder.toUint8Array()
+}
+
+/**
+ * @param {Snapshot} snapshot
+ * @return {Uint8Array}
+ */
+export const encodeSnapshot = snapshot => encodeSnapshotV2(snapshot, new DSEncoderV1())
+
+/**
+ * @param {Uint8Array} buf
+ * @param {DSDecoderV1 | DSDecoderV2} [decoder]
+ * @return {Snapshot}
+ */
+export const decodeSnapshotV2 = (buf, decoder = new DSDecoderV2(decoding.createDecoder(buf))) => {
+  return new Snapshot(readDeleteSet(decoder), readStateVector(decoder))
+}
+
+/**
+ * @param {Uint8Array} buf
+ * @return {Snapshot}
+ */
+export const decodeSnapshot = buf => decodeSnapshotV2(buf, new DSDecoderV1(decoding.createDecoder(buf)))
+
+/**
+ * @param {DeleteSet} ds
+ * @param {Map<number,number>} sm
+ * @return {Snapshot}
+ */
+export const createSnapshot = (ds, sm) => new Snapshot(ds, sm)
+
+export const emptySnapshot = createSnapshot(createDeleteSet(), new Map())
+
+/**
+ * @param {Doc} doc
+ * @return {Snapshot}
+ */
+export const snapshot = doc => createSnapshot(createDeleteSetFromStructStore(doc.store), getStateVector(doc.store))
+
+/**
+ * @param {Item} item
+ * @param {Snapshot|undefined} snapshot
+ *
+ * @protected
+ * @function
+ */
+export const isVisible = (item, snapshot) => snapshot === undefined
+  ? !item.deleted
+  : snapshot.sv.has(item.id.client) && (snapshot.sv.get(item.id.client) || 0) > item.id.clock && !isDeleted(snapshot.ds, item.id)
+
+/**
+ * @param {Transaction} transaction
+ * @param {Snapshot} snapshot
+ */
+export const splitSnapshotAffectedStructs = (transaction, snapshot) => {
+  const meta = map.setIfUndefined(transaction.meta, splitSnapshotAffectedStructs, set.create)
+  const store = transaction.doc.store
+  // check if we already split for this snapshot
+  if (!meta.has(snapshot)) {
+    snapshot.sv.forEach((clock, client) => {
+      if (clock < getState(store, client)) {
+        getItemCleanStart(transaction, createID(client, clock))
+      }
+    })
+    iterateDeletedStructs(transaction, snapshot.ds, item => {})
+    meta.add(snapshot)
+  }
+}
+
+/**
+ * @param {Doc} originDoc
+ * @param {Snapshot} snapshot
+ * @param {Doc} [newDoc] Optionally, you may define the Yjs document that receives the data from originDoc
+ * @return {Doc}
+ */
+export const createDocFromSnapshot = (originDoc, snapshot, newDoc = new Doc()) => {
+  if (originDoc.gc) {
+    // we should not try to restore a GC-ed document, because some of the restored items might have their content deleted
+    throw new Error('originDoc must not be garbage collected')
+  }
+  const { sv, ds } = snapshot
+
+  const encoder = new UpdateEncoderV2()
+  originDoc.transact(transaction => {
+    let size = 0
+    sv.forEach(clock => {
+      if (clock > 0) {
+        size++
+      }
+    })
+    encoding.writeVarUint(encoder.restEncoder, size)
+    // splitting the structs before writing them to the encoder
+    for (const [client, clock] of sv) {
+      if (clock === 0) {
+        continue
+      }
+      if (clock < getState(originDoc.store, client)) {
+        getItemCleanStart(transaction, createID(client, clock))
+      }
+      const structs = originDoc.store.clients.get(client) || []
+      const lastStructIndex = findIndexSS(structs, clock - 1)
+      // write # encoded structs
+      encoding.writeVarUint(encoder.restEncoder, lastStructIndex + 1)
+      encoder.writeClient(client)
+      // first clock written is 0
+      encoding.writeVarUint(encoder.restEncoder, 0)
+      for (let i = 0; i <= lastStructIndex; i++) {
+        structs[i].write(encoder, 0)
+      }
+    }
+    writeDeleteSet(encoder, ds)
+  })
+
+  applyUpdateV2(newDoc, encoder.toUint8Array(), 'snapshot')
+  return newDoc
+}

src/utils/StructStore.js

@@ -0,0 +1,261 @@
+
+import {
+  GC,
+  splitItem,
+  Transaction, ID, Item, DSDecoderV2 // eslint-disable-line
+} from '../internals.js'
+
+import * as math from 'lib0/math'
+import * as error from 'lib0/error'
+
+export class StructStore {
+  constructor () {
+    /**
+     * @type {Map<number,Array<GC|Item>>}
+     */
+    this.clients = new Map()
+    /**
+     * @type {null | { missing: Map<number, number>, update: Uint8Array }}
+     */
+    this.pendingStructs = null
+    /**
+     * @type {null | Uint8Array}
+     */
+    this.pendingDs = null
+  }
+}
+
+/**
+ * Return the states as a Map<client,clock>.
+ * Note that clock refers to the next expected clock id.
+ *
+ * @param {StructStore} store
+ * @return {Map<number,number>}
+ *
+ * @public
+ * @function
+ */
+export const getStateVector = store => {
+  const sm = new Map()
+  store.clients.forEach((structs, client) => {
+    const struct = structs[structs.length - 1]
+    sm.set(client, struct.id.clock + struct.length)
+  })
+  return sm
+}
+
+/**
+ * @param {StructStore} store
+ * @param {number} client
+ * @return {number}
+ *
+ * @public
+ * @function
+ */
+export const getState = (store, client) => {
+  const structs = store.clients.get(client)
+  if (structs === undefined) {
+    return 0
+  }
+  const lastStruct = structs[structs.length - 1]
+  return lastStruct.id.clock + lastStruct.length
+}
+
+/**
+ * @param {StructStore} store
+ *
+ * @private
+ * @function
+ */
+export const integretyCheck = store => {
+  store.clients.forEach(structs => {
+    for (let i = 1; i < structs.length; i++) {
+      const l = structs[i - 1]
+      const r = structs[i]
+      if (l.id.clock + l.length !== r.id.clock) {
+        throw new Error('StructStore failed integrety check')
+      }
+    }
+  })
+}
+
+/**
+ * @param {StructStore} store
+ * @param {GC|Item} struct
+ *
+ * @private
+ * @function
+ */
+export const addStruct = (store, struct) => {
+  let structs = store.clients.get(struct.id.client)
+  if (structs === undefined) {
+    structs = []
+    store.clients.set(struct.id.client, structs)
+  } else {
+    const lastStruct = structs[structs.length - 1]
+    if (lastStruct.id.clock + lastStruct.length !== struct.id.clock) {
+      throw error.unexpectedCase()
+    }
+  }
+  structs.push(struct)
+}
+
+/**
+ * Perform a binary search on a sorted array
+ * @param {Array<Item|GC>} structs
+ * @param {number} clock
+ * @return {number}
+ *
+ * @private
+ * @function
+ */
+export const findIndexSS = (structs, clock) => {
+  let left = 0
+  let right = structs.length - 1
+  let mid = structs[right]
+  let midclock = mid.id.clock
+  if (midclock === clock) {
+    return right
+  }
+  // @todo does it even make sense to pivot the search?
+  // If a good split misses, it might actually increase the time to find the correct item.
+  // Currently, the only advantage is that search with pivoting might find the item on the first try.
+  let midindex = math.floor((clock / (midclock + mid.length - 1)) * right) // pivoting the search
+  while (left <= right) {
+    mid = structs[midindex]
+    midclock = mid.id.clock
+    if (midclock <= clock) {
+      if (clock < midclock + mid.length) {
+        return midindex
+      }
+      left = midindex + 1
+    } else {
+      right = midindex - 1
+    }
+    midindex = math.floor((left + right) / 2)
+  }
+  // Always check state before looking for a struct in StructStore
+  // Therefore the case of not finding a struct is unexpected
+  throw error.unexpectedCase()
+}
+
+/**
+ * Expects that id is actually in store. This function throws or is an infinite loop otherwise.
+ *
+ * @param {StructStore} store
+ * @param {ID} id
+ * @return {GC|Item}
+ *
+ * @private
+ * @function
+ */
+export const find = (store, id) => {
+  /**
+   * @type {Array<GC|Item>}
+   */
+  // @ts-ignore
+  const structs = store.clients.get(id.client)
+  return structs[findIndexSS(structs, id.clock)]
+}
+
+/**
+ * Expects that id is actually in store. This function throws or is an infinite loop otherwise.
+ * @private
+ * @function
+ */
+export const getItem = /** @type {function(StructStore,ID):Item} */ (find)
+
+/**
+ * @param {Transaction} transaction
+ * @param {Array<Item|GC>} structs
+ * @param {number} clock
+ */
+export const findIndexCleanStart = (transaction, structs, clock) => {
+  const index = findIndexSS(structs, clock)
+  const struct = structs[index]
+  if (struct.id.clock < clock && struct instanceof Item) {
+    structs.splice(index + 1, 0, splitItem(transaction, struct, clock - struct.id.clock))
+    return index + 1
+  }
+  return index
+}
+
+/**
+ * Expects that id is actually in store. This function throws or is an infinite loop otherwise.
+ *
+ * @param {Transaction} transaction
+ * @param {ID} id
+ * @return {Item}
+ *
+ * @private
+ * @function
+ */
+export const getItemCleanStart = (transaction, id) => {
+  const structs = /** @type {Array<Item>} */ (transaction.doc.store.clients.get(id.client))
+  return structs[findIndexCleanStart(transaction, structs, id.clock)]
+}
+
+/**
+ * Expects that id is actually in store. This function throws or is an infinite loop otherwise.
+ *
+ * @param {Transaction} transaction
+ * @param {ID} id
+ * @return {Item}
+ *
+ * @private
+ * @function
+ */
+export const getItemCleanEnd = (transaction, id) => {
+  /**
+   * @type {Array<Item>}
+   */
+  // @ts-ignore
+  const structs = transaction.doc.store.clients.get(id.client)
+  const index = findIndexSS(structs, id.clock)
+  const struct = structs[index]
+  if (id.clock !== struct.id.clock + struct.length - 1 && struct.constructor !== GC) {
+    structs.splice(index + 1, 0, splitItem(transaction, struct, id.clock - struct.id.clock + 1))
+  }
+  return struct
+}
+
+/**
+ * Replace `item` with `newitem` in store
+ * @param {StructStore} store
+ * @param {GC|Item} struct
+ * @param {GC|Item} newStruct
+ *
+ * @private
+ * @function
+ */
+export const replaceStruct = (store, struct, newStruct) => {
+  const structs = /** @type {Array<GC|Item>} */ (store.clients.get(struct.id.client))
+  structs[findIndexSS(structs, struct.id.clock)] = newStruct
+}
+
+/**
+ * Iterate over a range of structs
+ *
+ * @param {Transaction} transaction
+ * @param {Array<Item|GC>} structs
+ * @param {number} clockStart Inclusive start
+ * @param {number} len
+ * @param {function(GC|Item):void} f
+ *
+ * @function
+ */
+export const iterateStructs = (transaction, structs, clockStart, len, f) => {
+  if (len === 0) {
+    return
+  }
+  const clockEnd = clockStart + len
+  let index = findIndexCleanStart(transaction, structs, clockStart)
+  let struct
+  do {
+    struct = structs[index++]
+    if (clockEnd < struct.id.clock + struct.length) {
+      findIndexCleanStart(transaction, structs, clockEnd)
+    }
+    f(struct)
+  } while (index < structs.length && structs[index].id.clock < clockEnd)
+}

src/utils/Transaction.js

@@ -0,0 +1,426 @@
+
+import {
+  getState,
+  writeStructsFromTransaction,
+  writeDeleteSet,
+  DeleteSet,
+  sortAndMergeDeleteSet,
+  getStateVector,
+  findIndexSS,
+  callEventHandlerListeners,
+  Item,
+  generateNewClientId,
+  createID,
+  UpdateEncoderV1, UpdateEncoderV2, GC, StructStore, AbstractType, AbstractStruct, YEvent, Doc // eslint-disable-line
+} from '../internals.js'
+
+import * as map from 'lib0/map'
+import * as math from 'lib0/math'
+import * as set from 'lib0/set'
+import * as logging from 'lib0/logging'
+import { callAll } from 'lib0/function'
+
+/**
+ * A transaction is created for every change on the Yjs model. It is possible
+ * to bundle changes on the Yjs model in a single transaction to
+ * minimize the number on messages sent and the number of observer calls.
+ * If possible the user of this library should bundle as many changes as
+ * possible. Here is an example to illustrate the advantages of bundling:
+ *
+ * @example
+ * const map = y.define('map', YMap)
+ * // Log content when change is triggered
+ * map.observe(() => {
+ *   console.log('change triggered')
+ * })
+ * // Each change on the map type triggers a log message:
+ * map.set('a', 0) // => "change triggered"
+ * map.set('b', 0) // => "change triggered"
+ * // When put in a transaction, it will trigger the log after the transaction:
+ * y.transact(() => {
+ *   map.set('a', 1)
+ *   map.set('b', 1)
+ * }) // => "change triggered"
+ *
+ * @public
+ */
+export class Transaction {
+  /**
+   * @param {Doc} doc
+   * @param {any} origin
+   * @param {boolean} local
+   */
+  constructor (doc, origin, local) {
+    /**
+     * The Yjs instance.
+     * @type {Doc}
+     */
+    this.doc = doc
+    /**
+     * Describes the set of deleted items by ids
+     * @type {DeleteSet}
+     */
+    this.deleteSet = new DeleteSet()
+    /**
+     * Holds the state before the transaction started.
+     * @type {Map<Number,Number>}
+     */
+    this.beforeState = getStateVector(doc.store)
+    /**
+     * Holds the state after the transaction.
+     * @type {Map<Number,Number>}
+     */
+    this.afterState = new Map()
+    /**
+     * All types that were directly modified (property added or child
+     * inserted/deleted). New types are not included in this Set.
+     * Maps from type to parentSubs (`item.parentSub = null` for YArray)
+     * @type {Map<AbstractType<YEvent>,Set<String|null>>}
+     */
+    this.changed = new Map()
+    /**
+     * Stores the events for the types that observe also child elements.
+     * It is mainly used by `observeDeep`.
+     * @type {Map<AbstractType<YEvent>,Array<YEvent>>}
+     */
+    this.changedParentTypes = new Map()
+    /**
+     * @type {Array<AbstractStruct>}
+     */
+    this._mergeStructs = []
+    /**
+     * @type {any}
+     */
+    this.origin = origin
+    /**
+     * Stores meta information on the transaction
+     * @type {Map<any,any>}
+     */
+    this.meta = new Map()
+    /**
+     * Whether this change originates from this doc.
+     * @type {boolean}
+     */
+    this.local = local
+    /**
+     * @type {Set<Doc>}
+     */
+    this.subdocsAdded = new Set()
+    /**
+     * @type {Set<Doc>}
+     */
+    this.subdocsRemoved = new Set()
+    /**
+     * @type {Set<Doc>}
+     */
+    this.subdocsLoaded = new Set()
+    /**
+     * We store the reference that last moved an item.
+     * This is needed to compute the delta when multiple ContentMove move
+     * the same item.
+     *
+     * @type {Map<Item, Item>}
+     */
+    this.prevMoved = new Map()
+  }
+}
+
+/**
+ * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+ * @param {Transaction} transaction
+ * @return {boolean} Whether data was written.
+ */
+export const writeUpdateMessageFromTransaction = (encoder, transaction) => {
+  if (transaction.deleteSet.clients.size === 0 && !map.any(transaction.afterState, (clock, client) => transaction.beforeState.get(client) !== clock)) {
+    return false
+  }
+  sortAndMergeDeleteSet(transaction.deleteSet)
+  writeStructsFromTransaction(encoder, transaction)
+  writeDeleteSet(encoder, transaction.deleteSet)
+  return true
+}
+
+/**
+ * @param {Transaction} transaction
+ *
+ * @private
+ * @function
+ */
+export const nextID = transaction => {
+  const y = transaction.doc
+  return createID(y.clientID, getState(y.store, y.clientID))
+}
+
+/**
+ * If `type.parent` was added in current transaction, `type` technically
+ * did not change, it was just added and we should not fire events for `type`.
+ *
+ * @param {Transaction} transaction
+ * @param {AbstractType<YEvent>} type
+ * @param {string|null} parentSub
+ */
+export const addChangedTypeToTransaction = (transaction, type, parentSub) => {
+  const item = type._item
+  if (item === null || (item.id.clock < (transaction.beforeState.get(item.id.client) || 0) && !item.deleted)) {
+    map.setIfUndefined(transaction.changed, type, set.create).add(parentSub)
+  }
+}
+
+/**
+ * @param {Array<AbstractStruct>} structs
+ * @param {number} pos
+ */
+const tryToMergeWithLeft = (structs, pos) => {
+  const left = structs[pos - 1]
+  const right = structs[pos]
+  if (left.deleted === right.deleted && left.constructor === right.constructor) {
+    if (left.mergeWith(right)) {
+      structs.splice(pos, 1)
+      if (right instanceof Item && right.parentSub !== null && /** @type {AbstractType<any>} */ (right.parent)._map.get(right.parentSub) === right) {
+        /** @type {AbstractType<any>} */ (right.parent)._map.set(right.parentSub, /** @type {Item} */ (left))
+      }
+    }
+  }
+}
+
+/**
+ * @param {DeleteSet} ds
+ * @param {StructStore} store
+ * @param {function(Item):boolean} gcFilter
+ */
+const tryGcDeleteSet = (ds, store, gcFilter) => {
+  for (const [client, deleteItems] of ds.clients.entries()) {
+    const structs = /** @type {Array<GC|Item>} */ (store.clients.get(client))
+    for (let di = deleteItems.length - 1; di >= 0; di--) {
+      const deleteItem = deleteItems[di]
+      const endDeleteItemClock = deleteItem.clock + deleteItem.len
+      for (
+        let si = findIndexSS(structs, deleteItem.clock), struct = structs[si];
+        si < structs.length && struct.id.clock < endDeleteItemClock;
+        struct = structs[++si]
+      ) {
+        const struct = structs[si]
+        if (deleteItem.clock + deleteItem.len <= struct.id.clock) {
+          break
+        }
+        if (struct instanceof Item && struct.deleted && !struct.keep && gcFilter(struct)) {
+          struct.gc(store, false)
+        }
+      }
+    }
+  }
+}
+
+/**
+ * @param {DeleteSet} ds
+ * @param {StructStore} store
+ */
+const tryMergeDeleteSet = (ds, store) => {
+  // try to merge deleted / gc'd items
+  // merge from right to left for better efficiecy and so we don't miss any merge targets
+  ds.clients.forEach((deleteItems, client) => {
+    const structs = /** @type {Array<GC|Item>} */ (store.clients.get(client))
+    for (let di = deleteItems.length - 1; di >= 0; di--) {
+      const deleteItem = deleteItems[di]
+      // start with merging the item next to the last deleted item
+      const mostRightIndexToCheck = math.min(structs.length - 1, 1 + findIndexSS(structs, deleteItem.clock + deleteItem.len - 1))
+      for (
+        let si = mostRightIndexToCheck, struct = structs[si];
+        si > 0 && struct.id.clock >= deleteItem.clock;
+        struct = structs[--si]
+      ) {
+        tryToMergeWithLeft(structs, si)
+      }
+    }
+  })
+}
+
+/**
+ * @param {DeleteSet} ds
+ * @param {StructStore} store
+ * @param {function(Item):boolean} gcFilter
+ */
+export const tryGc = (ds, store, gcFilter) => {
+  tryGcDeleteSet(ds, store, gcFilter)
+  tryMergeDeleteSet(ds, store)
+}
+
+/**
+ * @param {Array<Transaction>} transactionCleanups
+ * @param {number} i
+ */
+const cleanupTransactions = (transactionCleanups, i) => {
+  if (i < transactionCleanups.length) {
+    const transaction = transactionCleanups[i]
+    const doc = transaction.doc
+    const store = doc.store
+    const ds = transaction.deleteSet
+    const mergeStructs = transaction._mergeStructs
+    try {
+      sortAndMergeDeleteSet(ds)
+      transaction.afterState = getStateVector(transaction.doc.store)
+      doc._transaction = null
+      doc.emit('beforeObserverCalls', [transaction, doc])
+      /**
+       * An array of event callbacks.
+       *
+       * Each callback is called even if the other ones throw errors.
+       *
+       * @type {Array<function():void>}
+       */
+      const fs = []
+      // observe events on changed types
+      transaction.changed.forEach((subs, itemtype) =>
+        fs.push(() => {
+          if (itemtype._item === null || !itemtype._item.deleted) {
+            itemtype._callObserver(transaction, subs)
+          }
+        })
+      )
+      fs.push(() => {
+        // deep observe events
+        transaction.changedParentTypes.forEach((events, type) =>
+          fs.push(() => {
+            // We need to think about the possibility that the user transforms the
+            // Y.Doc in the event.
+            if (type._item === null || !type._item.deleted) {
+              events = events
+                .filter(event =>
+                  event.target._item === null || !event.target._item.deleted
+                )
+              events
+                .forEach(event => {
+                  event.currentTarget = type
+                })
+              // sort events by path length so that top-level events are fired first.
+              events
+                .sort((event1, event2) => event1.path.length - event2.path.length)
+              // We don't need to check for events.length
+              // because we know it has at least one element
+              callEventHandlerListeners(type._dEH, events, transaction)
+            }
+          })
+        )
+        fs.push(() => doc.emit('afterTransaction', [transaction, doc]))
+      })
+      callAll(fs, [])
+    } finally {
+      // Replace deleted items with ItemDeleted / GC.
+      // This is where content is actually remove from the Yjs Doc.
+      if (doc.gc) {
+        tryGcDeleteSet(ds, store, doc.gcFilter)
+      }
+      tryMergeDeleteSet(ds, store)
+
+      // on all affected store.clients props, try to merge
+      transaction.afterState.forEach((clock, client) => {
+        const beforeClock = transaction.beforeState.get(client) || 0
+        if (beforeClock !== clock) {
+          const structs = /** @type {Array<GC|Item>} */ (store.clients.get(client))
+          // we iterate from right to left so we can safely remove entries
+          const firstChangePos = math.max(findIndexSS(structs, beforeClock), 1)
+          for (let i = structs.length - 1; i >= firstChangePos; i--) {
+            tryToMergeWithLeft(structs, i)
+          }
+        }
+      })
+      // try to merge mergeStructs
+      // @todo: it makes more sense to transform mergeStructs to a DS, sort it, and merge from right to left
+      //        but at the moment DS does not handle duplicates
+      for (let i = 0; i < mergeStructs.length; i++) {
+        const { client, clock } = mergeStructs[i].id
+        const structs = /** @type {Array<GC|Item>} */ (store.clients.get(client))
+        const replacedStructPos = findIndexSS(structs, clock)
+        if (replacedStructPos + 1 < structs.length) {
+          tryToMergeWithLeft(structs, replacedStructPos + 1)
+        }
+        if (replacedStructPos > 0) {
+          tryToMergeWithLeft(structs, replacedStructPos)
+        }
+      }
+      if (!transaction.local && transaction.afterState.get(doc.clientID) !== transaction.beforeState.get(doc.clientID)) {
+        logging.print(logging.ORANGE, logging.BOLD, '[yjs] ', logging.UNBOLD, logging.RED, 'Changed the client-id because another client seems to be using it.')
+        doc.clientID = generateNewClientId()
+      }
+      // @todo Merge all the transactions into one and provide send the data as a single update message
+      doc.emit('afterTransactionCleanup', [transaction, doc])
+      if (doc._observers.has('update')) {
+        const encoder = new UpdateEncoderV1()
+        const hasContent = writeUpdateMessageFromTransaction(encoder, transaction)
+        if (hasContent) {
+          doc.emit('update', [encoder.toUint8Array(), transaction.origin, doc, transaction])
+        }
+      }
+      if (doc._observers.has('updateV2')) {
+        const encoder = new UpdateEncoderV2()
+        const hasContent = writeUpdateMessageFromTransaction(encoder, transaction)
+        if (hasContent) {
+          doc.emit('updateV2', [encoder.toUint8Array(), transaction.origin, doc, transaction])
+        }
+      }
+      const { subdocsAdded, subdocsLoaded, subdocsRemoved } = transaction
+      if (subdocsAdded.size > 0 || subdocsRemoved.size > 0 || subdocsLoaded.size > 0) {
+        subdocsAdded.forEach(subdoc => {
+          subdoc.clientID = doc.clientID
+          if (subdoc.collectionid == null) {
+            subdoc.collectionid = doc.collectionid
+          }
+          doc.subdocs.add(subdoc)
+        })
+        subdocsRemoved.forEach(subdoc => doc.subdocs.delete(subdoc))
+        doc.emit('subdocs', [{ loaded: subdocsLoaded, added: subdocsAdded, removed: subdocsRemoved }, doc, transaction])
+        subdocsRemoved.forEach(subdoc => subdoc.destroy())
+      }
+
+      if (transactionCleanups.length <= i + 1) {
+        doc._transactionCleanups = []
+        doc.emit('afterAllTransactions', [doc, transactionCleanups])
+      } else {
+        cleanupTransactions(transactionCleanups, i + 1)
+      }
+    }
+  }
+}
+
+/**
+ * Implements the functionality of `y.transact(()=>{..})`
+ *
+ * @template T
+ *
+ * @param {Doc} doc
+ * @param {function(Transaction):T} f
+ * @param {any} [origin=true]
+ * @return {T}
+ *
+ * @function
+ */
+export const transact = (doc, f, origin = null, local = true) => {
+  const transactionCleanups = doc._transactionCleanups
+  let initialCall = false
+  if (doc._transaction === null) {
+    initialCall = true
+    doc._transaction = new Transaction(doc, origin, local)
+    transactionCleanups.push(doc._transaction)
+    if (transactionCleanups.length === 1) {
+      doc.emit('beforeAllTransactions', [doc])
+    }
+    doc.emit('beforeTransaction', [doc._transaction, doc])
+  }
+  let res
+  try {
+    res = f(doc._transaction)
+  } finally {
+    if (initialCall && transactionCleanups[0] === doc._transaction) {
+      // The first transaction ended, now process observer calls.
+      // Observer call may create new transactions for which we need to call the observers and do cleanup.
+      // We don't want to nest these calls, so we execute these calls one after
+      // another.
+      // Also we need to ensure that all cleanups are called, even if the
+      // observes throw errors.
+      // This file is full of hacky try {} finally {} blocks to ensure that an
+      // event can throw errors and also that the cleanup is called.
+      cleanupTransactions(transactionCleanups, 0)
+    }
+  }
+  return res
+}

src/utils/UndoManager.js

@@ -0,0 +1,285 @@
+import {
+  mergeDeleteSets,
+  iterateDeletedStructs,
+  keepItem,
+  transact,
+  createID,
+  redoItem,
+  isParentOf,
+  followRedone,
+  getItemCleanStart,
+  isDeleted,
+  addToDeleteSet,
+  Transaction, Doc, Item, GC, DeleteSet, AbstractType, YEvent // eslint-disable-line
+} from '../internals.js'
+
+import * as time from 'lib0/time'
+import { Observable } from 'lib0/observable'
+
+class StackItem {
+  /**
+   * @param {DeleteSet} deletions
+   * @param {DeleteSet} insertions
+   */
+  constructor (deletions, insertions) {
+    this.insertions = insertions
+    this.deletions = deletions
+    /**
+     * Use this to save and restore metadata like selection range
+     */
+    this.meta = new Map()
+  }
+}
+
+/**
+ * @param {UndoManager} undoManager
+ * @param {Array<StackItem>} stack
+ * @param {string} eventType
+ * @return {StackItem?}
+ */
+const popStackItem = (undoManager, stack, eventType) => {
+  /**
+   * Whether a change happened
+   * @type {StackItem?}
+   */
+  let result = null
+  /**
+   * Keep a reference to the transaction so we can fire the event with the changedParentTypes
+   * @type {any}
+   */
+  let _tr = null
+  const doc = undoManager.doc
+  const scope = undoManager.scope
+  transact(doc, transaction => {
+    while (stack.length > 0 && result === null) {
+      const store = doc.store
+      const stackItem = /** @type {StackItem} */ (stack.pop())
+      /**
+       * @type {Set<Item>}
+       */
+      const itemsToRedo = new Set()
+      /**
+       * @type {Array<Item>}
+       */
+      const itemsToDelete = []
+      let performedChange = false
+      iterateDeletedStructs(transaction, stackItem.insertions, struct => {
+        if (struct instanceof Item) {
+          if (struct.redone !== null) {
+            let { item, diff } = followRedone(store, struct.id)
+            if (diff > 0) {
+              item = getItemCleanStart(transaction, createID(item.id.client, item.id.clock + diff))
+            }
+            struct = item
+          }
+          if (!struct.deleted && scope.some(type => isParentOf(type, /** @type {Item} */ (struct)))) {
+            itemsToDelete.push(struct)
+          }
+        }
+      })
+      iterateDeletedStructs(transaction, stackItem.deletions, struct => {
+        if (
+          struct instanceof Item &&
+          scope.some(type => isParentOf(type, struct)) &&
+          // Never redo structs in stackItem.insertions because they were created and deleted in the same capture interval.
+          !isDeleted(stackItem.insertions, struct.id)
+        ) {
+          itemsToRedo.add(struct)
+        }
+      })
+      itemsToRedo.forEach(struct => {
+        performedChange = redoItem(transaction, struct, itemsToRedo, itemsToDelete) !== null || performedChange
+      })
+      // We want to delete in reverse order so that children are deleted before
+      // parents, so we have more information available when items are filtered.
+      for (let i = itemsToDelete.length - 1; i >= 0; i--) {
+        const item = itemsToDelete[i]
+        if (undoManager.deleteFilter(item)) {
+          item.delete(transaction)
+          performedChange = true
+        }
+      }
+      result = performedChange ? stackItem : null
+    }
+    transaction.changed.forEach((subProps, type) => {
+      // destroy search marker if necessary
+      if (subProps.has(null) && type._searchMarker) {
+        type._searchMarker.length = 0
+      }
+    })
+    _tr = transaction
+  }, undoManager)
+  if (result != null) {
+    const changedParentTypes = _tr.changedParentTypes
+    undoManager.emit('stack-item-popped', [{ stackItem: result, type: eventType, changedParentTypes }, undoManager])
+  }
+  return result
+}
+
+/**
+ * @typedef {Object} UndoManagerOptions
+ * @property {number} [UndoManagerOptions.captureTimeout=500]
+ * @property {function(Item):boolean} [UndoManagerOptions.deleteFilter=()=>true] Sometimes
+ * it is necessary to filter whan an Undo/Redo operation can delete. If this
+ * filter returns false, the type/item won't be deleted even it is in the
+ * undo/redo scope.
+ * @property {Set<any>} [UndoManagerOptions.trackedOrigins=new Set([null])]
+ */
+
+/**
+ * Fires 'stack-item-added' event when a stack item was added to either the undo- or
+ * the redo-stack. You may store additional stack information via the
+ * metadata property on `event.stackItem.meta` (it is a `Map` of metadata properties).
+ * Fires 'stack-item-popped' event when a stack item was popped from either the
+ * undo- or the redo-stack. You may restore the saved stack information from `event.stackItem.meta`.
+ *
+ * @extends {Observable<'stack-item-added'|'stack-item-popped'>}
+ */
+export class UndoManager extends Observable {
+  /**
+   * @param {AbstractType<any>|Array<AbstractType<any>>} typeScope Accepts either a single type, or an array of types
+   * @param {UndoManagerOptions} options
+   */
+  constructor (typeScope, { captureTimeout = 500, deleteFilter = () => true, trackedOrigins = new Set([null]) } = {}) {
+    super()
+    this.scope = typeScope instanceof Array ? typeScope : [typeScope]
+    this.deleteFilter = deleteFilter
+    trackedOrigins.add(this)
+    this.trackedOrigins = trackedOrigins
+    /**
+     * @type {Array<StackItem>}
+     */
+    this.undoStack = []
+    /**
+     * @type {Array<StackItem>}
+     */
+    this.redoStack = []
+    /**
+     * Whether the client is currently undoing (calling UndoManager.undo)
+     *
+     * @type {boolean}
+     */
+    this.undoing = false
+    this.redoing = false
+    this.doc = /** @type {Doc} */ (this.scope[0].doc)
+    this.lastChange = 0
+    this.doc.on('afterTransaction', /** @param {Transaction} transaction */ transaction => {
+      // Only track certain transactions
+      if (!this.scope.some(type => transaction.changedParentTypes.has(type)) || (!this.trackedOrigins.has(transaction.origin) && (!transaction.origin || !this.trackedOrigins.has(transaction.origin.constructor)))) {
+        return
+      }
+      const undoing = this.undoing
+      const redoing = this.redoing
+      const stack = undoing ? this.redoStack : this.undoStack
+      if (undoing) {
+        this.stopCapturing() // next undo should not be appended to last stack item
+      } else if (!redoing) {
+        // neither undoing nor redoing: delete redoStack
+        this.redoStack = []
+      }
+      const insertions = new DeleteSet()
+      transaction.afterState.forEach((endClock, client) => {
+        const startClock = transaction.beforeState.get(client) || 0
+        const len = endClock - startClock
+        if (len > 0) {
+          addToDeleteSet(insertions, client, startClock, len)
+        }
+      })
+      const now = time.getUnixTime()
+      if (now - this.lastChange < captureTimeout && stack.length > 0 && !undoing && !redoing) {
+        // append change to last stack op
+        const lastOp = stack[stack.length - 1]
+        lastOp.deletions = mergeDeleteSets([lastOp.deletions, transaction.deleteSet])
+        lastOp.insertions = mergeDeleteSets([lastOp.insertions, insertions])
+      } else {
+        // create a new stack op
+        stack.push(new StackItem(transaction.deleteSet, insertions))
+      }
+      if (!undoing && !redoing) {
+        this.lastChange = now
+      }
+      // make sure that deleted structs are not gc'd
+      iterateDeletedStructs(transaction, transaction.deleteSet, /** @param {Item|GC} item */ item => {
+        if (item instanceof Item && this.scope.some(type => isParentOf(type, item))) {
+          keepItem(item, true)
+        }
+      })
+      this.emit('stack-item-added', [{ stackItem: stack[stack.length - 1], origin: transaction.origin, type: undoing ? 'redo' : 'undo', changedParentTypes: transaction.changedParentTypes }, this])
+    })
+  }
+
+  clear () {
+    this.doc.transact(transaction => {
+      /**
+       * @param {StackItem} stackItem
+       */
+      const clearItem = stackItem => {
+        iterateDeletedStructs(transaction, stackItem.deletions, item => {
+          if (item instanceof Item && this.scope.some(type => isParentOf(type, item))) {
+            keepItem(item, false)
+          }
+        })
+      }
+      this.undoStack.forEach(clearItem)
+      this.redoStack.forEach(clearItem)
+    })
+    this.undoStack = []
+    this.redoStack = []
+  }
+
+  /**
+   * UndoManager merges Undo-StackItem if they are created within time-gap
+   * smaller than `options.captureTimeout`. Call `um.stopCapturing()` so that the next
+   * StackItem won't be merged.
+   *
+   *
+   * @example
+   *     // without stopCapturing
+   *     ytext.insert(0, 'a')
+   *     ytext.insert(1, 'b')
+   *     um.undo()
+   *     ytext.toString() // => '' (note that 'ab' was removed)
+   *     // with stopCapturing
+   *     ytext.insert(0, 'a')
+   *     um.stopCapturing()
+   *     ytext.insert(0, 'b')
+   *     um.undo()
+   *     ytext.toString() // => 'a' (note that only 'b' was removed)
+   *
+   */
+  stopCapturing () {
+    this.lastChange = 0
+  }
+
+  /**
+   * Undo last changes on type.
+   *
+   * @return {StackItem?} Returns StackItem if a change was applied
+   */
+  undo () {
+    this.undoing = true
+    let res
+    try {
+      res = popStackItem(this, this.undoStack, 'undo')
+    } finally {
+      this.undoing = false
+    }
+    return res
+  }
+
+  /**
+   * Redo last undo operation.
+   *
+   * @return {StackItem?} Returns StackItem if a change was applied
+   */
+  redo () {
+    this.redoing = true
+    let res
+    try {
+      res = popStackItem(this, this.redoStack, 'redo')
+    } finally {
+      this.redoing = false
+    }
+    return res
+  }
+}

src/utils/UpdateDecoder.js

@@ -0,0 +1,281 @@
+import * as buffer from 'lib0/buffer'
+import * as decoding from 'lib0/decoding'
+import {
+  ID, createID
+} from '../internals.js'
+
+export class DSDecoderV1 {
+  /**
+   * @param {decoding.Decoder} decoder
+   */
+  constructor (decoder) {
+    this.restDecoder = decoder
+  }
+
+  resetDsCurVal () {
+    // nop
+  }
+
+  /**
+   * @return {number}
+   */
+  readDsClock () {
+    return decoding.readVarUint(this.restDecoder)
+  }
+
+  /**
+   * @return {number}
+   */
+  readDsLen () {
+    return decoding.readVarUint(this.restDecoder)
+  }
+}
+
+export class UpdateDecoderV1 extends DSDecoderV1 {
+  /**
+   * @return {ID}
+   */
+  readLeftID () {
+    return createID(decoding.readVarUint(this.restDecoder), decoding.readVarUint(this.restDecoder))
+  }
+
+  /**
+   * @return {ID}
+   */
+  readRightID () {
+    return createID(decoding.readVarUint(this.restDecoder), decoding.readVarUint(this.restDecoder))
+  }
+
+  /**
+   * Read the next client id.
+   * Use this in favor of readID whenever possible to reduce the number of objects created.
+   */
+  readClient () {
+    return decoding.readVarUint(this.restDecoder)
+  }
+
+  /**
+   * @return {number} info An unsigned 8-bit integer
+   */
+  readInfo () {
+    return decoding.readUint8(this.restDecoder)
+  }
+
+  /**
+   * @return {string}
+   */
+  readString () {
+    return decoding.readVarString(this.restDecoder)
+  }
+
+  /**
+   * @return {boolean} isKey
+   */
+  readParentInfo () {
+    return decoding.readVarUint(this.restDecoder) === 1
+  }
+
+  /**
+   * @return {number} info An unsigned 8-bit integer
+   */
+  readTypeRef () {
+    return decoding.readVarUint(this.restDecoder)
+  }
+
+  /**
+   * Write len of a struct - well suited for Opt RLE encoder.
+   *
+   * @return {number} len
+   */
+  readLen () {
+    return decoding.readVarUint(this.restDecoder)
+  }
+
+  /**
+   * @return {any}
+   */
+  readAny () {
+    return decoding.readAny(this.restDecoder)
+  }
+
+  /**
+   * @return {Uint8Array}
+   */
+  readBuf () {
+    return buffer.copyUint8Array(decoding.readVarUint8Array(this.restDecoder))
+  }
+
+  /**
+   * Legacy implementation uses JSON parse. We use any-decoding in v2.
+   *
+   * @return {any}
+   */
+  readJSON () {
+    return JSON.parse(decoding.readVarString(this.restDecoder))
+  }
+
+  /**
+   * @return {string}
+   */
+  readKey () {
+    return decoding.readVarString(this.restDecoder)
+  }
+}
+
+export class DSDecoderV2 {
+  /**
+   * @param {decoding.Decoder} decoder
+   */
+  constructor (decoder) {
+    /**
+     * @private
+     */
+    this.dsCurrVal = 0
+    this.restDecoder = decoder
+  }
+
+  resetDsCurVal () {
+    this.dsCurrVal = 0
+  }
+
+  /**
+   * @return {number}
+   */
+  readDsClock () {
+    this.dsCurrVal += decoding.readVarUint(this.restDecoder)
+    return this.dsCurrVal
+  }
+
+  /**
+   * @return {number}
+   */
+  readDsLen () {
+    const diff = decoding.readVarUint(this.restDecoder) + 1
+    this.dsCurrVal += diff
+    return diff
+  }
+}
+
+export class UpdateDecoderV2 extends DSDecoderV2 {
+  /**
+   * @param {decoding.Decoder} decoder
+   */
+  constructor (decoder) {
+    super(decoder)
+    /**
+     * List of cached keys. If the keys[id] does not exist, we read a new key
+     * from stringEncoder and push it to keys.
+     *
+     * @type {Array<string>}
+     */
+    this.keys = []
+    decoding.readVarUint(decoder) // read feature flag - currently unused
+    this.keyClockDecoder = new decoding.IntDiffOptRleDecoder(decoding.readVarUint8Array(decoder))
+    this.clientDecoder = new decoding.UintOptRleDecoder(decoding.readVarUint8Array(decoder))
+    this.leftClockDecoder = new decoding.IntDiffOptRleDecoder(decoding.readVarUint8Array(decoder))
+    this.rightClockDecoder = new decoding.IntDiffOptRleDecoder(decoding.readVarUint8Array(decoder))
+    this.infoDecoder = new decoding.RleDecoder(decoding.readVarUint8Array(decoder), decoding.readUint8)
+    this.stringDecoder = new decoding.StringDecoder(decoding.readVarUint8Array(decoder))
+    this.parentInfoDecoder = new decoding.RleDecoder(decoding.readVarUint8Array(decoder), decoding.readUint8)
+    this.typeRefDecoder = new decoding.UintOptRleDecoder(decoding.readVarUint8Array(decoder))
+    this.lenDecoder = new decoding.UintOptRleDecoder(decoding.readVarUint8Array(decoder))
+  }
+
+  /**
+   * @return {ID}
+   */
+  readLeftID () {
+    return new ID(this.clientDecoder.read(), this.leftClockDecoder.read())
+  }
+
+  /**
+   * @return {ID}
+   */
+  readRightID () {
+    return new ID(this.clientDecoder.read(), this.rightClockDecoder.read())
+  }
+
+  /**
+   * Read the next client id.
+   * Use this in favor of readID whenever possible to reduce the number of objects created.
+   */
+  readClient () {
+    return this.clientDecoder.read()
+  }
+
+  /**
+   * @return {number} info An unsigned 8-bit integer
+   */
+  readInfo () {
+    return /** @type {number} */ (this.infoDecoder.read())
+  }
+
+  /**
+   * @return {string}
+   */
+  readString () {
+    return this.stringDecoder.read()
+  }
+
+  /**
+   * @return {boolean}
+   */
+  readParentInfo () {
+    return this.parentInfoDecoder.read() === 1
+  }
+
+  /**
+   * @return {number} An unsigned 8-bit integer
+   */
+  readTypeRef () {
+    return this.typeRefDecoder.read()
+  }
+
+  /**
+   * Write len of a struct - well suited for Opt RLE encoder.
+   *
+   * @return {number}
+   */
+  readLen () {
+    return this.lenDecoder.read()
+  }
+
+  /**
+   * @return {any}
+   */
+  readAny () {
+    return decoding.readAny(this.restDecoder)
+  }
+
+  /**
+   * @return {Uint8Array}
+   */
+  readBuf () {
+    return decoding.readVarUint8Array(this.restDecoder)
+  }
+
+  /**
+   * This is mainly here for legacy purposes.
+   *
+   * Initial we incoded objects using JSON. Now we use the much faster lib0/any-encoder. This method mainly exists for legacy purposes for the v1 encoder.
+   *
+   * @return {any}
+   */
+  readJSON () {
+    return decoding.readAny(this.restDecoder)
+  }
+
+  /**
+   * @return {string}
+   */
+  readKey () {
+    const keyClock = this.keyClockDecoder.read()
+    if (keyClock < this.keys.length) {
+      return this.keys[keyClock]
+    } else {
+      const key = this.stringDecoder.read()
+      this.keys.push(key)
+      return key
+    }
+  }
+}

src/utils/UpdateEncoder.js

@@ -0,0 +1,307 @@
+
+import * as error from 'lib0/error'
+import * as encoding from 'lib0/encoding'
+
+import {
+  ID // eslint-disable-line
+} from '../internals.js'
+
+export class DSEncoderV1 {
+  constructor () {
+    this.restEncoder = encoding.createEncoder()
+  }
+
+  toUint8Array () {
+    return encoding.toUint8Array(this.restEncoder)
+  }
+
+  resetDsCurVal () {
+    // nop
+  }
+
+  /**
+   * @param {number} clock
+   */
+  writeDsClock (clock) {
+    encoding.writeVarUint(this.restEncoder, clock)
+  }
+
+  /**
+   * @param {number} len
+   */
+  writeDsLen (len) {
+    encoding.writeVarUint(this.restEncoder, len)
+  }
+}
+
+export class UpdateEncoderV1 extends DSEncoderV1 {
+  /**
+   * @param {ID} id
+   */
+  writeLeftID (id) {
+    encoding.writeVarUint(this.restEncoder, id.client)
+    encoding.writeVarUint(this.restEncoder, id.clock)
+  }
+
+  /**
+   * @param {ID} id
+   */
+  writeRightID (id) {
+    encoding.writeVarUint(this.restEncoder, id.client)
+    encoding.writeVarUint(this.restEncoder, id.clock)
+  }
+
+  /**
+   * Use writeClient and writeClock instead of writeID if possible.
+   * @param {number} client
+   */
+  writeClient (client) {
+    encoding.writeVarUint(this.restEncoder, client)
+  }
+
+  /**
+   * @param {number} info An unsigned 8-bit integer
+   */
+  writeInfo (info) {
+    encoding.writeUint8(this.restEncoder, info)
+  }
+
+  /**
+   * @param {string} s
+   */
+  writeString (s) {
+    encoding.writeVarString(this.restEncoder, s)
+  }
+
+  /**
+   * @param {boolean} isYKey
+   */
+  writeParentInfo (isYKey) {
+    encoding.writeVarUint(this.restEncoder, isYKey ? 1 : 0)
+  }
+
+  /**
+   * @param {number} info An unsigned 8-bit integer
+   */
+  writeTypeRef (info) {
+    encoding.writeVarUint(this.restEncoder, info)
+  }
+
+  /**
+   * Write len of a struct - well suited for Opt RLE encoder.
+   *
+   * @param {number} len
+   */
+  writeLen (len) {
+    encoding.writeVarUint(this.restEncoder, len)
+  }
+
+  /**
+   * @param {any} any
+   */
+  writeAny (any) {
+    encoding.writeAny(this.restEncoder, any)
+  }
+
+  /**
+   * @param {Uint8Array} buf
+   */
+  writeBuf (buf) {
+    encoding.writeVarUint8Array(this.restEncoder, buf)
+  }
+
+  /**
+   * @param {any} embed
+   */
+  writeJSON (embed) {
+    encoding.writeVarString(this.restEncoder, JSON.stringify(embed))
+  }
+
+  /**
+   * @param {string} key
+   */
+  writeKey (key) {
+    encoding.writeVarString(this.restEncoder, key)
+  }
+}
+
+export class DSEncoderV2 {
+  constructor () {
+    this.restEncoder = encoding.createEncoder() // encodes all the rest / non-optimized
+    this.dsCurrVal = 0
+  }
+
+  toUint8Array () {
+    return encoding.toUint8Array(this.restEncoder)
+  }
+
+  resetDsCurVal () {
+    this.dsCurrVal = 0
+  }
+
+  /**
+   * @param {number} clock
+   */
+  writeDsClock (clock) {
+    const diff = clock - this.dsCurrVal
+    this.dsCurrVal = clock
+    encoding.writeVarUint(this.restEncoder, diff)
+  }
+
+  /**
+   * @param {number} len
+   */
+  writeDsLen (len) {
+    if (len === 0) {
+      error.unexpectedCase()
+    }
+    encoding.writeVarUint(this.restEncoder, len - 1)
+    this.dsCurrVal += len
+  }
+}
+
+export class UpdateEncoderV2 extends DSEncoderV2 {
+  constructor () {
+    super()
+    /**
+     * @type {Map<string,number>}
+     */
+    this.keyMap = new Map()
+    /**
+     * Refers to the next uniqe key-identifier to me used.
+     * See writeKey method for more information.
+     *
+     * @type {number}
+     */
+    this.keyClock = 0
+    this.keyClockEncoder = new encoding.IntDiffOptRleEncoder()
+    this.clientEncoder = new encoding.UintOptRleEncoder()
+    this.leftClockEncoder = new encoding.IntDiffOptRleEncoder()
+    this.rightClockEncoder = new encoding.IntDiffOptRleEncoder()
+    this.infoEncoder = new encoding.RleEncoder(encoding.writeUint8)
+    this.stringEncoder = new encoding.StringEncoder()
+    this.parentInfoEncoder = new encoding.RleEncoder(encoding.writeUint8)
+    this.typeRefEncoder = new encoding.UintOptRleEncoder()
+    this.lenEncoder = new encoding.UintOptRleEncoder()
+  }
+
+  toUint8Array () {
+    const encoder = encoding.createEncoder()
+    encoding.writeVarUint(encoder, 0) // this is a feature flag that we might use in the future
+    encoding.writeVarUint8Array(encoder, this.keyClockEncoder.toUint8Array())
+    encoding.writeVarUint8Array(encoder, this.clientEncoder.toUint8Array())
+    encoding.writeVarUint8Array(encoder, this.leftClockEncoder.toUint8Array())
+    encoding.writeVarUint8Array(encoder, this.rightClockEncoder.toUint8Array())
+    encoding.writeVarUint8Array(encoder, encoding.toUint8Array(this.infoEncoder))
+    encoding.writeVarUint8Array(encoder, this.stringEncoder.toUint8Array())
+    encoding.writeVarUint8Array(encoder, encoding.toUint8Array(this.parentInfoEncoder))
+    encoding.writeVarUint8Array(encoder, this.typeRefEncoder.toUint8Array())
+    encoding.writeVarUint8Array(encoder, this.lenEncoder.toUint8Array())
+    // @note The rest encoder is appended! (note the missing var)
+    encoding.writeUint8Array(encoder, encoding.toUint8Array(this.restEncoder))
+    return encoding.toUint8Array(encoder)
+  }
+
+  /**
+   * @param {ID} id
+   */
+  writeLeftID (id) {
+    this.clientEncoder.write(id.client)
+    this.leftClockEncoder.write(id.clock)
+  }
+
+  /**
+   * @param {ID} id
+   */
+  writeRightID (id) {
+    this.clientEncoder.write(id.client)
+    this.rightClockEncoder.write(id.clock)
+  }
+
+  /**
+   * @param {number} client
+   */
+  writeClient (client) {
+    this.clientEncoder.write(client)
+  }
+
+  /**
+   * @param {number} info An unsigned 8-bit integer
+   */
+  writeInfo (info) {
+    this.infoEncoder.write(info)
+  }
+
+  /**
+   * @param {string} s
+   */
+  writeString (s) {
+    this.stringEncoder.write(s)
+  }
+
+  /**
+   * @param {boolean} isYKey
+   */
+  writeParentInfo (isYKey) {
+    this.parentInfoEncoder.write(isYKey ? 1 : 0)
+  }
+
+  /**
+   * @param {number} info An unsigned 8-bit integer
+   */
+  writeTypeRef (info) {
+    this.typeRefEncoder.write(info)
+  }
+
+  /**
+   * Write len of a struct - well suited for Opt RLE encoder.
+   *
+   * @param {number} len
+   */
+  writeLen (len) {
+    this.lenEncoder.write(len)
+  }
+
+  /**
+   * @param {any} any
+   */
+  writeAny (any) {
+    encoding.writeAny(this.restEncoder, any)
+  }
+
+  /**
+   * @param {Uint8Array} buf
+   */
+  writeBuf (buf) {
+    encoding.writeVarUint8Array(this.restEncoder, buf)
+  }
+
+  /**
+   * This is mainly here for legacy purposes.
+   *
+   * Initial we incoded objects using JSON. Now we use the much faster lib0/any-encoder. This method mainly exists for legacy purposes for the v1 encoder.
+   *
+   * @param {any} embed
+   */
+  writeJSON (embed) {
+    encoding.writeAny(this.restEncoder, embed)
+  }
+
+  /**
+   * Property keys are often reused. For example, in y-prosemirror the key `bold` might
+   * occur very often. For a 3d application, the key `position` might occur very often.
+   *
+   * We cache these keys in a Map and refer to them via a unique number.
+   *
+   * @param {string} key
+   */
+  writeKey (key) {
+    const clock = this.keyMap.get(key)
+    if (clock === undefined) {
+      this.keyClockEncoder.write(this.keyClock++)
+      this.stringEncoder.write(key)
+    } else {
+      this.keyClockEncoder.write(this.keyClock++)
+    }
+  }
+}

src/utils/YEvent.js

@@ -0,0 +1,301 @@
+
+import {
+  isDeleted,
+  getMovedCoords,
+  ContentMove, Item, AbstractType, Transaction, AbstractStruct // eslint-disable-line
+} from '../internals.js'
+
+import * as set from 'lib0/set'
+import * as array from 'lib0/array'
+
+/**
+ * YEvent describes the changes on a YType.
+ */
+export class YEvent {
+  /**
+   * @param {AbstractType<any>} target The changed type.
+   * @param {Transaction} transaction
+   */
+  constructor (target, transaction) {
+    /**
+     * The type on which this event was created on.
+     * @type {AbstractType<any>}
+     */
+    this.target = target
+    /**
+     * The current target on which the observe callback is called.
+     * @type {AbstractType<any>}
+     */
+    this.currentTarget = target
+    /**
+     * The transaction that triggered this event.
+     * @type {Transaction}
+     */
+    this.transaction = transaction
+    /**
+     * @type {Object|null}
+     */
+    this._changes = null
+    /**
+     * @type {null | Map<string, { action: 'add' | 'update' | 'delete', oldValue: any, newValue: any }>}
+     */
+    this._keys = null
+    /**
+     * @type {null | Array<{ insert?: string | Array<any> | object | AbstractType<any>, retain?: number, delete?: number, attributes?: Object<string, any> }>}
+     */
+    this._delta = null
+  }
+
+  /**
+   * Computes the path from `y` to the changed type.
+   *
+   * @todo v14 should standardize on path: Array<{parent, index}> because that is easier to work with.
+   *
+   * The following property holds:
+   * @example
+   *   let type = y
+   *   event.path.forEach(dir => {
+   *     type = type.get(dir)
+   *   })
+   *   type === event.target // => true
+   */
+  get path () {
+    // @ts-ignore _item is defined because target is integrated
+    return getPathTo(this.currentTarget, this.target)
+  }
+
+  /**
+   * Check if a struct is deleted by this event.
+   *
+   * In contrast to change.deleted, this method also returns true if the struct was added and then deleted.
+   *
+   * @param {AbstractStruct} struct
+   * @return {boolean}
+   */
+  deletes (struct) {
+    return isDeleted(this.transaction.deleteSet, struct.id)
+  }
+
+  /**
+   * @type {Map<string, { action: 'add' | 'update' | 'delete', oldValue: any, newValue: any }>}
+   */
+  get keys () {
+    if (this._keys === null) {
+      const keys = new Map()
+      const target = this.target
+      const changed = /** @type Set<string|null> */ (this.transaction.changed.get(target))
+      changed.forEach(key => {
+        if (key !== null) {
+          const item = /** @type {Item} */ (target._map.get(key))
+          /**
+           * @type {'delete' | 'add' | 'update'}
+           */
+          let action
+          let oldValue
+          if (this.adds(item)) {
+            let prev = item.left
+            while (prev !== null && this.adds(prev)) {
+              prev = prev.left
+            }
+            if (this.deletes(item)) {
+              if (prev !== null && this.deletes(prev)) {
+                action = 'delete'
+                oldValue = array.last(prev.content.getContent())
+              } else {
+                return
+              }
+            } else {
+              if (prev !== null && this.deletes(prev)) {
+                action = 'update'
+                oldValue = array.last(prev.content.getContent())
+              } else {
+                action = 'add'
+                oldValue = undefined
+              }
+            }
+          } else {
+            if (this.deletes(item)) {
+              action = 'delete'
+              oldValue = array.last(/** @type {Item} */ item.content.getContent())
+            } else {
+              return // nop
+            }
+          }
+          keys.set(key, { action, oldValue })
+        }
+      })
+      this._keys = keys
+    }
+    return this._keys
+  }
+
+  /**
+   * @type {Array<{insert?: string | Array<any> | object | AbstractType<any>, retain?: number, delete?: number, attributes?: Object<string, any>}>}
+   */
+  get delta () {
+    return this.changes.delta
+  }
+
+  /**
+   * Check if a struct is added by this event.
+   *
+   * In contrast to change.deleted, this method also returns true if the struct was added and then deleted.
+   *
+   * @param {AbstractStruct} struct
+   * @return {boolean}
+   */
+  adds (struct) {
+    return struct.id.clock >= (this.transaction.beforeState.get(struct.id.client) || 0)
+  }
+
+  /**
+   * @type {{added:Set<Item>,deleted:Set<Item>,keys:Map<string,{action:'add'|'update'|'delete',oldValue:any}>,delta:Array<{insert?:Array<any>|string, delete?:number, retain?:number}>}}
+   */
+  get changes () {
+    let changes = this._changes
+    if (changes === null) {
+      this.transaction.doc.transact(tr => {
+        const target = this.target
+        const added = set.create()
+        const deleted = set.create()
+        /**
+         * @type {Array<{insert:Array<any>}|{delete:number}|{retain:number}>}
+         */
+        const delta = []
+        changes = {
+          added,
+          deleted,
+          delta,
+          keys: this.keys
+        }
+        const changed = /** @type Set<string|null> */ (this.transaction.changed.get(target))
+        if (changed.has(null)) {
+          /**
+           * @type {Array<{ end: Item | null, move: Item | null, isNew : boolean }>}
+           */
+          const movedStack = []
+          /**
+           * @type {Item | null}
+           */
+          let currMove = null
+          /**
+           * @type {boolean}
+           */
+          let currMoveIsNew = false
+          /**
+           * @type {Item | null}
+           */
+          let currMoveEnd = null
+          /**
+           * @type {any}
+           */
+          let lastOp = null
+          const packOp = () => {
+            if (lastOp) {
+              delta.push(lastOp)
+            }
+          }
+          for (let item = target._start; ;) {
+            if (item === currMoveEnd && currMove) {
+              item = currMove
+              const { end, move, isNew } = movedStack.pop() || { end: null, move: null, isNew: false }
+              currMoveIsNew = isNew
+              currMoveEnd = end
+              currMove = move
+            } else if (item === null) {
+              break
+            } else if (item.content.constructor === ContentMove) {
+              if (item.moved === currMove) {
+                movedStack.push({ end: currMoveEnd, move: currMove, isNew: currMoveIsNew })
+                const { start, end } = getMovedCoords(item.content, tr)
+                currMove = item
+                currMoveEnd = end
+                currMoveIsNew = this.adds(item)
+                item = start
+                continue // do not move to item.right
+              }
+            } else if (item.moved !== currMove) {
+              if (!currMoveIsNew && item.countable && item.moved && !this.adds(item) && this.adds(item.moved) && (this.transaction.prevMoved.get(item) || null) === currMove) {
+                if (lastOp === null || lastOp.delete === undefined) {
+                  packOp()
+                  lastOp = { delete: 0 }
+                }
+                lastOp.delete += item.length
+              }
+            } else if (item.deleted) {
+              if (!currMoveIsNew && this.deletes(item) && !this.adds(item)) {
+                if (lastOp === null || lastOp.delete === undefined) {
+                  packOp()
+                  lastOp = { delete: 0 }
+                }
+                lastOp.delete += item.length
+                deleted.add(item)
+              }
+            } else {
+              if (currMoveIsNew || this.adds(item)) {
+                if (lastOp === null || lastOp.insert === undefined) {
+                  packOp()
+                  lastOp = { insert: [] }
+                }
+                lastOp.insert = lastOp.insert.concat(item.content.getContent())
+                added.add(item)
+              } else {
+                if (lastOp === null || lastOp.retain === undefined) {
+                  packOp()
+                  lastOp = { retain: 0 }
+                }
+                lastOp.retain += item.length
+              }
+            }
+            item = /** @type {Item} */ (item).right
+          }
+          if (lastOp !== null && lastOp.retain === undefined) {
+            packOp()
+          }
+        }
+        this._changes = changes
+      })
+    }
+    return /** @type {any} */ (changes)
+  }
+}
+
+/**
+ * Compute the path from this type to the specified target.
+ *
+ * @example
+ *   // `child` should be accessible via `type.get(path[0]).get(path[1])..`
+ *   const path = type.getPathTo(child)
+ *   // assuming `type instanceof YArray`
+ *   console.log(path) // might look like => [2, 'key1']
+ *   child === type.get(path[0]).get(path[1])
+ *
+ * @param {AbstractType<any>} parent
+ * @param {AbstractType<any>} child target
+ * @return {Array<string|number>} Path to the target
+ *
+ * @private
+ * @function
+ */
+const getPathTo = (parent, child) => {
+  const path = []
+  while (child._item !== null && child !== parent) {
+    if (child._item.parentSub !== null) {
+      // parent is map-ish
+      path.unshift(child._item.parentSub)
+    } else {
+      // parent is array-ish
+      let i = 0
+      let c = /** @type {AbstractType<any>} */ (child._item.parent)._start
+      while (c !== child._item && c !== null) {
+        if (!c.deleted) {
+          i++
+        }
+        c = c.right
+      }
+      path.unshift(i)
+    }
+    child = /** @type {AbstractType<any>} */ (child._item.parent)
+  }
+  return path
+}

src/utils/encoding.js

@@ -0,0 +1,645 @@
+
+/**
+ * @module encoding
+ */
+/*
+ * We use the first five bits in the info flag for determining the type of the struct.
+ *
+ * 0: GC
+ * 1: Item with Deleted content
+ * 2: Item with JSON content
+ * 3: Item with Binary content
+ * 4: Item with String content
+ * 5: Item with Embed content (for richtext content)
+ * 6: Item with Format content (a formatting marker for richtext content)
+ * 7: Item with Type
+ */
+
+import {
+  findIndexSS,
+  getState,
+  createID,
+  getStateVector,
+  readAndApplyDeleteSet,
+  writeDeleteSet,
+  createDeleteSetFromStructStore,
+  transact,
+  readItemContent,
+  UpdateDecoderV1,
+  UpdateDecoderV2,
+  UpdateEncoderV1,
+  UpdateEncoderV2,
+  DSEncoderV2,
+  DSDecoderV1,
+  DSEncoderV1,
+  mergeUpdates,
+  mergeUpdatesV2,
+  Skip,
+  diffUpdateV2,
+  convertUpdateFormatV2ToV1,
+  DSDecoderV2, Doc, Transaction, GC, Item, StructStore // eslint-disable-line
+} from '../internals.js'
+
+import * as encoding from 'lib0/encoding'
+import * as decoding from 'lib0/decoding'
+import * as binary from 'lib0/binary'
+import * as map from 'lib0/map'
+import * as math from 'lib0/math'
+
+/**
+ * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+ * @param {Array<GC|Item>} structs All structs by `client`
+ * @param {number} client
+ * @param {number} clock write structs starting with `ID(client,clock)`
+ *
+ * @function
+ */
+const writeStructs = (encoder, structs, client, clock) => {
+  // write first id
+  clock = math.max(clock, structs[0].id.clock) // make sure the first id exists
+  const startNewStructs = findIndexSS(structs, clock)
+  // write # encoded structs
+  encoding.writeVarUint(encoder.restEncoder, structs.length - startNewStructs)
+  encoder.writeClient(client)
+  encoding.writeVarUint(encoder.restEncoder, clock)
+  const firstStruct = structs[startNewStructs]
+  // write first struct with an offset
+  firstStruct.write(encoder, clock - firstStruct.id.clock)
+  for (let i = startNewStructs + 1; i < structs.length; i++) {
+    structs[i].write(encoder, 0)
+  }
+}
+
+/**
+ * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+ * @param {StructStore} store
+ * @param {Map<number,number>} _sm
+ *
+ * @private
+ * @function
+ */
+export const writeClientsStructs = (encoder, store, _sm) => {
+  // we filter all valid _sm entries into sm
+  const sm = new Map()
+  _sm.forEach((clock, client) => {
+    // only write if new structs are available
+    if (getState(store, client) > clock) {
+      sm.set(client, clock)
+    }
+  })
+  getStateVector(store).forEach((clock, client) => {
+    if (!_sm.has(client)) {
+      sm.set(client, 0)
+    }
+  })
+  // write # states that were updated
+  encoding.writeVarUint(encoder.restEncoder, sm.size)
+  // Write items with higher client ids first
+  // This heavily improves the conflict algorithm.
+  Array.from(sm.entries()).sort((a, b) => b[0] - a[0]).forEach(([client, clock]) => {
+    // @ts-ignore
+    writeStructs(encoder, store.clients.get(client), client, clock)
+  })
+}
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder The decoder object to read data from.
+ * @param {Doc} doc
+ * @return {Map<number, { i: number, refs: Array<Item | GC> }>}
+ *
+ * @private
+ * @function
+ */
+export const readClientsStructRefs = (decoder, doc) => {
+  /**
+   * @type {Map<number, { i: number, refs: Array<Item | GC> }>}
+   */
+  const clientRefs = map.create()
+  const numOfStateUpdates = decoding.readVarUint(decoder.restDecoder)
+  for (let i = 0; i < numOfStateUpdates; i++) {
+    const numberOfStructs = decoding.readVarUint(decoder.restDecoder)
+    /**
+     * @type {Array<GC|Item>}
+     */
+    const refs = new Array(numberOfStructs)
+    const client = decoder.readClient()
+    let clock = decoding.readVarUint(decoder.restDecoder)
+    // const start = performance.now()
+    clientRefs.set(client, { i: 0, refs })
+    for (let i = 0; i < numberOfStructs; i++) {
+      const info = decoder.readInfo()
+      switch (binary.BITS5 & info) {
+        case 0: { // GC
+          const len = decoder.readLen()
+          refs[i] = new GC(createID(client, clock), len)
+          clock += len
+          break
+        }
+        case 10: { // Skip Struct (nothing to apply)
+          // @todo we could reduce the amount of checks by adding Skip struct to clientRefs so we know that something is missing.
+          const len = decoding.readVarUint(decoder.restDecoder)
+          refs[i] = new Skip(createID(client, clock), len)
+          clock += len
+          break
+        }
+        default: { // Item with content
+          /**
+           * The optimized implementation doesn't use any variables because inlining variables is faster.
+           * Below a non-optimized version is shown that implements the basic algorithm with
+           * a few comments
+           */
+          const cantCopyParentInfo = (info & (binary.BIT7 | binary.BIT8)) === 0
+          // If parent = null and neither left nor right are defined, then we know that `parent` is child of `y`
+          // and we read the next string as parentYKey.
+          // It indicates how we store/retrieve parent from `y.share`
+          // @type {string|null}
+          const struct = new Item(
+            createID(client, clock),
+            null, // leftd
+            (info & binary.BIT8) === binary.BIT8 ? decoder.readLeftID() : null, // origin
+            null, // right
+            (info & binary.BIT7) === binary.BIT7 ? decoder.readRightID() : null, // right origin
+            cantCopyParentInfo ? (decoder.readParentInfo() ? doc.get(decoder.readString()) : decoder.readLeftID()) : null, // parent
+            cantCopyParentInfo && (info & binary.BIT6) === binary.BIT6 ? decoder.readString() : null, // parentSub
+            readItemContent(decoder, info) // item content
+          )
+          /* A non-optimized implementation of the above algorithm:
+
+          // The item that was originally to the left of this item.
+          const origin = (info & binary.BIT8) === binary.BIT8 ? decoder.readLeftID() : null
+          // The item that was originally to the right of this item.
+          const rightOrigin = (info & binary.BIT7) === binary.BIT7 ? decoder.readRightID() : null
+          const cantCopyParentInfo = (info & (binary.BIT7 | binary.BIT8)) === 0
+          const hasParentYKey = cantCopyParentInfo ? decoder.readParentInfo() : false
+          // If parent = null and neither left nor right are defined, then we know that `parent` is child of `y`
+          // and we read the next string as parentYKey.
+          // It indicates how we store/retrieve parent from `y.share`
+          // @type {string|null}
+          const parentYKey = cantCopyParentInfo && hasParentYKey ? decoder.readString() : null
+
+          const struct = new Item(
+            createID(client, clock),
+            null, // leftd
+            origin, // origin
+            null, // right
+            rightOrigin, // right origin
+            cantCopyParentInfo && !hasParentYKey ? decoder.readLeftID() : (parentYKey !== null ? doc.get(parentYKey) : null), // parent
+            cantCopyParentInfo && (info & binary.BIT6) === binary.BIT6 ? decoder.readString() : null, // parentSub
+            readItemContent(decoder, info) // item content
+          )
+          */
+          refs[i] = struct
+          clock += struct.length
+        }
+      }
+    }
+    // console.log('time to read: ', performance.now() - start) // @todo remove
+  }
+  return clientRefs
+}
+
+/**
+ * Resume computing structs generated by struct readers.
+ *
+ * While there is something to do, we integrate structs in this order
+ * 1. top element on stack, if stack is not empty
+ * 2. next element from current struct reader (if empty, use next struct reader)
+ *
+ * If struct causally depends on another struct (ref.missing), we put next reader of
+ * `ref.id.client` on top of stack.
+ *
+ * At some point we find a struct that has no causal dependencies,
+ * then we start emptying the stack.
+ *
+ * It is not possible to have circles: i.e. struct1 (from client1) depends on struct2 (from client2)
+ * depends on struct3 (from client1). Therefore the max stack size is eqaul to `structReaders.length`.
+ *
+ * This method is implemented in a way so that we can resume computation if this update
+ * causally depends on another update.
+ *
+ * @param {Transaction} transaction
+ * @param {StructStore} store
+ * @param {Map<number, { i: number, refs: (GC | Item)[] }>} clientsStructRefs
+ * @return { null | { update: Uint8Array, missing: Map<number,number> } }
+ *
+ * @private
+ * @function
+ */
+const integrateStructs = (transaction, store, clientsStructRefs) => {
+  /**
+   * @type {Array<Item | GC>}
+   */
+  const stack = []
+  // sort them so that we take the higher id first, in case of conflicts the lower id will probably not conflict with the id from the higher user.
+  let clientsStructRefsIds = Array.from(clientsStructRefs.keys()).sort((a, b) => a - b)
+  if (clientsStructRefsIds.length === 0) {
+    return null
+  }
+  const getNextStructTarget = () => {
+    if (clientsStructRefsIds.length === 0) {
+      return null
+    }
+    let nextStructsTarget = /** @type {{i:number,refs:Array<GC|Item>}} */ (clientsStructRefs.get(clientsStructRefsIds[clientsStructRefsIds.length - 1]))
+    while (nextStructsTarget.refs.length === nextStructsTarget.i) {
+      clientsStructRefsIds.pop()
+      if (clientsStructRefsIds.length > 0) {
+        nextStructsTarget = /** @type {{i:number,refs:Array<GC|Item>}} */ (clientsStructRefs.get(clientsStructRefsIds[clientsStructRefsIds.length - 1]))
+      } else {
+        return null
+      }
+    }
+    return nextStructsTarget
+  }
+  let curStructsTarget = getNextStructTarget()
+  if (curStructsTarget === null && stack.length === 0) {
+    return null
+  }
+
+  /**
+   * @type {StructStore}
+   */
+  const restStructs = new StructStore()
+  const missingSV = new Map()
+  /**
+   * @param {number} client
+   * @param {number} clock
+   */
+  const updateMissingSv = (client, clock) => {
+    const mclock = missingSV.get(client)
+    if (mclock == null || mclock > clock) {
+      missingSV.set(client, clock)
+    }
+  }
+  /**
+   * @type {GC|Item}
+   */
+  let stackHead = /** @type {any} */ (curStructsTarget).refs[/** @type {any} */ (curStructsTarget).i++]
+  // caching the state because it is used very often
+  const state = new Map()
+
+  const addStackToRestSS = () => {
+    for (const item of stack) {
+      const client = item.id.client
+      const unapplicableItems = clientsStructRefs.get(client)
+      if (unapplicableItems) {
+        // decrement because we weren't able to apply previous operation
+        unapplicableItems.i--
+        restStructs.clients.set(client, unapplicableItems.refs.slice(unapplicableItems.i))
+        clientsStructRefs.delete(client)
+        unapplicableItems.i = 0
+        unapplicableItems.refs = []
+      } else {
+        // item was the last item on clientsStructRefs and the field was already cleared. Add item to restStructs and continue
+        restStructs.clients.set(client, [item])
+      }
+      // remove client from clientsStructRefsIds to prevent users from applying the same update again
+      clientsStructRefsIds = clientsStructRefsIds.filter(c => c !== client)
+    }
+    stack.length = 0
+  }
+
+  // iterate over all struct readers until we are done
+  while (true) {
+    if (stackHead.constructor !== Skip) {
+      const localClock = map.setIfUndefined(state, stackHead.id.client, () => getState(store, stackHead.id.client))
+      const offset = localClock - stackHead.id.clock
+      if (offset < 0) {
+        // update from the same client is missing
+        stack.push(stackHead)
+        updateMissingSv(stackHead.id.client, stackHead.id.clock - 1)
+        // hid a dead wall, add all items from stack to restSS
+        addStackToRestSS()
+      } else {
+        const missing = stackHead.getMissing(transaction, store)
+        if (missing !== null) {
+          stack.push(stackHead)
+          // get the struct reader that has the missing struct
+          /**
+           * @type {{ refs: Array<GC|Item>, i: number }}
+           */
+          const structRefs = clientsStructRefs.get(/** @type {number} */ (missing)) || { refs: [], i: 0 }
+          if (structRefs.refs.length === structRefs.i) {
+            // This update message causally depends on another update message that doesn't exist yet
+            updateMissingSv(/** @type {number} */ (missing), getState(store, missing))
+            addStackToRestSS()
+          } else {
+            stackHead = structRefs.refs[structRefs.i++]
+            continue
+          }
+        } else if (offset === 0 || offset < stackHead.length) {
+          // all fine, apply the stackhead
+          stackHead.integrate(transaction, offset)
+          state.set(stackHead.id.client, stackHead.id.clock + stackHead.length)
+        }
+      }
+    }
+    // iterate to next stackHead
+    if (stack.length > 0) {
+      stackHead = /** @type {GC|Item} */ (stack.pop())
+    } else if (curStructsTarget !== null && curStructsTarget.i < curStructsTarget.refs.length) {
+      stackHead = /** @type {GC|Item} */ (curStructsTarget.refs[curStructsTarget.i++])
+    } else {
+      curStructsTarget = getNextStructTarget()
+      if (curStructsTarget === null) {
+        // we are done!
+        break
+      } else {
+        stackHead = /** @type {GC|Item} */ (curStructsTarget.refs[curStructsTarget.i++])
+      }
+    }
+  }
+  if (restStructs.clients.size > 0) {
+    const encoder = new UpdateEncoderV2()
+    writeClientsStructs(encoder, restStructs, new Map())
+    // write empty deleteset
+    // writeDeleteSet(encoder, new DeleteSet())
+    encoding.writeVarUint(encoder.restEncoder, 0) // => no need for an extra function call, just write 0 deletes
+    return { missing: missingSV, update: encoder.toUint8Array() }
+  }
+  return null
+}
+
+/**
+ * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+ * @param {Transaction} transaction
+ *
+ * @private
+ * @function
+ */
+export const writeStructsFromTransaction = (encoder, transaction) => writeClientsStructs(encoder, transaction.doc.store, transaction.beforeState)
+
+/**
+ * Read and apply a document update.
+ *
+ * This function has the same effect as `applyUpdate` but accepts an decoder.
+ *
+ * @param {decoding.Decoder} decoder
+ * @param {Doc} ydoc
+ * @param {any} [transactionOrigin] This will be stored on `transaction.origin` and `.on('update', (update, origin))`
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} [structDecoder]
+ *
+ * @function
+ */
+export const readUpdateV2 = (decoder, ydoc, transactionOrigin, structDecoder = new UpdateDecoderV2(decoder)) =>
+  transact(ydoc, transaction => {
+    // force that transaction.local is set to non-local
+    transaction.local = false
+    let retry = false
+    const doc = transaction.doc
+    const store = doc.store
+    // let start = performance.now()
+    const ss = readClientsStructRefs(structDecoder, doc)
+    // console.log('time to read structs: ', performance.now() - start) // @todo remove
+    // start = performance.now()
+    // console.log('time to merge: ', performance.now() - start) // @todo remove
+    // start = performance.now()
+    const restStructs = integrateStructs(transaction, store, ss)
+    const pending = store.pendingStructs
+    if (pending) {
+      // check if we can apply something
+      for (const [client, clock] of pending.missing) {
+        if (clock < getState(store, client)) {
+          retry = true
+          break
+        }
+      }
+      if (restStructs) {
+        // merge restStructs into store.pending
+        for (const [client, clock] of restStructs.missing) {
+          const mclock = pending.missing.get(client)
+          if (mclock == null || mclock > clock) {
+            pending.missing.set(client, clock)
+          }
+        }
+        pending.update = mergeUpdatesV2([pending.update, restStructs.update])
+      }
+    } else {
+      store.pendingStructs = restStructs
+    }
+    // console.log('time to integrate: ', performance.now() - start) // @todo remove
+    // start = performance.now()
+    const dsRest = readAndApplyDeleteSet(structDecoder, transaction, store)
+    if (store.pendingDs) {
+      // @todo we could make a lower-bound state-vector check as we do above
+      const pendingDSUpdate = new UpdateDecoderV2(decoding.createDecoder(store.pendingDs))
+      decoding.readVarUint(pendingDSUpdate.restDecoder) // read 0 structs, because we only encode deletes in pendingdsupdate
+      const dsRest2 = readAndApplyDeleteSet(pendingDSUpdate, transaction, store)
+      if (dsRest && dsRest2) {
+        // case 1: ds1 != null && ds2 != null
+        store.pendingDs = mergeUpdatesV2([dsRest, dsRest2])
+      } else {
+        // case 2: ds1 != null
+        // case 3: ds2 != null
+        // case 4: ds1 == null && ds2 == null
+        store.pendingDs = dsRest || dsRest2
+      }
+    } else {
+      // Either dsRest == null && pendingDs == null OR dsRest != null
+      store.pendingDs = dsRest
+    }
+    // console.log('time to cleanup: ', performance.now() - start) // @todo remove
+    // start = performance.now()
+
+    // console.log('time to resume delete readers: ', performance.now() - start) // @todo remove
+    // start = performance.now()
+    if (retry) {
+      const update = /** @type {{update: Uint8Array}} */ (store.pendingStructs).update
+      store.pendingStructs = null
+      applyUpdateV2(transaction.doc, update)
+    }
+  }, transactionOrigin, false)
+
+/**
+ * Read and apply a document update.
+ *
+ * This function has the same effect as `applyUpdate` but accepts an decoder.
+ *
+ * @param {decoding.Decoder} decoder
+ * @param {Doc} ydoc
+ * @param {any} [transactionOrigin] This will be stored on `transaction.origin` and `.on('update', (update, origin))`
+ *
+ * @function
+ */
+export const readUpdate = (decoder, ydoc, transactionOrigin) => readUpdateV2(decoder, ydoc, transactionOrigin, new UpdateDecoderV1(decoder))
+
+/**
+ * Apply a document update created by, for example, `y.on('update', update => ..)` or `update = encodeStateAsUpdate()`.
+ *
+ * This function has the same effect as `readUpdate` but accepts an Uint8Array instead of a Decoder.
+ *
+ * @param {Doc} ydoc
+ * @param {Uint8Array} update
+ * @param {any} [transactionOrigin] This will be stored on `transaction.origin` and `.on('update', (update, origin))`
+ * @param {typeof UpdateDecoderV1 | typeof UpdateDecoderV2} [YDecoder]
+ *
+ * @function
+ */
+export const applyUpdateV2 = (ydoc, update, transactionOrigin, YDecoder = UpdateDecoderV2) => {
+  const decoder = decoding.createDecoder(update)
+  readUpdateV2(decoder, ydoc, transactionOrigin, new YDecoder(decoder))
+}
+
+/**
+ * Apply a document update created by, for example, `y.on('update', update => ..)` or `update = encodeStateAsUpdate()`.
+ *
+ * This function has the same effect as `readUpdate` but accepts an Uint8Array instead of a Decoder.
+ *
+ * @param {Doc} ydoc
+ * @param {Uint8Array} update
+ * @param {any} [transactionOrigin] This will be stored on `transaction.origin` and `.on('update', (update, origin))`
+ *
+ * @function
+ */
+export const applyUpdate = (ydoc, update, transactionOrigin) => applyUpdateV2(ydoc, update, transactionOrigin, UpdateDecoderV1)
+
+/**
+ * Write all the document as a single update message. If you specify the state of the remote client (`targetStateVector`) it will
+ * only write the operations that are missing.
+ *
+ * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+ * @param {Doc} doc
+ * @param {Map<number,number>} [targetStateVector] The state of the target that receives the update. Leave empty to write all known structs
+ *
+ * @function
+ */
+export const writeStateAsUpdate = (encoder, doc, targetStateVector = new Map()) => {
+  writeClientsStructs(encoder, doc.store, targetStateVector)
+  writeDeleteSet(encoder, createDeleteSetFromStructStore(doc.store))
+}
+
+/**
+ * Write all the document as a single update message that can be applied on the remote document. If you specify the state of the remote client (`targetState`) it will
+ * only write the operations that are missing.
+ *
+ * Use `writeStateAsUpdate` instead if you are working with lib0/encoding.js#Encoder
+ *
+ * @param {Doc} doc
+ * @param {Uint8Array} [encodedTargetStateVector] The state of the target that receives the update. Leave empty to write all known structs
+ * @param {UpdateEncoderV1 | UpdateEncoderV2} [encoder]
+ * @return {Uint8Array}
+ *
+ * @function
+ */
+export const encodeStateAsUpdateV2 = (doc, encodedTargetStateVector = new Uint8Array([0]), encoder = new UpdateEncoderV2()) => {
+  const targetStateVector = decodeStateVector(encodedTargetStateVector)
+  writeStateAsUpdate(encoder, doc, targetStateVector)
+  const updates = [encoder.toUint8Array()]
+  // also add the pending updates (if there are any)
+  if (doc.store.pendingDs) {
+    updates.push(doc.store.pendingDs)
+  }
+  if (doc.store.pendingStructs) {
+    updates.push(diffUpdateV2(doc.store.pendingStructs.update, encodedTargetStateVector))
+  }
+  if (updates.length > 1) {
+    if (encoder.constructor === UpdateEncoderV1) {
+      return mergeUpdates(updates.map((update, i) => i === 0 ? update : convertUpdateFormatV2ToV1(update)))
+    } else if (encoder.constructor === UpdateEncoderV2) {
+      return mergeUpdatesV2(updates)
+    }
+  }
+  return updates[0]
+}
+
+/**
+ * Write all the document as a single update message that can be applied on the remote document. If you specify the state of the remote client (`targetState`) it will
+ * only write the operations that are missing.
+ *
+ * Use `writeStateAsUpdate` instead if you are working with lib0/encoding.js#Encoder
+ *
+ * @param {Doc} doc
+ * @param {Uint8Array} [encodedTargetStateVector] The state of the target that receives the update. Leave empty to write all known structs
+ * @return {Uint8Array}
+ *
+ * @function
+ */
+export const encodeStateAsUpdate = (doc, encodedTargetStateVector) => encodeStateAsUpdateV2(doc, encodedTargetStateVector, new UpdateEncoderV1())
+
+/**
+ * Read state vector from Decoder and return as Map
+ *
+ * @param {DSDecoderV1 | DSDecoderV2} decoder
+ * @return {Map<number,number>} Maps `client` to the number next expected `clock` from that client.
+ *
+ * @function
+ */
+export const readStateVector = decoder => {
+  const ss = new Map()
+  const ssLength = decoding.readVarUint(decoder.restDecoder)
+  for (let i = 0; i < ssLength; i++) {
+    const client = decoding.readVarUint(decoder.restDecoder)
+    const clock = decoding.readVarUint(decoder.restDecoder)
+    ss.set(client, clock)
+  }
+  return ss
+}
+
+/**
+ * Read decodedState and return State as Map.
+ *
+ * @param {Uint8Array} decodedState
+ * @return {Map<number,number>} Maps `client` to the number next expected `clock` from that client.
+ *
+ * @function
+ */
+// export const decodeStateVectorV2 = decodedState => readStateVector(new DSDecoderV2(decoding.createDecoder(decodedState)))
+
+/**
+ * Read decodedState and return State as Map.
+ *
+ * @param {Uint8Array} decodedState
+ * @return {Map<number,number>} Maps `client` to the number next expected `clock` from that client.
+ *
+ * @function
+ */
+export const decodeStateVector = decodedState => readStateVector(new DSDecoderV1(decoding.createDecoder(decodedState)))
+
+/**
+ * @param {DSEncoderV1 | DSEncoderV2} encoder
+ * @param {Map<number,number>} sv
+ * @function
+ */
+export const writeStateVector = (encoder, sv) => {
+  encoding.writeVarUint(encoder.restEncoder, sv.size)
+  Array.from(sv.entries()).sort((a, b) => b[0] - a[0]).forEach(([client, clock]) => {
+    encoding.writeVarUint(encoder.restEncoder, client) // @todo use a special client decoder that is based on mapping
+    encoding.writeVarUint(encoder.restEncoder, clock)
+  })
+  return encoder
+}
+
+/**
+ * @param {DSEncoderV1 | DSEncoderV2} encoder
+ * @param {Doc} doc
+ *
+ * @function
+ */
+export const writeDocumentStateVector = (encoder, doc) => writeStateVector(encoder, getStateVector(doc.store))
+
+/**
+ * Encode State as Uint8Array.
+ *
+ * @param {Doc|Map<number,number>} doc
+ * @param {DSEncoderV1 | DSEncoderV2} [encoder]
+ * @return {Uint8Array}
+ *
+ * @function
+ */
+export const encodeStateVectorV2 = (doc, encoder = new DSEncoderV2()) => {
+  if (doc instanceof Map) {
+    writeStateVector(encoder, doc)
+  } else {
+    writeDocumentStateVector(encoder, doc)
+  }
+  return encoder.toUint8Array()
+}
+
+/**
+ * Encode State as Uint8Array.
+ *
+ * @param {Doc|Map<number,number>} doc
+ * @return {Uint8Array}
+ *
+ * @function
+ */
+export const encodeStateVector = doc => encodeStateVectorV2(doc, new DSEncoderV1())

src/utils/isParentOf.js

@@ -0,0 +1,22 @@
+
+import { AbstractType, Item } from '../internals.js' // eslint-disable-line
+
+/**
+ * Check if `parent` is a parent of `child`.
+ *
+ * @param {AbstractType<any>} parent
+ * @param {Item|null} child
+ * @return {Boolean} Whether `parent` is a parent of `child`.
+ *
+ * @private
+ * @function
+ */
+export const isParentOf = (parent, child) => {
+  while (child !== null) {
+    if (child.parent === parent) {
+      return true
+    }
+    child = /** @type {AbstractType<any>} */ (child.parent)._item
+  }
+  return false
+}

src/utils/logging.js

@@ -0,0 +1,22 @@
+
+import {
+  AbstractType // eslint-disable-line
+} from '../internals.js'
+
+/**
+ * Convenient helper to log type information.
+ *
+ * Do not use in productive systems as the output can be immense!
+ *
+ * @param {AbstractType<any>} type
+ */
+export const logType = type => {
+  const res = []
+  let n = type._start
+  while (n) {
+    res.push(n)
+    n = n.right
+  }
+  console.log('Children: ', res)
+  console.log('Children content: ', res.filter(m => !m.deleted).map(m => m.content))
+}

src/utils/updates.js

@@ -0,0 +1,558 @@
+
+import * as binary from 'lib0/binary'
+import * as decoding from 'lib0/decoding'
+import * as encoding from 'lib0/encoding'
+import * as logging from 'lib0/logging'
+import * as math from 'lib0/math'
+import {
+  createID,
+  readItemContent,
+  readDeleteSet,
+  writeDeleteSet,
+  Skip,
+  mergeDeleteSets,
+  DSEncoderV1,
+  DSEncoderV2,
+  decodeStateVector,
+  Item, GC, UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2 // eslint-disable-line
+} from '../internals.js'
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ */
+function * lazyStructReaderGenerator (decoder) {
+  const numOfStateUpdates = decoding.readVarUint(decoder.restDecoder)
+  for (let i = 0; i < numOfStateUpdates; i++) {
+    const numberOfStructs = decoding.readVarUint(decoder.restDecoder)
+    const client = decoder.readClient()
+    let clock = decoding.readVarUint(decoder.restDecoder)
+    for (let i = 0; i < numberOfStructs; i++) {
+      const info = decoder.readInfo()
+      // @todo use switch instead of ifs
+      if (info === 10) {
+        const len = decoding.readVarUint(decoder.restDecoder)
+        yield new Skip(createID(client, clock), len)
+        clock += len
+      } else if ((binary.BITS5 & info) !== 0) {
+        const cantCopyParentInfo = (info & (binary.BIT7 | binary.BIT8)) === 0
+        // If parent = null and neither left nor right are defined, then we know that `parent` is child of `y`
+        // and we read the next string as parentYKey.
+        // It indicates how we store/retrieve parent from `y.share`
+        // @type {string|null}
+        const struct = new Item(
+          createID(client, clock),
+          null, // left
+          (info & binary.BIT8) === binary.BIT8 ? decoder.readLeftID() : null, // origin
+          null, // right
+          (info & binary.BIT7) === binary.BIT7 ? decoder.readRightID() : null, // right origin
+          // @ts-ignore Force writing a string here.
+          cantCopyParentInfo ? (decoder.readParentInfo() ? decoder.readString() : decoder.readLeftID()) : null, // parent
+          cantCopyParentInfo && (info & binary.BIT6) === binary.BIT6 ? decoder.readString() : null, // parentSub
+          readItemContent(decoder, info) // item content
+        )
+        yield struct
+        clock += struct.length
+      } else {
+        const len = decoder.readLen()
+        yield new GC(createID(client, clock), len)
+        clock += len
+      }
+    }
+  }
+}
+
+export class LazyStructReader {
+  /**
+   * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+   * @param {boolean} filterSkips
+   */
+  constructor (decoder, filterSkips) {
+    this.gen = lazyStructReaderGenerator(decoder)
+    /**
+     * @type {null | Item | Skip | GC}
+     */
+    this.curr = null
+    this.done = false
+    this.filterSkips = filterSkips
+    this.next()
+  }
+
+  /**
+   * @return {Item | GC | Skip |null}
+   */
+  next () {
+    // ignore "Skip" structs
+    do {
+      this.curr = this.gen.next().value || null
+    } while (this.filterSkips && this.curr !== null && this.curr.constructor === Skip)
+    return this.curr
+  }
+}
+
+/**
+ * @param {Uint8Array} update
+ *
+ */
+export const logUpdate = update => logUpdateV2(update, UpdateDecoderV1)
+
+/**
+ * @param {Uint8Array} update
+ * @param {typeof UpdateDecoderV2 | typeof UpdateDecoderV1} [YDecoder]
+ *
+ */
+export const logUpdateV2 = (update, YDecoder = UpdateDecoderV2) => {
+  const structs = []
+  const updateDecoder = new YDecoder(decoding.createDecoder(update))
+  const lazyDecoder = new LazyStructReader(updateDecoder, false)
+  for (let curr = lazyDecoder.curr; curr !== null; curr = lazyDecoder.next()) {
+    structs.push(curr)
+  }
+  logging.print('Structs: ', structs)
+  const ds = readDeleteSet(updateDecoder)
+  logging.print('DeleteSet: ', ds)
+}
+
+export class LazyStructWriter {
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   */
+  constructor (encoder) {
+    this.currClient = 0
+    this.startClock = 0
+    this.written = 0
+    this.encoder = encoder
+    /**
+     * We want to write operations lazily, but also we need to know beforehand how many operations we want to write for each client.
+     *
+     * This kind of meta-information (#clients, #structs-per-client-written) is written to the restEncoder.
+     *
+     * We fragment the restEncoder and store a slice of it per-client until we know how many clients there are.
+     * When we flush (toUint8Array) we write the restEncoder using the fragments and the meta-information.
+     *
+     * @type {Array<{ written: number, restEncoder: Uint8Array }>}
+     */
+    this.clientStructs = []
+  }
+}
+
+/**
+ * @param {Array<Uint8Array>} updates
+ * @return {Uint8Array}
+ */
+export const mergeUpdates = updates => mergeUpdatesV2(updates, UpdateDecoderV1, UpdateEncoderV1)
+
+/**
+ * @param {Uint8Array} update
+ * @param {typeof DSEncoderV1 | typeof DSEncoderV2} YEncoder
+ * @param {typeof UpdateDecoderV1 | typeof UpdateDecoderV2} YDecoder
+ * @return {Uint8Array}
+ */
+export const encodeStateVectorFromUpdateV2 = (update, YEncoder = DSEncoderV2, YDecoder = UpdateDecoderV2) => {
+  const encoder = new YEncoder()
+  const updateDecoder = new LazyStructReader(new YDecoder(decoding.createDecoder(update)), false)
+  let curr = updateDecoder.curr
+  if (curr !== null) {
+    let size = 0
+    let currClient = curr.id.client
+    let stopCounting = curr.id.clock !== 0 // must start at 0
+    let currClock = stopCounting ? 0 : curr.id.clock + curr.length
+    for (; curr !== null; curr = updateDecoder.next()) {
+      if (currClient !== curr.id.client) {
+        if (currClock !== 0) {
+          size++
+          // We found a new client
+          // write what we have to the encoder
+          encoding.writeVarUint(encoder.restEncoder, currClient)
+          encoding.writeVarUint(encoder.restEncoder, currClock)
+        }
+        currClient = curr.id.client
+        currClock = 0
+        stopCounting = curr.id.clock !== 0
+      }
+      // we ignore skips
+      if (curr.constructor === Skip) {
+        stopCounting = true
+      }
+      if (!stopCounting) {
+        currClock = curr.id.clock + curr.length
+      }
+    }
+    // write what we have
+    if (currClock !== 0) {
+      size++
+      encoding.writeVarUint(encoder.restEncoder, currClient)
+      encoding.writeVarUint(encoder.restEncoder, currClock)
+    }
+    // prepend the size of the state vector
+    const enc = encoding.createEncoder()
+    encoding.writeVarUint(enc, size)
+    encoding.writeBinaryEncoder(enc, encoder.restEncoder)
+    encoder.restEncoder = enc
+    return encoder.toUint8Array()
+  } else {
+    encoding.writeVarUint(encoder.restEncoder, 0)
+    return encoder.toUint8Array()
+  }
+}
+
+/**
+ * @param {Uint8Array} update
+ * @return {Uint8Array}
+ */
+export const encodeStateVectorFromUpdate = update => encodeStateVectorFromUpdateV2(update, DSEncoderV1, UpdateDecoderV1)
+
+/**
+ * @param {Uint8Array} update
+ * @param {typeof UpdateDecoderV1 | typeof UpdateDecoderV2} YDecoder
+ * @return {{ from: Map<number,number>, to: Map<number,number> }}
+ */
+export const parseUpdateMetaV2 = (update, YDecoder = UpdateDecoderV2) => {
+  /**
+   * @type {Map<number, number>}
+   */
+  const from = new Map()
+  /**
+   * @type {Map<number, number>}
+   */
+  const to = new Map()
+  const updateDecoder = new LazyStructReader(new YDecoder(decoding.createDecoder(update)), false)
+  let curr = updateDecoder.curr
+  if (curr !== null) {
+    let currClient = curr.id.client
+    let currClock = curr.id.clock
+    // write the beginning to `from`
+    from.set(currClient, currClock)
+    for (; curr !== null; curr = updateDecoder.next()) {
+      if (currClient !== curr.id.client) {
+        // We found a new client
+        // write the end to `to`
+        to.set(currClient, currClock)
+        // write the beginning to `from`
+        from.set(curr.id.client, curr.id.clock)
+        // update currClient
+        currClient = curr.id.client
+      }
+      currClock = curr.id.clock + curr.length
+    }
+    // write the end to `to`
+    to.set(currClient, currClock)
+  }
+  return { from, to }
+}
+
+/**
+ * @param {Uint8Array} update
+ * @return {{ from: Map<number,number>, to: Map<number,number> }}
+ */
+export const parseUpdateMeta = update => parseUpdateMetaV2(update, UpdateDecoderV1)
+
+/**
+ * This method is intended to slice any kind of struct and retrieve the right part.
+ * It does not handle side-effects, so it should only be used by the lazy-encoder.
+ *
+ * @param {Item | GC | Skip} left
+ * @param {number} diff
+ * @return {Item | GC}
+ */
+const sliceStruct = (left, diff) => {
+  if (left.constructor === GC) {
+    const { client, clock } = left.id
+    return new GC(createID(client, clock + diff), left.length - diff)
+  } else if (left.constructor === Skip) {
+    const { client, clock } = left.id
+    return new Skip(createID(client, clock + diff), left.length - diff)
+  } else {
+    const leftItem = /** @type {Item} */ (left)
+    const { client, clock } = leftItem.id
+    return new Item(
+      createID(client, clock + diff),
+      null,
+      createID(client, clock + diff - 1),
+      null,
+      leftItem.rightOrigin,
+      leftItem.parent,
+      leftItem.parentSub,
+      leftItem.content.splice(diff)
+    )
+  }
+}
+
+/**
+ *
+ * This function works similarly to `readUpdateV2`.
+ *
+ * @param {Array<Uint8Array>} updates
+ * @param {typeof UpdateDecoderV1 | typeof UpdateDecoderV2} [YDecoder]
+ * @param {typeof UpdateEncoderV1 | typeof UpdateEncoderV2} [YEncoder]
+ * @return {Uint8Array}
+ */
+export const mergeUpdatesV2 = (updates, YDecoder = UpdateDecoderV2, YEncoder = UpdateEncoderV2) => {
+  if (updates.length === 1) {
+    return updates[0]
+  }
+  const updateDecoders = updates.map(update => new YDecoder(decoding.createDecoder(update)))
+  let lazyStructDecoders = updateDecoders.map(decoder => new LazyStructReader(decoder, true))
+
+  /**
+   * @todo we don't need offset because we always slice before
+   * @type {null | { struct: Item | GC | Skip, offset: number }}
+   */
+  let currWrite = null
+
+  const updateEncoder = new YEncoder()
+  // write structs lazily
+  const lazyStructEncoder = new LazyStructWriter(updateEncoder)
+
+  // Note: We need to ensure that all lazyStructDecoders are fully consumed
+  // Note: Should merge document updates whenever possible - even from different updates
+  // Note: Should handle that some operations cannot be applied yet ()
+
+  while (true) {
+    // @todo this incurs an exponential overhead. We could instead only sort the item that changed.
+    // Write higher clients first ⇒ sort by clientID & clock and remove decoders without content
+    lazyStructDecoders = lazyStructDecoders.filter(dec => dec.curr !== null)
+    lazyStructDecoders.sort(
+      /** @type {function(any,any):number} */ (dec1, dec2) => {
+        if (dec1.curr.id.client === dec2.curr.id.client) {
+          const clockDiff = dec1.curr.id.clock - dec2.curr.id.clock
+          if (clockDiff === 0) {
+            // @todo remove references to skip since the structDecoders must filter Skips.
+            return dec1.curr.constructor === dec2.curr.constructor
+              ? 0
+              : dec1.curr.constructor === Skip ? 1 : -1 // we are filtering skips anyway.
+          } else {
+            return clockDiff
+          }
+        } else {
+          return dec2.curr.id.client - dec1.curr.id.client
+        }
+      }
+    )
+    if (lazyStructDecoders.length === 0) {
+      break
+    }
+    const currDecoder = lazyStructDecoders[0]
+    // write from currDecoder until the next operation is from another client or if filler-struct
+    // then we need to reorder the decoders and find the next operation to write
+    const firstClient = /** @type {Item | GC} */ (currDecoder.curr).id.client
+
+    if (currWrite !== null) {
+      let curr = /** @type {Item | GC | null} */ (currDecoder.curr)
+      let iterated = false
+
+      // iterate until we find something that we haven't written already
+      // remember: first the high client-ids are written
+      while (curr !== null && curr.id.clock + curr.length <= currWrite.struct.id.clock + currWrite.struct.length && curr.id.client >= currWrite.struct.id.client) {
+        curr = currDecoder.next()
+        iterated = true
+      }
+      if (
+        curr === null || // current decoder is empty
+        curr.id.client !== firstClient || // check whether there is another decoder that has has updates from `firstClient`
+        (iterated && curr.id.clock > currWrite.struct.id.clock + currWrite.struct.length) // the above while loop was used and we are potentially missing updates
+      ) {
+        continue
+      }
+
+      if (firstClient !== currWrite.struct.id.client) {
+        writeStructToLazyStructWriter(lazyStructEncoder, currWrite.struct, currWrite.offset)
+        currWrite = { struct: curr, offset: 0 }
+        currDecoder.next()
+      } else {
+        if (currWrite.struct.id.clock + currWrite.struct.length < curr.id.clock) {
+          // @todo write currStruct & set currStruct = Skip(clock = currStruct.id.clock + currStruct.length, length = curr.id.clock - self.clock)
+          if (currWrite.struct.constructor === Skip) {
+            // extend existing skip
+            currWrite.struct.length = curr.id.clock + curr.length - currWrite.struct.id.clock
+          } else {
+            writeStructToLazyStructWriter(lazyStructEncoder, currWrite.struct, currWrite.offset)
+            const diff = curr.id.clock - currWrite.struct.id.clock - currWrite.struct.length
+            /**
+             * @type {Skip}
+             */
+            const struct = new Skip(createID(firstClient, currWrite.struct.id.clock + currWrite.struct.length), diff)
+            currWrite = { struct, offset: 0 }
+          }
+        } else { // if (currWrite.struct.id.clock + currWrite.struct.length >= curr.id.clock) {
+          const diff = currWrite.struct.id.clock + currWrite.struct.length - curr.id.clock
+          if (diff > 0) {
+            if (currWrite.struct.constructor === Skip) {
+              // prefer to slice Skip because the other struct might contain more information
+              currWrite.struct.length -= diff
+            } else {
+              curr = sliceStruct(curr, diff)
+            }
+          }
+          if (!currWrite.struct.mergeWith(/** @type {any} */ (curr))) {
+            writeStructToLazyStructWriter(lazyStructEncoder, currWrite.struct, currWrite.offset)
+            currWrite = { struct: curr, offset: 0 }
+            currDecoder.next()
+          }
+        }
+      }
+    } else {
+      currWrite = { struct: /** @type {Item | GC} */ (currDecoder.curr), offset: 0 }
+      currDecoder.next()
+    }
+    for (
+      let next = currDecoder.curr;
+      next !== null && next.id.client === firstClient && next.id.clock === currWrite.struct.id.clock + currWrite.struct.length && next.constructor !== Skip;
+      next = currDecoder.next()
+    ) {
+      writeStructToLazyStructWriter(lazyStructEncoder, currWrite.struct, currWrite.offset)
+      currWrite = { struct: next, offset: 0 }
+    }
+  }
+  if (currWrite !== null) {
+    writeStructToLazyStructWriter(lazyStructEncoder, currWrite.struct, currWrite.offset)
+    currWrite = null
+  }
+  finishLazyStructWriting(lazyStructEncoder)
+
+  const dss = updateDecoders.map(decoder => readDeleteSet(decoder))
+  const ds = mergeDeleteSets(dss)
+  writeDeleteSet(updateEncoder, ds)
+  return updateEncoder.toUint8Array()
+}
+
+/**
+ * @param {Uint8Array} update
+ * @param {Uint8Array} sv
+ * @param {typeof UpdateDecoderV1 | typeof UpdateDecoderV2} [YDecoder]
+ * @param {typeof UpdateEncoderV1 | typeof UpdateEncoderV2} [YEncoder]
+ */
+export const diffUpdateV2 = (update, sv, YDecoder = UpdateDecoderV2, YEncoder = UpdateEncoderV2) => {
+  const state = decodeStateVector(sv)
+  const encoder = new YEncoder()
+  const lazyStructWriter = new LazyStructWriter(encoder)
+  const decoder = new YDecoder(decoding.createDecoder(update))
+  const reader = new LazyStructReader(decoder, false)
+  while (reader.curr) {
+    const curr = reader.curr
+    const currClient = curr.id.client
+    const svClock = state.get(currClient) || 0
+    if (reader.curr.constructor === Skip) {
+      // the first written struct shouldn't be a skip
+      reader.next()
+      continue
+    }
+    if (curr.id.clock + curr.length > svClock) {
+      writeStructToLazyStructWriter(lazyStructWriter, curr, math.max(svClock - curr.id.clock, 0))
+      reader.next()
+      while (reader.curr && reader.curr.id.client === currClient) {
+        writeStructToLazyStructWriter(lazyStructWriter, reader.curr, 0)
+        reader.next()
+      }
+    } else {
+      // read until something new comes up
+      while (reader.curr && reader.curr.id.client === currClient && reader.curr.id.clock + reader.curr.length <= svClock) {
+        reader.next()
+      }
+    }
+  }
+  finishLazyStructWriting(lazyStructWriter)
+  // write ds
+  const ds = readDeleteSet(decoder)
+  writeDeleteSet(encoder, ds)
+  return encoder.toUint8Array()
+}
+
+/**
+ * @param {Uint8Array} update
+ * @param {Uint8Array} sv
+ */
+export const diffUpdate = (update, sv) => diffUpdateV2(update, sv, UpdateDecoderV1, UpdateEncoderV1)
+
+/**
+ * @param {LazyStructWriter} lazyWriter
+ */
+const flushLazyStructWriter = lazyWriter => {
+  if (lazyWriter.written > 0) {
+    lazyWriter.clientStructs.push({ written: lazyWriter.written, restEncoder: encoding.toUint8Array(lazyWriter.encoder.restEncoder) })
+    lazyWriter.encoder.restEncoder = encoding.createEncoder()
+    lazyWriter.written = 0
+  }
+}
+
+/**
+ * @param {LazyStructWriter} lazyWriter
+ * @param {Item | GC} struct
+ * @param {number} offset
+ */
+const writeStructToLazyStructWriter = (lazyWriter, struct, offset) => {
+  // flush curr if we start another client
+  if (lazyWriter.written > 0 && lazyWriter.currClient !== struct.id.client) {
+    flushLazyStructWriter(lazyWriter)
+  }
+  if (lazyWriter.written === 0) {
+    lazyWriter.currClient = struct.id.client
+    // write next client
+    lazyWriter.encoder.writeClient(struct.id.client)
+    // write startClock
+    encoding.writeVarUint(lazyWriter.encoder.restEncoder, struct.id.clock + offset)
+  }
+  struct.write(lazyWriter.encoder, offset)
+  lazyWriter.written++
+}
+/**
+ * Call this function when we collected all parts and want to
+ * put all the parts together. After calling this method,
+ * you can continue using the UpdateEncoder.
+ *
+ * @param {LazyStructWriter} lazyWriter
+ */
+const finishLazyStructWriting = (lazyWriter) => {
+  flushLazyStructWriter(lazyWriter)
+
+  // this is a fresh encoder because we called flushCurr
+  const restEncoder = lazyWriter.encoder.restEncoder
+
+  /**
+   * Now we put all the fragments together.
+   * This works similarly to `writeClientsStructs`
+   */
+
+  // write # states that were updated - i.e. the clients
+  encoding.writeVarUint(restEncoder, lazyWriter.clientStructs.length)
+
+  for (let i = 0; i < lazyWriter.clientStructs.length; i++) {
+    const partStructs = lazyWriter.clientStructs[i]
+    /**
+     * Works similarly to `writeStructs`
+     */
+    // write # encoded structs
+    encoding.writeVarUint(restEncoder, partStructs.written)
+    // write the rest of the fragment
+    encoding.writeUint8Array(restEncoder, partStructs.restEncoder)
+  }
+}
+
+/**
+ * @param {Uint8Array} update
+ * @param {typeof UpdateDecoderV2 | typeof UpdateDecoderV1} YDecoder
+ * @param {typeof UpdateEncoderV2 | typeof UpdateEncoderV1 } YEncoder
+ */
+export const convertUpdateFormat = (update, YDecoder, YEncoder) => {
+  const updateDecoder = new YDecoder(decoding.createDecoder(update))
+  const lazyDecoder = new LazyStructReader(updateDecoder, false)
+  const updateEncoder = new YEncoder()
+  const lazyWriter = new LazyStructWriter(updateEncoder)
+
+  for (let curr = lazyDecoder.curr; curr !== null; curr = lazyDecoder.next()) {
+    writeStructToLazyStructWriter(lazyWriter, curr, 0)
+  }
+  finishLazyStructWriting(lazyWriter)
+  const ds = readDeleteSet(updateDecoder)
+  writeDeleteSet(updateEncoder, ds)
+  return updateEncoder.toUint8Array()
+}
+
+/**
+ * @param {Uint8Array} update
+ */
+export const convertUpdateFormatV1ToV2 = update => convertUpdateFormat(update, UpdateDecoderV1, UpdateEncoderV2)
+
+/**
+ * @param {Uint8Array} update
+ */
+export const convertUpdateFormatV2ToV1 = update => convertUpdateFormat(update, UpdateDecoderV2, UpdateEncoderV1)

test.html

@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <title>Testing Yjs</title>
+</head>
+<body>
+  <script type="module" src="./dist/tests.js"></script>
+</body>
+</html>

test/TestSuite.coffee

@@ -1,208 +0,0 @@
-chai      = require('chai')
-expect    = chai.expect
-should    = chai.should()
-sinon     = require('sinon')
-sinonChai = require('sinon-chai')
-_         = require("underscore")
-
-chai.use(sinonChai)
-
-Connector = require "../../y-connectors/lib/y-test/y-test.coffee"
-
-module.exports = class Test
-  constructor: (@name_suffix = "")->
-    @number_of_test_cases_multiplier = 1
-    @repeat_this = 3 * @number_of_test_cases_multiplier
-    @doSomething_amount = 123 * @number_of_test_cases_multiplier
-    @number_of_engines = 5 + @number_of_test_cases_multiplier - 1
-
-    @time = 0 # denotes to the time when run was started
-    @ops = 0 # number of operations (used with @time)
-    @time_now = 0 # current time
-
-    @debug = false
-
-    @reinitialize()
-
-  reinitialize: ()->
-    @users = []
-    for i in [0...@number_of_engines]
-      u = @makeNewUser (i+@name_suffix)
-      for user in @users
-        u.getConnector().join(user.getConnector()) # TODO: change the test-connector to make this more convenient
-      @users.push u
-    @initUsers?(@users[0])
-    @flushAll()
-
-  # is called by implementing class
-  makeNewUser: (user)->
-    user.HB.setManualGarbageCollect()
-    user
-
-  getSomeUser: ()->
-    i = _.random 0, (@users.length-1)
-    @users[i]
-
-  getRandomText: (chars, min_length = 0)->
-    chars ?= "abcdefghijklmnopqrstuvwxyz"
-    length = _.random min_length, 10
-    #length = 1
-    nextchar = chars[(_.random 0, (chars.length-1))]
-    text = ""
-    _(length).times ()-> text += nextchar
-    text
-
-  getRandomObject: ()->
-    result = {}
-    key1 = @getRandomKey()
-    key2 = @getRandomKey()
-    val1 = @getRandomText()
-    val2 = null
-    if _.random(0,1) is 1
-      val2 = @getRandomObject()
-    else
-      val2 = @getRandomText()
-    result[key1] = val1
-    result[key2] = val2
-    result
-
-  getRandomKey: ()->
-    @getRandomText [1,2,'x','y'], 1 # only 4 keys
-
-  getGeneratingFunctions: (user_num)=>
-    types = @users[user_num].types
-    [
-        f : (y)=> # INSERT TEXT
-          y
-          pos = _.random 0, (y.val().length-1)
-          y.insert pos, @getRandomText()
-          null
-        types: [types.String]
-      ,
-        f : (y)-> # DELETE TEXT
-          if y.val().length > 0
-            pos = _.random 0, (y.val().length-1) # TODO: put here also arbitrary number (test behaviour in error cases)
-            length = _.random 0, (y.val().length - pos)
-            ops1 = y.delete pos, length
-          undefined
-        types : [types.String]
-    ]
-  getRandomRoot: (user_num)->
-    throw new Error "overwrite me!"
-
-  getContent: (user_num)->
-    throw new Error "overwrite me!"
-
-  generateRandomOp: (user_num)=>
-    y = @getRandomRoot(user_num)
-    choices = @getGeneratingFunctions(user_num).filter (gf)->
-      _.some gf.types, (type)->
-        y instanceof type
-
-    if choices.length is 0
-      console.dir(y)
-      throw new Error "You forgot to specify a test generation methot for this Operation! (#{y.type})"
-    i = _.random 0, (choices.length-1)
-    choices[i].f y
-
-  applyRandomOp: (user_num)=>
-    user = @users[user_num]
-    user.getConnector().flushOneRandom()
-
-  doSomething: ()->
-    user_num = _.random (@number_of_engines-1)
-    choices = [@applyRandomOp, @generateRandomOp]
-    choice = _.random (choices.length-1)
-    choices[choice](user_num)
-
-  flushAll: (final)->
-    # TODO:!!
-    final = false
-    if @users.length <= 1 or not final
-      for user,user_number in @users
-        user.getConnector().flushAll()
-    else
-      for user,user_number in @users[1..]
-        user.getConnector().flushAll()
-      ops = @users[1].getHistoryBuffer()._encode @users[0].HB.getOperationCounter()
-      @users[0].engine.applyOpsCheckDouble ops
-
-
-
-  compareAll: (test_number)->
-    @flushAll(true)
-
-    @time += (new Date()).getTime() - @time_now
-
-    number_of_created_operations = 0
-    for i in [0...(@users.length)]
-      number_of_created_operations += @users[i].getConnector().getOpsInExecutionOrder().length
-    @ops += number_of_created_operations*@users.length
-
-    ops_per_msek = Math.floor(@ops/@time)
-    if test_number? # and @debug
-      console.log "#{test_number}/#{@repeat_this}: #{number_of_created_operations} were created and applied on (#{@users.length}) users ops in a different order." + " Over all we consumed #{@ops} operations in #{@time/1000} seconds (#{ops_per_msek} ops/msek)."
-
-    for i in [0...(@users.length-1)]
-      if @debug
-        if not _.isEqual @getContent(i), @getContent(i+1)
-          printOpsInExecutionOrder = (otnumber, otherotnumber)=>
-            ops = _.filter @users[otnumber].getConnector().getOpsInExecutionOrder(), (o)->
-              typeof o.uid.op_name isnt 'string' and o.uid.creator isnt '_'
-            for s,j in ops
-              console.log "op#{j} = " + (JSON.stringify s)
-            console.log ""
-            s = "ops = ["
-            for o,j in ops
-              if j isnt 0
-                s += ", "
-              s += "op#{j}"
-            s += "]"
-            console.log s
-            console.log "@test_user.engine.applyOps ops"
-            console.log "expect(@test_user.val('name').val()).to.equal(\"#{@users[otherotnumber].val('name').val()}\")"
-            ops
-          console.log ""
-          console.log "Found an OT Puzzle!"
-          console.log "OT states:"
-          for u,j in @users
-            console.log "OT#{j}: "+u.val('name').val()
-          console.log "\nOT execution order (#{i},#{i+1}):"
-          printOpsInExecutionOrder i, i+1
-          console.log ""
-          ops = printOpsInExecutionOrder i+1, i
-
-          console.log ""
-      expect(@getContent(i)).to.deep.equal(@getContent(i+1))
-
-  run: ()->
-    if @debug
-      console.log ''
-    for times in [1..@repeat_this]
-      @time_now = (new Date).getTime()
-      for i in [1..Math.floor(@doSomething_amount/2)]
-        @doSomething()
-      @flushAll(false)
-      for u in @users
-        u.HB.emptyGarbage()
-      for i in [1..Math.floor(@doSomething_amount/2)]
-        @doSomething()
-
-      @compareAll(times)
-      @testHBencoding()
-      if times isnt @repeat_this
-        @reinitialize()
-
-  testHBencoding: ()->
-    # in case of JsonFramework, every user will create its JSON first! therefore, the testusers id must be small than all the others (see InsertType)
-    @users[@users.length] = @makeNewUser (-1) # this does not want to join with anymody
-
-    @users[@users.length-1].HB.renewStateVector @users[0].HB.getOperationCounter()
-    @users[@users.length-1].engine.applyOps @users[0].HB._encode()
-
-    #if @getContent(@users.length-1) isnt @getContent(0)
-    #  console.log "testHBencoding:"
-    #  console.log "Unprocessed ops first: #{@users[0].engine.unprocessed_ops.length}"
-    #  console.log "Unprocessed ops last: #{@users[@users.length-1].engine.unprocessed_ops.length}"
-    expect(@getContent(@users.length-1)).to.deep.equal(@getContent(0))
-

tests/doc.tests.js

@@ -0,0 +1,247 @@
+
+import * as Y from '../src/index.js'
+import * as t from 'lib0/testing'
+
+/**
+ * Client id should be changed when an instance receives updates from another client using the same client id.
+ *
+ * @param {t.TestCase} tc
+ */
+export const testClientIdDuplicateChange = tc => {
+  const doc1 = new Y.Doc()
+  doc1.clientID = 0
+  const doc2 = new Y.Doc()
+  doc2.clientID = 0
+  t.assert(doc2.clientID === doc1.clientID)
+  doc1.getArray('a').insert(0, [1, 2])
+  Y.applyUpdate(doc2, Y.encodeStateAsUpdate(doc1))
+  t.assert(doc2.clientID !== doc1.clientID)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testGetTypeEmptyId = tc => {
+  const doc1 = new Y.Doc()
+  doc1.getText('').insert(0, 'h')
+  doc1.getText().insert(1, 'i')
+  const doc2 = new Y.Doc()
+  Y.applyUpdate(doc2, Y.encodeStateAsUpdate(doc1))
+  t.assert(doc2.getText().toString() === 'hi')
+  t.assert(doc2.getText('').toString() === 'hi')
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testToJSON = tc => {
+  const doc = new Y.Doc()
+  t.compare(doc.toJSON(), {}, 'doc.toJSON yields empty object')
+
+  const arr = doc.getArray('array')
+  arr.push(['test1'])
+  t.compare(arr.toJSON(), ['test1'])
+
+  const map = doc.getMap('map')
+  map.set('k1', 'v1')
+  const map2 = new Y.Map()
+  map.set('k2', map2)
+  map2.set('m2k1', 'm2v1')
+
+  t.compare(doc.toJSON(), {
+    array: ['test1'],
+    map: {
+      k1: 'v1',
+      k2: {
+        m2k1: 'm2v1'
+      }
+    }
+  }, 'doc.toJSON has array and recursive map')
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testSubdoc = tc => {
+  const doc = new Y.Doc()
+  doc.load() // doesn't do anything
+  {
+    /**
+     * @type {Array<any>|null}
+     */
+    let event = /** @type {any} */ (null)
+    doc.on('subdocs', subdocs => {
+      event = [Array.from(subdocs.added).map(x => x.guid), Array.from(subdocs.removed).map(x => x.guid), Array.from(subdocs.loaded).map(x => x.guid)]
+    })
+    const subdocs = doc.getMap('mysubdocs')
+    const docA = new Y.Doc({ guid: 'a' })
+    docA.load()
+    subdocs.set('a', docA)
+    t.compare(event, [['a'], [], ['a']])
+
+    event = null
+    subdocs.get('a').load()
+    t.assert(event === null)
+
+    event = null
+    subdocs.get('a').destroy()
+    t.compare(event, [['a'], ['a'], []])
+    subdocs.get('a').load()
+    t.compare(event, [[], [], ['a']])
+
+    subdocs.set('b', new Y.Doc({ guid: 'a', shouldLoad: false }))
+    t.compare(event, [['a'], [], []])
+    subdocs.get('b').load()
+    t.compare(event, [[], [], ['a']])
+
+    const docC = new Y.Doc({ guid: 'c' })
+    docC.load()
+    subdocs.set('c', docC)
+    t.compare(event, [['c'], [], ['c']])
+
+    t.compare(Array.from(doc.getSubdocGuids()), ['a', 'c'])
+  }
+
+  const doc2 = new Y.Doc()
+  {
+    t.compare(Array.from(doc2.getSubdocs()), [])
+    /**
+     * @type {Array<any>|null}
+     */
+    let event = /** @type {any} */ (null)
+    doc2.on('subdocs', subdocs => {
+      event = [Array.from(subdocs.added).map(d => d.guid), Array.from(subdocs.removed).map(d => d.guid), Array.from(subdocs.loaded).map(d => d.guid)]
+    })
+    Y.applyUpdate(doc2, Y.encodeStateAsUpdate(doc))
+    t.compare(event, [['a', 'a', 'c'], [], []])
+
+    doc2.getMap('mysubdocs').get('a').load()
+    t.compare(event, [[], [], ['a']])
+
+    t.compare(Array.from(doc2.getSubdocGuids()), ['a', 'c'])
+
+    doc2.getMap('mysubdocs').delete('a')
+    t.compare(event, [[], ['a'], []])
+    t.compare(Array.from(doc2.getSubdocGuids()), ['a', 'c'])
+  }
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testSubdocLoadEdgeCases = tc => {
+  const ydoc = new Y.Doc()
+  const yarray = ydoc.getArray()
+  const subdoc1 = new Y.Doc()
+  /**
+   * @type {any}
+   */
+  let lastEvent = null
+  ydoc.on('subdocs', event => {
+    lastEvent = event
+  })
+  yarray.insert(0, [subdoc1])
+  t.assert(subdoc1.shouldLoad)
+  t.assert(subdoc1.autoLoad === false)
+  t.assert(lastEvent !== null && lastEvent.loaded.has(subdoc1))
+  t.assert(lastEvent !== null && lastEvent.added.has(subdoc1))
+  // destroy and check whether lastEvent adds it again to added (it shouldn't)
+  subdoc1.destroy()
+  const subdoc2 = yarray.get(0)
+  t.assert(subdoc1 !== subdoc2)
+  t.assert(lastEvent !== null && lastEvent.added.has(subdoc2))
+  t.assert(lastEvent !== null && !lastEvent.loaded.has(subdoc2))
+  // load
+  subdoc2.load()
+  t.assert(lastEvent !== null && !lastEvent.added.has(subdoc2))
+  t.assert(lastEvent !== null && lastEvent.loaded.has(subdoc2))
+  // apply from remote
+  const ydoc2 = new Y.Doc()
+  ydoc2.on('subdocs', event => {
+    lastEvent = event
+  })
+  Y.applyUpdate(ydoc2, Y.encodeStateAsUpdate(ydoc))
+  const subdoc3 = ydoc2.getArray().get(0)
+  t.assert(subdoc3.shouldLoad === false)
+  t.assert(subdoc3.autoLoad === false)
+  t.assert(lastEvent !== null && lastEvent.added.has(subdoc3))
+  t.assert(lastEvent !== null && !lastEvent.loaded.has(subdoc3))
+  // load
+  subdoc3.load()
+  t.assert(subdoc3.shouldLoad)
+  t.assert(lastEvent !== null && !lastEvent.added.has(subdoc3))
+  t.assert(lastEvent !== null && lastEvent.loaded.has(subdoc3))
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testSubdocLoadEdgeCasesAutoload = tc => {
+  const ydoc = new Y.Doc()
+  const yarray = ydoc.getArray()
+  const subdoc1 = new Y.Doc({ autoLoad: true })
+  /**
+   * @type {any}
+   */
+  let lastEvent = null
+  ydoc.on('subdocs', event => {
+    lastEvent = event
+  })
+  yarray.insert(0, [subdoc1])
+  t.assert(subdoc1.shouldLoad)
+  t.assert(subdoc1.autoLoad)
+  t.assert(lastEvent !== null && lastEvent.loaded.has(subdoc1))
+  t.assert(lastEvent !== null && lastEvent.added.has(subdoc1))
+  // destroy and check whether lastEvent adds it again to added (it shouldn't)
+  subdoc1.destroy()
+  const subdoc2 = yarray.get(0)
+  t.assert(subdoc1 !== subdoc2)
+  t.assert(lastEvent !== null && lastEvent.added.has(subdoc2))
+  t.assert(lastEvent !== null && !lastEvent.loaded.has(subdoc2))
+  // load
+  subdoc2.load()
+  t.assert(lastEvent !== null && !lastEvent.added.has(subdoc2))
+  t.assert(lastEvent !== null && lastEvent.loaded.has(subdoc2))
+  // apply from remote
+  const ydoc2 = new Y.Doc()
+  ydoc2.on('subdocs', event => {
+    lastEvent = event
+  })
+  Y.applyUpdate(ydoc2, Y.encodeStateAsUpdate(ydoc))
+  const subdoc3 = ydoc2.getArray().get(0)
+  t.assert(subdoc1.shouldLoad)
+  t.assert(subdoc1.autoLoad)
+  t.assert(lastEvent !== null && lastEvent.added.has(subdoc3))
+  t.assert(lastEvent !== null && lastEvent.loaded.has(subdoc3))
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testSubdocsUndo = tc => {
+  const ydoc = new Y.Doc()
+  const elems = ydoc.getXmlFragment()
+  const undoManager = new Y.UndoManager(elems)
+  const subdoc = new Y.Doc()
+  // @ts-ignore
+  elems.insert(0, [subdoc])
+  undoManager.undo()
+  undoManager.redo()
+  t.assert(elems.length === 1)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testLoadDocs = async tc => {
+  const ydoc = new Y.Doc()
+  t.assert(ydoc.isLoaded === false)
+  let loadedEvent = false
+  ydoc.on('load', () => {
+    loadedEvent = true
+  })
+  ydoc.emit('load', [ydoc])
+  await ydoc.whenLoaded
+  t.assert(loadedEvent)
+  t.assert(ydoc.isLoaded)
+}

tests/encoding.tests.js

@@ -0,0 +1,111 @@
+import * as t from 'lib0/testing'
+import * as promise from 'lib0/promise'
+
+import {
+  contentRefs,
+  readContentBinary,
+  readContentDeleted,
+  readContentString,
+  readContentJSON,
+  readContentEmbed,
+  readContentType,
+  readContentFormat,
+  readContentAny,
+  readContentDoc,
+  readContentMove,
+  Doc,
+  PermanentUserData,
+  encodeStateAsUpdate,
+  applyUpdate
+} from '../src/internals.js'
+
+import * as Y from '../src/index.js'
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testStructReferences = tc => {
+  t.assert(contentRefs.length === 12)
+  // contentRefs[0] is reserved for GC
+  t.assert(contentRefs[1] === readContentDeleted)
+  t.assert(contentRefs[2] === readContentJSON) // TODO: deprecate content json?
+  t.assert(contentRefs[3] === readContentBinary)
+  t.assert(contentRefs[4] === readContentString)
+  t.assert(contentRefs[5] === readContentEmbed)
+  t.assert(contentRefs[6] === readContentFormat)
+  t.assert(contentRefs[7] === readContentType)
+  t.assert(contentRefs[8] === readContentAny)
+  t.assert(contentRefs[9] === readContentDoc)
+  // contentRefs[10] is reserved for Skip structs
+  t.assert(contentRefs[11] === readContentMove)
+}
+
+/**
+ * There is some custom encoding/decoding happening in PermanentUserData.
+ * This is why it landed here.
+ *
+ * @param {t.TestCase} tc
+ */
+export const testPermanentUserData = async tc => {
+  const ydoc1 = new Doc()
+  const ydoc2 = new Doc()
+  const pd1 = new PermanentUserData(ydoc1)
+  const pd2 = new PermanentUserData(ydoc2)
+  pd1.setUserMapping(ydoc1, ydoc1.clientID, 'user a')
+  pd2.setUserMapping(ydoc2, ydoc2.clientID, 'user b')
+  ydoc1.getText().insert(0, 'xhi')
+  ydoc1.getText().delete(0, 1)
+  ydoc2.getText().insert(0, 'hxxi')
+  ydoc2.getText().delete(1, 2)
+  await promise.wait(10)
+  applyUpdate(ydoc2, encodeStateAsUpdate(ydoc1))
+  applyUpdate(ydoc1, encodeStateAsUpdate(ydoc2))
+
+  // now sync a third doc with same name as doc1 and then create PermanentUserData
+  const ydoc3 = new Doc()
+  applyUpdate(ydoc3, encodeStateAsUpdate(ydoc1))
+  const pd3 = new PermanentUserData(ydoc3)
+  pd3.setUserMapping(ydoc3, ydoc3.clientID, 'user a')
+}
+
+/**
+ * Reported here: https://github.com/yjs/yjs/issues/308
+ * @param {t.TestCase} tc
+ */
+export const testDiffStateVectorOfUpdateIsEmpty = tc => {
+  const ydoc = new Y.Doc()
+  /**
+   * @type {null | Uint8Array}
+   */
+  let sv = /* any */ (null)
+  ydoc.getText().insert(0, 'a')
+  ydoc.on('update', update => {
+    sv = Y.encodeStateVectorFromUpdate(update)
+  })
+  // should produce an update with an empty state vector (because previous ops are missing)
+  ydoc.getText().insert(0, 'a')
+  t.assert(sv !== null && sv.byteLength === 1 && sv[0] === 0)
+}
+
+/**
+ * Reported here: https://github.com/yjs/yjs/issues/308
+ * @param {t.TestCase} tc
+ */
+export const testDiffStateVectorOfUpdateIgnoresSkips = tc => {
+  const ydoc = new Y.Doc()
+  /**
+   * @type {Array<Uint8Array>}
+   */
+  const updates = []
+  ydoc.on('update', update => {
+    updates.push(update)
+  })
+  ydoc.getText().insert(0, 'a')
+  ydoc.getText().insert(0, 'b')
+  ydoc.getText().insert(0, 'c')
+  const update13 = Y.mergeUpdates([updates[0], updates[2]])
+  const sv = Y.encodeStateVectorFromUpdate(update13)
+  const state = Y.decodeStateVector(sv)
+  t.assert(state.get(ydoc.clientID) === 1)
+  t.assert(state.size === 1)
+}

tests/index.js

@@ -0,0 +1,28 @@
+
+import * as map from './y-map.tests.js'
+import * as array from './y-array.tests.js'
+import * as text from './y-text.tests.js'
+import * as xml from './y-xml.tests.js'
+import * as encoding from './encoding.tests.js'
+import * as undoredo from './undo-redo.tests.js'
+import * as compatibility from './compatibility.tests.js'
+import * as doc from './doc.tests.js'
+import * as snapshot from './snapshot.tests.js'
+import * as updates from './updates.tests.js'
+import * as relativePositions from './relativePositions.tests.js'
+
+import { runTests } from 'lib0/testing'
+import { isBrowser, isNode } from 'lib0/environment'
+import * as log from 'lib0/logging'
+
+if (isBrowser) {
+  log.createVConsole(document.body)
+}
+runTests({
+  doc, map, array, text, xml, encoding, undoredo, compatibility, snapshot, updates, relativePositions
+}).then(success => {
+  /* istanbul ignore next */
+  if (isNode) {
+    process.exit(success ? 0 : 1)
+  }
+})

tests/relativePositions.tests.js

@@ -0,0 +1,104 @@
+
+import * as Y from '../src/index.js'
+import * as t from 'lib0/testing'
+
+/**
+ * @param {Y.Text} ytext
+ */
+const checkRelativePositions = ytext => {
+  // test if all positions are encoded and restored correctly
+  for (let i = 0; i < ytext.length; i++) {
+    // for all types of associations..
+    for (let assoc = -1; assoc < 2; assoc++) {
+      const rpos = Y.createRelativePositionFromTypeIndex(ytext, i, assoc)
+      const encodedRpos = Y.encodeRelativePosition(rpos)
+      const decodedRpos = Y.decodeRelativePosition(encodedRpos)
+      const absPos = /** @type {Y.AbsolutePosition} */ (Y.createAbsolutePositionFromRelativePosition(decodedRpos, /** @type {Y.Doc} */ (ytext.doc)))
+      t.assert(absPos.index === i)
+      t.assert(absPos.assoc === assoc)
+    }
+  }
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRelativePositionCase1 = tc => {
+  const ydoc = new Y.Doc()
+  const ytext = ydoc.getText()
+  ytext.insert(0, '1')
+  ytext.insert(0, 'abc')
+  ytext.insert(0, 'z')
+  ytext.insert(0, 'y')
+  ytext.insert(0, 'x')
+  checkRelativePositions(ytext)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRelativePositionCase2 = tc => {
+  const ydoc = new Y.Doc()
+  const ytext = ydoc.getText()
+  ytext.insert(0, 'abc')
+  checkRelativePositions(ytext)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRelativePositionCase3 = tc => {
+  const ydoc = new Y.Doc()
+  const ytext = ydoc.getText()
+  ytext.insert(0, 'abc')
+  ytext.insert(0, '1')
+  ytext.insert(0, 'xyz')
+  checkRelativePositions(ytext)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRelativePositionCase4 = tc => {
+  const ydoc = new Y.Doc()
+  const ytext = ydoc.getText()
+  ytext.insert(0, '1')
+  checkRelativePositions(ytext)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRelativePositionCase5 = tc => {
+  const ydoc = new Y.Doc()
+  const ytext = ydoc.getText()
+  ytext.insert(0, '2')
+  ytext.insert(0, '1')
+  checkRelativePositions(ytext)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRelativePositionCase6 = tc => {
+  const ydoc = new Y.Doc()
+  const ytext = ydoc.getText()
+  checkRelativePositions(ytext)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRelativePositionAssociationDifference = tc => {
+  const ydoc = new Y.Doc()
+  const ytext = ydoc.getText()
+  ytext.insert(0, '2')
+  ytext.insert(0, '1')
+  const rposRight = Y.createRelativePositionFromTypeIndex(ytext, 1, 0)
+  const rposLeft = Y.createRelativePositionFromTypeIndex(ytext, 1, -1)
+  ytext.insert(1, 'x')
+  const posRight = Y.createAbsolutePositionFromRelativePosition(rposRight, ydoc)
+  const posLeft = Y.createAbsolutePositionFromRelativePosition(rposLeft, ydoc)
+  t.assert(posRight != null && posRight.index === 2)
+  t.assert(posLeft != null && posLeft.index === 1)
+}

tests/snapshot.tests.js

@@ -0,0 +1,171 @@
+import * as Y from '../src/index.js'
+import * as t from 'lib0/testing'
+import { init } from './testHelper.js'
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testBasicRestoreSnapshot = tc => {
+  const doc = new Y.Doc({ gc: false })
+  doc.getArray('array').insert(0, ['hello'])
+  const snap = Y.snapshot(doc)
+  doc.getArray('array').insert(1, ['world'])
+
+  const docRestored = Y.createDocFromSnapshot(doc, snap)
+
+  t.compare(docRestored.getArray('array').toArray(), ['hello'])
+  t.compare(doc.getArray('array').toArray(), ['hello', 'world'])
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testEmptyRestoreSnapshot = tc => {
+  const doc = new Y.Doc({ gc: false })
+  const snap = Y.snapshot(doc)
+  snap.sv.set(9999, 0)
+  doc.getArray().insert(0, ['world'])
+
+  const docRestored = Y.createDocFromSnapshot(doc, snap)
+
+  t.compare(docRestored.getArray().toArray(), [])
+  t.compare(doc.getArray().toArray(), ['world'])
+
+  // now this snapshot reflects the latest state. It shoult still work.
+  const snap2 = Y.snapshot(doc)
+  const docRestored2 = Y.createDocFromSnapshot(doc, snap2)
+  t.compare(docRestored2.getArray().toArray(), ['world'])
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRestoreSnapshotWithSubType = tc => {
+  const doc = new Y.Doc({ gc: false })
+  doc.getArray('array').insert(0, [new Y.Map()])
+  const subMap = doc.getArray('array').get(0)
+  subMap.set('key1', 'value1')
+
+  const snap = Y.snapshot(doc)
+  subMap.set('key2', 'value2')
+
+  const docRestored = Y.createDocFromSnapshot(doc, snap)
+
+  t.compare(docRestored.getArray('array').toJSON(), [{
+    key1: 'value1'
+  }])
+  t.compare(doc.getArray('array').toJSON(), [{
+    key1: 'value1',
+    key2: 'value2'
+  }])
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRestoreDeletedItem1 = tc => {
+  const doc = new Y.Doc({ gc: false })
+  doc.getArray('array').insert(0, ['item1', 'item2'])
+
+  const snap = Y.snapshot(doc)
+  doc.getArray('array').delete(0)
+
+  const docRestored = Y.createDocFromSnapshot(doc, snap)
+
+  t.compare(docRestored.getArray('array').toArray(), ['item1', 'item2'])
+  t.compare(doc.getArray('array').toArray(), ['item2'])
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRestoreLeftItem = tc => {
+  const doc = new Y.Doc({ gc: false })
+  doc.getArray('array').insert(0, ['item1'])
+  doc.getMap('map').set('test', 1)
+  doc.getArray('array').insert(0, ['item0'])
+
+  const snap = Y.snapshot(doc)
+  doc.getArray('array').delete(1)
+
+  const docRestored = Y.createDocFromSnapshot(doc, snap)
+
+  t.compare(docRestored.getArray('array').toArray(), ['item0', 'item1'])
+  t.compare(doc.getArray('array').toArray(), ['item0'])
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testDeletedItemsBase = tc => {
+  const doc = new Y.Doc({ gc: false })
+  doc.getArray('array').insert(0, ['item1'])
+  doc.getArray('array').delete(0)
+  const snap = Y.snapshot(doc)
+  doc.getArray('array').insert(0, ['item0'])
+
+  const docRestored = Y.createDocFromSnapshot(doc, snap)
+
+  t.compare(docRestored.getArray('array').toArray(), [])
+  t.compare(doc.getArray('array').toArray(), ['item0'])
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testDeletedItems2 = tc => {
+  const doc = new Y.Doc({ gc: false })
+  doc.getArray('array').insert(0, ['item1', 'item2', 'item3'])
+  doc.getArray('array').delete(1)
+  const snap = Y.snapshot(doc)
+  doc.getArray('array').insert(0, ['item0'])
+
+  const docRestored = Y.createDocFromSnapshot(doc, snap)
+
+  t.compare(docRestored.getArray('array').toArray(), ['item1', 'item3'])
+  t.compare(doc.getArray('array').toArray(), ['item0', 'item1', 'item3'])
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testDependentChanges = tc => {
+  const { array0, array1, testConnector } = init(tc, { users: 2 })
+
+  if (!array0.doc) {
+    throw new Error('no document 0')
+  }
+  if (!array1.doc) {
+    throw new Error('no document 1')
+  }
+
+  /**
+   * @type {Y.Doc}
+   */
+  const doc0 = array0.doc
+  /**
+   * @type {Y.Doc}
+   */
+  const doc1 = array1.doc
+
+  doc0.gc = false
+  doc1.gc = false
+
+  array0.insert(0, ['user1item1'])
+  testConnector.syncAll()
+  array1.insert(1, ['user2item1'])
+  testConnector.syncAll()
+
+  const snap = Y.snapshot(array0.doc)
+
+  array0.insert(2, ['user1item2'])
+  testConnector.syncAll()
+  array1.insert(3, ['user2item2'])
+  testConnector.syncAll()
+
+  const docRestored0 = Y.createDocFromSnapshot(array0.doc, snap)
+  t.compare(docRestored0.getArray('array').toArray(), ['user1item1', 'user2item1'])
+
+  const docRestored1 = Y.createDocFromSnapshot(array1.doc, snap)
+  t.compare(docRestored1.getArray('array').toArray(), ['user1item1', 'user2item1'])
+}

tests/testHelper.js

@@ -0,0 +1,515 @@
+
+import * as t from 'lib0/testing'
+import * as prng from 'lib0/prng'
+import * as encoding from 'lib0/encoding'
+import * as decoding from 'lib0/decoding'
+import * as syncProtocol from 'y-protocols/sync'
+import * as object from 'lib0/object'
+import * as Y from '../src/index.js'
+export * from '../src/index.js'
+
+if (typeof window !== 'undefined') {
+  // @ts-ignore
+  window.Y = Y // eslint-disable-line
+}
+
+/**
+ * @param {TestYInstance} y // publish message created by `y` to all other online clients
+ * @param {Uint8Array} m
+ */
+const broadcastMessage = (y, m) => {
+  if (y.tc.onlineConns.has(y)) {
+    y.tc.onlineConns.forEach(remoteYInstance => {
+      if (remoteYInstance !== y) {
+        remoteYInstance._receive(m, y)
+      }
+    })
+  }
+}
+
+export let useV2 = false
+
+export const encV1 = {
+  encodeStateAsUpdate: Y.encodeStateAsUpdate,
+  mergeUpdates: Y.mergeUpdates,
+  applyUpdate: Y.applyUpdate,
+  logUpdate: Y.logUpdate,
+  updateEventName: 'update',
+  diffUpdate: Y.diffUpdate
+}
+
+export const encV2 = {
+  encodeStateAsUpdate: Y.encodeStateAsUpdateV2,
+  mergeUpdates: Y.mergeUpdatesV2,
+  applyUpdate: Y.applyUpdateV2,
+  logUpdate: Y.logUpdateV2,
+  updateEventName: 'updateV2',
+  diffUpdate: Y.diffUpdateV2
+}
+
+export let enc = encV1
+
+const useV1Encoding = () => {
+  useV2 = false
+  enc = encV1
+}
+
+const useV2Encoding = () => {
+  console.error('sync protocol doesnt support v2 protocol yet, fallback to v1 encoding') // @Todo
+  useV2 = false
+  enc = encV1
+}
+
+export class TestYInstance extends Y.Doc {
+  /**
+   * @param {TestConnector} testConnector
+   * @param {number} clientID
+   */
+  constructor (testConnector, clientID) {
+    super()
+    this.userID = clientID // overwriting clientID
+    /**
+     * @type {TestConnector}
+     */
+    this.tc = testConnector
+    /**
+     * @type {Map<TestYInstance, Array<Uint8Array>>}
+     */
+    this.receiving = new Map()
+    testConnector.allConns.add(this)
+    /**
+     * The list of received updates.
+     * We are going to merge them later using Y.mergeUpdates and check if the resulting document is correct.
+     * @type {Array<Uint8Array>}
+     */
+    this.updates = []
+    // set up observe on local model
+    this.on(enc.updateEventName, /** @param {Uint8Array} update @param {any} origin */ (update, origin) => {
+      if (origin !== testConnector) {
+        const encoder = encoding.createEncoder()
+        syncProtocol.writeUpdate(encoder, update)
+        broadcastMessage(this, encoding.toUint8Array(encoder))
+        this.updates.push(update)
+      }
+    })
+    this.connect()
+  }
+
+  /**
+   * Disconnect from TestConnector.
+   */
+  disconnect () {
+    this.receiving = new Map()
+    this.tc.onlineConns.delete(this)
+  }
+
+  /**
+   * Append yourself to the list of known Y instances in testconnector.
+   * Also initiate sync with all clients.
+   */
+  connect () {
+    if (!this.tc.onlineConns.has(this)) {
+      this.tc.onlineConns.add(this)
+      const encoder = encoding.createEncoder()
+      syncProtocol.writeSyncStep1(encoder, this)
+      // publish SyncStep1
+      broadcastMessage(this, encoding.toUint8Array(encoder))
+      this.tc.onlineConns.forEach(remoteYInstance => {
+        if (remoteYInstance !== this) {
+          // remote instance sends instance to this instance
+          const encoder = encoding.createEncoder()
+          syncProtocol.writeSyncStep1(encoder, remoteYInstance)
+          this._receive(encoding.toUint8Array(encoder), remoteYInstance)
+        }
+      })
+    }
+  }
+
+  /**
+   * Receive a message from another client. This message is only appended to the list of receiving messages.
+   * TestConnector decides when this client actually reads this message.
+   *
+   * @param {Uint8Array} message
+   * @param {TestYInstance} remoteClient
+   */
+  _receive (message, remoteClient) {
+    let messages = this.receiving.get(remoteClient)
+    if (messages === undefined) {
+      messages = []
+      this.receiving.set(remoteClient, messages)
+    }
+    messages.push(message)
+  }
+}
+
+/**
+ * Keeps track of TestYInstances.
+ *
+ * The TestYInstances add/remove themselves from the list of connections maiained in this object.
+ * I think it makes sense. Deal with it.
+ */
+export class TestConnector {
+  /**
+   * @param {prng.PRNG} gen
+   */
+  constructor (gen) {
+    /**
+     * @type {Set<TestYInstance>}
+     */
+    this.allConns = new Set()
+    /**
+     * @type {Set<TestYInstance>}
+     */
+    this.onlineConns = new Set()
+    /**
+     * @type {prng.PRNG}
+     */
+    this.prng = gen
+  }
+
+  /**
+   * Create a new Y instance and add it to the list of connections
+   * @param {number} clientID
+   */
+  createY (clientID) {
+    return new TestYInstance(this, clientID)
+  }
+
+  /**
+   * Choose random connection and flush a random message from a random sender.
+   *
+   * If this function was unable to flush a message, because there are no more messages to flush, it returns false. true otherwise.
+   * @return {boolean}
+   */
+  flushRandomMessage () {
+    const gen = this.prng
+    const conns = Array.from(this.onlineConns).filter(conn => conn.receiving.size > 0)
+    if (conns.length > 0) {
+      const receiver = prng.oneOf(gen, conns)
+      const [sender, messages] = prng.oneOf(gen, Array.from(receiver.receiving))
+      const m = messages.shift()
+      if (messages.length === 0) {
+        receiver.receiving.delete(sender)
+      }
+      if (m === undefined) {
+        return this.flushRandomMessage()
+      }
+      const encoder = encoding.createEncoder()
+      // console.log('receive (' + sender.userID + '->' + receiver.userID + '):\n', syncProtocol.stringifySyncMessage(decoding.createDecoder(m), receiver))
+      // do not publish data created when this function is executed (could be ss2 or update message)
+      syncProtocol.readSyncMessage(decoding.createDecoder(m), encoder, receiver, receiver.tc)
+      if (encoding.length(encoder) > 0) {
+        // send reply message
+        sender._receive(encoding.toUint8Array(encoder), receiver)
+      }
+      {
+        // If update message, add the received message to the list of received messages
+        const decoder = decoding.createDecoder(m)
+        const messageType = decoding.readVarUint(decoder)
+        switch (messageType) {
+          case syncProtocol.messageYjsUpdate:
+          case syncProtocol.messageYjsSyncStep2:
+            receiver.updates.push(decoding.readVarUint8Array(decoder))
+            break
+        }
+      }
+      return true
+    }
+    return false
+  }
+
+  /**
+   * @return {boolean} True iff this function actually flushed something
+   */
+  flushAllMessages () {
+    let didSomething = false
+    while (this.flushRandomMessage()) {
+      didSomething = true
+    }
+    return didSomething
+  }
+
+  reconnectAll () {
+    this.allConns.forEach(conn => conn.connect())
+  }
+
+  disconnectAll () {
+    this.allConns.forEach(conn => conn.disconnect())
+  }
+
+  syncAll () {
+    this.reconnectAll()
+    this.flushAllMessages()
+  }
+
+  /**
+   * @return {boolean} Whether it was possible to disconnect a randon connection.
+   */
+  disconnectRandom () {
+    if (this.onlineConns.size === 0) {
+      return false
+    }
+    prng.oneOf(this.prng, Array.from(this.onlineConns)).disconnect()
+    return true
+  }
+
+  /**
+   * @return {boolean} Whether it was possible to reconnect a random connection.
+   */
+  reconnectRandom () {
+    /**
+     * @type {Array<TestYInstance>}
+     */
+    const reconnectable = []
+    this.allConns.forEach(conn => {
+      if (!this.onlineConns.has(conn)) {
+        reconnectable.push(conn)
+      }
+    })
+    if (reconnectable.length === 0) {
+      return false
+    }
+    prng.oneOf(this.prng, reconnectable).connect()
+    return true
+  }
+}
+
+/**
+ * @template T
+ * @param {t.TestCase} tc
+ * @param {{users?:number}} conf
+ * @param {InitTestObjectCallback<T>} [initTestObject]
+ * @return {{testObjects:Array<any>,testConnector:TestConnector,users:Array<TestYInstance>,array0:Y.Array<any>,array1:Y.Array<any>,array2:Y.Array<any>,map0:Y.Map<any>,map1:Y.Map<any>,map2:Y.Map<any>,map3:Y.Map<any>,text0:Y.Text,text1:Y.Text,text2:Y.Text,xml0:Y.XmlElement,xml1:Y.XmlElement,xml2:Y.XmlElement}}
+ */
+export const init = (tc, { users = 5 } = {}, initTestObject) => {
+  /**
+   * @type {Object<string,any>}
+   */
+  const result = {
+    users: []
+  }
+  const gen = tc.prng
+  // choose an encoding approach at random
+  if (prng.bool(gen)) {
+    useV2Encoding()
+  } else {
+    useV1Encoding()
+  }
+
+  const testConnector = new TestConnector(gen)
+  result.testConnector = testConnector
+  for (let i = 0; i < users; i++) {
+    const y = testConnector.createY(i)
+    y.clientID = i
+    result.users.push(y)
+    result['array' + i] = y.getArray('array')
+    result['map' + i] = y.getMap('map')
+    result['xml' + i] = y.get('xml', Y.XmlElement)
+    result['text' + i] = y.getText('text')
+  }
+  testConnector.syncAll()
+  result.testObjects = result.users.map(initTestObject || (() => null))
+  useV1Encoding()
+  return /** @type {any} */ (result)
+}
+
+/**
+ * 1. reconnect and flush all
+ * 2. user 0 gc
+ * 3. get type content
+ * 4. disconnect & reconnect all (so gc is propagated)
+ * 5. compare os, ds, ss
+ *
+ * @param {Array<TestYInstance>} users
+ */
+export const compare = users => {
+  users.forEach(u => u.connect())
+  while (users[0].tc.flushAllMessages()) {} // eslint-disable-line
+  // For each document, merge all received document updates with Y.mergeUpdates and create a new document which will be added to the list of "users"
+  // This ensures that mergeUpdates works correctly
+  const mergedDocs = users.map(user => {
+    const ydoc = new Y.Doc()
+    enc.applyUpdate(ydoc, enc.mergeUpdates(user.updates))
+    return ydoc
+  })
+  users.push(.../** @type {any} */(mergedDocs))
+  const userArrayValues = users.map(u => u.getArray('array').toJSON())
+  const userMapValues = users.map(u => u.getMap('map').toJSON())
+  const userXmlValues = users.map(u => u.get('xml', Y.XmlElement).toString())
+  const userTextValues = users.map(u => u.getText('text').toDelta())
+  for (const u of users) {
+    t.assert(u.store.pendingDs === null)
+    t.assert(u.store.pendingStructs === null)
+  }
+  // Test Array iterator
+  t.compare(users[0].getArray('array').toArray(), Array.from(users[0].getArray('array')))
+  // Test Map iterator
+  const ymapkeys = Array.from(users[0].getMap('map').keys())
+  t.assert(ymapkeys.length === Object.keys(userMapValues[0]).length)
+  ymapkeys.forEach(key => t.assert(object.hasProperty(userMapValues[0], key)))
+  /**
+   * @type {Object<string,any>}
+   */
+  const mapRes = {}
+  for (const [k, v] of users[0].getMap('map')) {
+    mapRes[k] = v instanceof Y.AbstractType ? v.toJSON() : v
+  }
+  t.compare(userMapValues[0], mapRes)
+  // Compare all users
+  for (let i = 0; i < users.length - 1; i++) {
+    t.compare(userArrayValues[i].length, users[i].getArray('array').length)
+    t.compare(userArrayValues[i], userArrayValues[i + 1])
+    t.compare(userMapValues[i], userMapValues[i + 1])
+    t.compare(userXmlValues[i], userXmlValues[i + 1])
+    t.compare(userTextValues[i].map(/** @param {any} a */ a => typeof a.insert === 'string' ? a.insert : ' ').join('').length, users[i].getText('text').length)
+    t.compare(userTextValues[i], userTextValues[i + 1], '', (constructor, a, b) => {
+      if (a instanceof Y.AbstractType) {
+        t.compare(a.toJSON(), b.toJSON())
+      } else if (a !== b) {
+        t.fail('Deltas dont match')
+      }
+      return true
+    })
+    t.compare(Y.encodeStateVector(users[i]), Y.encodeStateVector(users[i + 1]))
+    compareDS(Y.createDeleteSetFromStructStore(users[i].store), Y.createDeleteSetFromStructStore(users[i + 1].store))
+    compareStructStores(users[i].store, users[i + 1].store)
+    // @todo
+    // test list-iterator
+    // console.log('dutiraneduiaentdr', users[0].getArray('array')._searchMarker)
+    /*
+    {
+      const user = users[0]
+      user.transact(tr => {
+        const type = user.getArray('array')
+        Y.useSearchMarker(tr, type, type.length, walker => {
+          for (let i = type.length; i >= 0; i--) {
+            const otherWalker = new Y.ListIterator(type)
+            otherWalker.forward(tr, walker.index)
+            otherWalker.forward(tr, 0)
+            walker.forward(tr, 0)
+            t.assert(walker.index === i)
+            t.assert(walker.left === otherWalker.left)
+            t.assert(walker.right === otherWalker.right)
+            t.assert(walker.nextItem === otherWalker.nextItem)
+            t.assert(walker.reachedEnd === otherWalker.reachedEnd)
+            if (i > 0) {
+              walker.backward(tr, 1)
+            }
+          }
+        })
+      })
+    }
+    */
+  }
+  users.map(u => u.destroy())
+}
+
+/**
+ * @param {Y.Item?} a
+ * @param {Y.Item?} b
+ * @return {boolean}
+ */
+export const compareItemIDs = (a, b) => a === b || (a !== null && b != null && Y.compareIDs(a.id, b.id))
+
+/**
+ * @param {import('../src/internals').StructStore} ss1
+ * @param {import('../src/internals').StructStore} ss2
+ */
+export const compareStructStores = (ss1, ss2) => {
+  t.assert(ss1.clients.size === ss2.clients.size)
+  for (const [client, structs1] of ss1.clients) {
+    const structs2 = /** @type {Array<Y.AbstractStruct>} */ (ss2.clients.get(client))
+    t.assert(structs2 !== undefined && structs1.length === structs2.length)
+    for (let i = 0; i < structs1.length; i++) {
+      const s1 = structs1[i]
+      const s2 = structs2[i]
+      // checks for abstract struct
+      if (
+        s1.constructor !== s2.constructor ||
+        !Y.compareIDs(s1.id, s2.id) ||
+        s1.deleted !== s2.deleted ||
+        // @ts-ignore
+        s1.length !== s2.length
+      ) {
+        t.fail('Structs dont match')
+      }
+      if (s1 instanceof Y.Item) {
+        if (
+          !(s2 instanceof Y.Item) ||
+          !((s1.left === null && s2.left === null) || (s1.left !== null && s2.left !== null && Y.compareIDs(s1.left.lastId, s2.left.lastId))) ||
+          !compareItemIDs(s1.right, s2.right) ||
+          !Y.compareIDs(s1.origin, s2.origin) ||
+          !Y.compareIDs(s1.rightOrigin, s2.rightOrigin) ||
+          s1.parentSub !== s2.parentSub
+        ) {
+          return t.fail('Items dont match')
+        }
+        // make sure that items are connected correctly
+        t.assert(s1.left === null || s1.left.right === s1)
+        t.assert(s1.right === null || s1.right.left === s1)
+        t.assert(s2.left === null || s2.left.right === s2)
+        t.assert(s2.right === null || s2.right.left === s2)
+      }
+    }
+  }
+}
+
+/**
+ * @param {import('../src/internals').DeleteSet} ds1
+ * @param {import('../src/internals').DeleteSet} ds2
+ */
+export const compareDS = (ds1, ds2) => {
+  t.assert(ds1.clients.size === ds2.clients.size)
+  ds1.clients.forEach((deleteItems1, client) => {
+    const deleteItems2 = /** @type {Array<import('../src/internals').DeleteItem>} */ (ds2.clients.get(client))
+    t.assert(deleteItems2 !== undefined && deleteItems1.length === deleteItems2.length)
+    for (let i = 0; i < deleteItems1.length; i++) {
+      const di1 = deleteItems1[i]
+      const di2 = deleteItems2[i]
+      if (di1.clock !== di2.clock || di1.len !== di2.len) {
+        t.fail('DeleteSets dont match')
+      }
+    }
+  })
+}
+
+/**
+ * @template T
+ * @callback InitTestObjectCallback
+ * @param {TestYInstance} y
+ * @return {T}
+ */
+
+/**
+ * @template T
+ * @param {t.TestCase} tc
+ * @param {Array<function(Y.Doc,prng.PRNG,T):void>} mods
+ * @param {number} iterations
+ * @param {InitTestObjectCallback<T>} [initTestObject]
+ */
+export const applyRandomTests = (tc, mods, iterations, initTestObject) => {
+  const gen = tc.prng
+  const result = init(tc, { users: 5 }, initTestObject)
+  const { testConnector, users } = result
+  for (let i = 0; i < iterations; i++) {
+    if (prng.int32(gen, 0, 100) <= 2) {
+      // 2% chance to disconnect/reconnect a random user
+      if (prng.bool(gen)) {
+        testConnector.disconnectRandom()
+      } else {
+        testConnector.reconnectRandom()
+      }
+    } else if (prng.int32(gen, 0, 100) <= 1) {
+      // 1% chance to flush all
+      testConnector.flushAllMessages()
+    } else if (prng.int32(gen, 0, 100) <= 50) {
+      // 50% chance to flush a random message
+      testConnector.flushRandomMessage()
+    }
+    const user = prng.int32(gen, 0, users.length - 1)
+    const test = prng.oneOf(gen, mods)
+    test(users[user], gen, result.testObjects[user])
+  }
+  compare(users)
+  return result
+}

tests/undo-redo.tests.js

@@ -0,0 +1,374 @@
+import { init, compare, applyRandomTests, Doc, UndoManager } from './testHelper.js' // eslint-disable-line
+
+import * as Y from '../src/index.js'
+import * as t from 'lib0/testing'
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testUndoText = tc => {
+  const { testConnector, text0, text1 } = init(tc, { users: 3 })
+  const undoManager = new Y.UndoManager(text0)
+
+  // items that are added & deleted in the same transaction won't be undo
+  text0.insert(0, 'test')
+  text0.delete(0, 4)
+  undoManager.undo()
+  t.assert(text0.toString() === '')
+
+  // follow redone items
+  text0.insert(0, 'a')
+  undoManager.stopCapturing()
+  text0.delete(0, 1)
+  undoManager.stopCapturing()
+  undoManager.undo()
+  t.assert(text0.toString() === 'a')
+  undoManager.undo()
+  t.assert(text0.toString() === '')
+
+  text0.insert(0, 'abc')
+  text1.insert(0, 'xyz')
+  testConnector.syncAll()
+  undoManager.undo()
+  t.assert(text0.toString() === 'xyz')
+  undoManager.redo()
+  t.assert(text0.toString() === 'abcxyz')
+  testConnector.syncAll()
+  text1.delete(0, 1)
+  testConnector.syncAll()
+  undoManager.undo()
+  t.assert(text0.toString() === 'xyz')
+  undoManager.redo()
+  t.assert(text0.toString() === 'bcxyz')
+  // test marks
+  text0.format(1, 3, { bold: true })
+  t.compare(text0.toDelta(), [{ insert: 'b' }, { insert: 'cxy', attributes: { bold: true } }, { insert: 'z' }])
+  undoManager.undo()
+  t.compare(text0.toDelta(), [{ insert: 'bcxyz' }])
+  undoManager.redo()
+  t.compare(text0.toDelta(), [{ insert: 'b' }, { insert: 'cxy', attributes: { bold: true } }, { insert: 'z' }])
+}
+
+/**
+ * Test case to fix #241
+ * @param {t.TestCase} tc
+ */
+export const testDoubleUndo = tc => {
+  const doc = new Y.Doc()
+  const text = doc.getText()
+  text.insert(0, '1221')
+
+  const manager = new Y.UndoManager(text)
+
+  text.insert(2, '3')
+  text.insert(3, '3')
+
+  manager.undo()
+  manager.undo()
+
+  text.insert(2, '3')
+
+  t.compareStrings(text.toString(), '12321')
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testUndoMap = tc => {
+  const { testConnector, map0, map1 } = init(tc, { users: 2 })
+  map0.set('a', 0)
+  const undoManager = new Y.UndoManager(map0)
+  map0.set('a', 1)
+  undoManager.undo()
+  t.assert(map0.get('a') === 0)
+  undoManager.redo()
+  t.assert(map0.get('a') === 1)
+  // testing sub-types and if it can restore a whole type
+  const subType = new Y.Map()
+  map0.set('a', subType)
+  subType.set('x', 42)
+  t.compare(map0.toJSON(), /** @type {any} */ ({ a: { x: 42 } }))
+  undoManager.undo()
+  t.assert(map0.get('a') === 1)
+  undoManager.redo()
+  t.compare(map0.toJSON(), /** @type {any} */ ({ a: { x: 42 } }))
+  testConnector.syncAll()
+  // if content is overwritten by another user, undo operations should be skipped
+  map1.set('a', 44)
+  testConnector.syncAll()
+  undoManager.undo()
+  t.assert(map0.get('a') === 44)
+  undoManager.redo()
+  t.assert(map0.get('a') === 44)
+
+  // test setting value multiple times
+  map0.set('b', 'initial')
+  undoManager.stopCapturing()
+  map0.set('b', 'val1')
+  map0.set('b', 'val2')
+  undoManager.stopCapturing()
+  undoManager.undo()
+  t.assert(map0.get('b') === 'initial')
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testUndoArray = tc => {
+  const { testConnector, array0, array1 } = init(tc, { users: 3 })
+  const undoManager = new Y.UndoManager(array0)
+  array0.insert(0, [1, 2, 3])
+  array1.insert(0, [4, 5, 6])
+  testConnector.syncAll()
+  t.compare(array0.toArray(), [1, 2, 3, 4, 5, 6])
+  undoManager.undo()
+  t.compare(array0.toArray(), [4, 5, 6])
+  undoManager.redo()
+  t.compare(array0.toArray(), [1, 2, 3, 4, 5, 6])
+  testConnector.syncAll()
+  array1.delete(0, 1) // user1 deletes [1]
+  testConnector.syncAll()
+  undoManager.undo()
+  t.compare(array0.toArray(), [4, 5, 6])
+  undoManager.redo()
+  t.compare(array0.toArray(), [2, 3, 4, 5, 6])
+  array0.delete(0, 5)
+  // test nested structure
+  const ymap = new Y.Map()
+  array0.insert(0, [ymap])
+  t.compare(array0.toJSON(), [{}])
+  undoManager.stopCapturing()
+  ymap.set('a', 1)
+  t.compare(array0.toJSON(), [{ a: 1 }])
+  undoManager.undo()
+  t.compare(array0.toJSON(), [{}])
+  undoManager.undo()
+  t.compare(array0.toJSON(), [2, 3, 4, 5, 6])
+  undoManager.redo()
+  t.compare(array0.toJSON(), [{}])
+  undoManager.redo()
+  t.compare(array0.toJSON(), [{ a: 1 }])
+  testConnector.syncAll()
+  array1.get(0).set('b', 2)
+  testConnector.syncAll()
+  t.compare(array0.toJSON(), [{ a: 1, b: 2 }])
+  undoManager.undo()
+  t.compare(array0.toJSON(), [{ b: 2 }])
+  undoManager.undo()
+  t.compare(array0.toJSON(), [2, 3, 4, 5, 6])
+  undoManager.redo()
+  t.compare(array0.toJSON(), [{ b: 2 }])
+  undoManager.redo()
+  t.compare(array0.toJSON(), [{ a: 1, b: 2 }])
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testUndoXml = tc => {
+  const { xml0 } = init(tc, { users: 3 })
+  const undoManager = new Y.UndoManager(xml0)
+  const child = new Y.XmlElement('p')
+  xml0.insert(0, [child])
+  const textchild = new Y.XmlText('content')
+  child.insert(0, [textchild])
+  t.assert(xml0.toString() === '<undefined><p>content</p></undefined>')
+  // format textchild and revert that change
+  undoManager.stopCapturing()
+  textchild.format(3, 4, { bold: {} })
+  t.assert(xml0.toString() === '<undefined><p>con<bold>tent</bold></p></undefined>')
+  undoManager.undo()
+  t.assert(xml0.toString() === '<undefined><p>content</p></undefined>')
+  undoManager.redo()
+  t.assert(xml0.toString() === '<undefined><p>con<bold>tent</bold></p></undefined>')
+  xml0.delete(0, 1)
+  t.assert(xml0.toString() === '<undefined></undefined>')
+  undoManager.undo()
+  t.assert(xml0.toString() === '<undefined><p>con<bold>tent</bold></p></undefined>')
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testUndoEvents = tc => {
+  const { text0 } = init(tc, { users: 3 })
+  const undoManager = new Y.UndoManager(text0)
+  let counter = 0
+  let receivedMetadata = -1
+  undoManager.on('stack-item-added', /** @param {any} event */ event => {
+    t.assert(event.type != null)
+    t.assert(event.changedParentTypes != null && event.changedParentTypes.has(text0))
+    event.stackItem.meta.set('test', counter++)
+  })
+  undoManager.on('stack-item-popped', /** @param {any} event */ event => {
+    t.assert(event.type != null)
+    t.assert(event.changedParentTypes != null && event.changedParentTypes.has(text0))
+    receivedMetadata = event.stackItem.meta.get('test')
+  })
+  text0.insert(0, 'abc')
+  undoManager.undo()
+  t.assert(receivedMetadata === 0)
+  undoManager.redo()
+  t.assert(receivedMetadata === 1)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testTrackClass = tc => {
+  const { users, text0 } = init(tc, { users: 3 })
+  // only track origins that are numbers
+  const undoManager = new Y.UndoManager(text0, { trackedOrigins: new Set([Number]) })
+  users[0].transact(() => {
+    text0.insert(0, 'abc')
+  }, 42)
+  t.assert(text0.toString() === 'abc')
+  undoManager.undo()
+  t.assert(text0.toString() === '')
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testTypeScope = tc => {
+  const { array0 } = init(tc, { users: 3 })
+  // only track origins that are numbers
+  const text0 = new Y.Text()
+  const text1 = new Y.Text()
+  array0.insert(0, [text0, text1])
+  const undoManager = new Y.UndoManager(text0)
+  const undoManagerBoth = new Y.UndoManager([text0, text1])
+  text1.insert(0, 'abc')
+  t.assert(undoManager.undoStack.length === 0)
+  t.assert(undoManagerBoth.undoStack.length === 1)
+  t.assert(text1.toString() === 'abc')
+  undoManager.undo()
+  t.assert(text1.toString() === 'abc')
+  undoManagerBoth.undo()
+  t.assert(text1.toString() === '')
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testUndoInEmbed = tc => {
+  const { text0 } = init(tc, { users: 3 })
+  const undoManager = new Y.UndoManager(text0)
+  const nestedText = new Y.Text('initial text')
+  undoManager.stopCapturing()
+  text0.insertEmbed(0, nestedText, { bold: true })
+  t.assert(nestedText.toString() === 'initial text')
+  undoManager.stopCapturing()
+  nestedText.delete(0, nestedText.length)
+  nestedText.insert(0, 'other text')
+  t.assert(nestedText.toString() === 'other text')
+  undoManager.undo()
+  t.assert(nestedText.toString() === 'initial text')
+  undoManager.undo()
+  t.assert(text0.length === 0)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testUndoDeleteFilter = tc => {
+  /**
+   * @type {Array<Y.Map<any>>}
+   */
+  const array0 = /** @type {any} */ (init(tc, { users: 3 }).array0)
+  const undoManager = new Y.UndoManager(array0, { deleteFilter: item => !(item instanceof Y.Item) || (item.content instanceof Y.ContentType && item.content.type._map.size === 0) })
+  const map0 = new Y.Map()
+  map0.set('hi', 1)
+  const map1 = new Y.Map()
+  array0.insert(0, [map0, map1])
+  undoManager.undo()
+  t.assert(array0.length === 1)
+  array0.get(0)
+  t.assert(Array.from(array0.get(0).keys()).length === 1)
+}
+
+/**
+ * This issue has been reported in https://discuss.yjs.dev/t/undomanager-with-external-updates/454/6
+ * @param {t.TestCase} tc
+ */
+export const testUndoUntilChangePerformed = tc => {
+  const doc = new Y.Doc()
+  const doc2 = new Y.Doc()
+  doc.on('update', update => Y.applyUpdate(doc2, update))
+  doc2.on('update', update => Y.applyUpdate(doc, update))
+
+  const yArray = doc.getArray('array')
+  const yArray2 = doc2.getArray('array')
+  const yMap = new Y.Map()
+  yMap.set('hello', 'world')
+  yArray.push([yMap])
+  const yMap2 = new Y.Map()
+  yMap2.set('key', 'value')
+  yArray.push([yMap2])
+
+  const undoManager = new Y.UndoManager([yArray], { trackedOrigins: new Set([doc.clientID]) })
+  const undoManager2 = new Y.UndoManager([doc2.get('array')], { trackedOrigins: new Set([doc2.clientID]) })
+
+  Y.transact(doc, () => yMap2.set('key', 'value modified'), doc.clientID)
+  undoManager.stopCapturing()
+  Y.transact(doc, () => yMap.set('hello', 'world modified'), doc.clientID)
+  Y.transact(doc2, () => yArray2.delete(0), doc2.clientID)
+  undoManager2.undo()
+  undoManager.undo()
+  t.compareStrings(yMap2.get('key'), 'value')
+}
+
+/**
+ * This issue has been reported in https://github.com/yjs/yjs/issues/317
+ * @param {t.TestCase} tc
+ */
+export const testUndoNestedUndoIssue = tc => {
+  const doc = new Y.Doc({ gc: false })
+  const design = doc.getMap()
+  const undoManager = new Y.UndoManager(design, { captureTimeout: 0 })
+
+  /**
+   * @type {Y.Map<any>}
+   */
+  const text = new Y.Map()
+
+  const blocks1 = new Y.Array()
+  const blocks1block = new Y.Map()
+
+  doc.transact(() => {
+    blocks1block.set('text', 'Type Something')
+    blocks1.push([blocks1block])
+    text.set('blocks', blocks1block)
+    design.set('text', text)
+  })
+
+  const blocks2 = new Y.Array()
+  const blocks2block = new Y.Map()
+  doc.transact(() => {
+    blocks2block.set('text', 'Something')
+    blocks2.push([blocks2block])
+    text.set('blocks', blocks2block)
+  })
+
+  const blocks3 = new Y.Array()
+  const blocks3block = new Y.Map()
+  doc.transact(() => {
+    blocks3block.set('text', 'Something Else')
+    blocks3.push([blocks3block])
+    text.set('blocks', blocks3block)
+  })
+
+  t.compare(design.toJSON(), { text: { blocks: { text: 'Something Else' } } })
+  undoManager.undo()
+  t.compare(design.toJSON(), { text: { blocks: { text: 'Something' } } })
+  undoManager.undo()
+  t.compare(design.toJSON(), { text: { blocks: { text: 'Type Something' } } })
+  undoManager.undo()
+  t.compare(design.toJSON(), { })
+  undoManager.redo()
+  t.compare(design.toJSON(), { text: { blocks: { text: 'Type Something' } } })
+  undoManager.redo()
+  t.compare(design.toJSON(), { text: { blocks: { text: 'Something' } } })
+  undoManager.redo()
+  t.compare(design.toJSON(), { text: { blocks: { text: 'Something Else' } } })
+}

tests/updates.tests.js

@@ -0,0 +1,288 @@
+import * as t from 'lib0/testing'
+import { init, compare } from './testHelper.js' // eslint-disable-line
+import * as Y from '../src/index.js'
+import { readClientsStructRefs, readDeleteSet, UpdateDecoderV2, UpdateEncoderV2, writeDeleteSet } from '../src/internals.js'
+import * as encoding from 'lib0/encoding'
+import * as decoding from 'lib0/decoding'
+
+/**
+ * @typedef {Object} Enc
+ * @property {function(Array<Uint8Array>):Uint8Array} Enc.mergeUpdates
+ * @property {function(Y.Doc):Uint8Array} Enc.encodeStateAsUpdate
+ * @property {function(Y.Doc, Uint8Array):void} Enc.applyUpdate
+ * @property {function(Uint8Array):void} Enc.logUpdate
+ * @property {function(Uint8Array):{from:Map<number,number>,to:Map<number,number>}} Enc.parseUpdateMeta
+ * @property {function(Y.Doc):Uint8Array} Enc.encodeStateVector
+ * @property {function(Uint8Array):Uint8Array} Enc.encodeStateVectorFromUpdate
+ * @property {string} Enc.updateEventName
+ * @property {string} Enc.description
+ * @property {function(Uint8Array, Uint8Array):Uint8Array} Enc.diffUpdate
+ */
+
+/**
+ * @type {Enc}
+ */
+const encV1 = {
+  mergeUpdates: Y.mergeUpdates,
+  encodeStateAsUpdate: Y.encodeStateAsUpdate,
+  applyUpdate: Y.applyUpdate,
+  logUpdate: Y.logUpdate,
+  parseUpdateMeta: Y.parseUpdateMeta,
+  encodeStateVectorFromUpdate: Y.encodeStateVectorFromUpdate,
+  encodeStateVector: Y.encodeStateVector,
+  updateEventName: 'update',
+  description: 'V1',
+  diffUpdate: Y.diffUpdate
+}
+
+/**
+ * @type {Enc}
+ */
+const encV2 = {
+  mergeUpdates: Y.mergeUpdatesV2,
+  encodeStateAsUpdate: Y.encodeStateAsUpdateV2,
+  applyUpdate: Y.applyUpdateV2,
+  logUpdate: Y.logUpdateV2,
+  parseUpdateMeta: Y.parseUpdateMetaV2,
+  encodeStateVectorFromUpdate: Y.encodeStateVectorFromUpdateV2,
+  encodeStateVector: Y.encodeStateVector,
+  updateEventName: 'updateV2',
+  description: 'V2',
+  diffUpdate: Y.diffUpdateV2
+}
+
+/**
+ * @type {Enc}
+ */
+const encDoc = {
+  mergeUpdates: (updates) => {
+    const ydoc = new Y.Doc({ gc: false })
+    updates.forEach(update => {
+      Y.applyUpdateV2(ydoc, update)
+    })
+    return Y.encodeStateAsUpdateV2(ydoc)
+  },
+  encodeStateAsUpdate: Y.encodeStateAsUpdateV2,
+  applyUpdate: Y.applyUpdateV2,
+  logUpdate: Y.logUpdateV2,
+  parseUpdateMeta: Y.parseUpdateMetaV2,
+  encodeStateVectorFromUpdate: Y.encodeStateVectorFromUpdateV2,
+  encodeStateVector: Y.encodeStateVector,
+  updateEventName: 'updateV2',
+  description: 'Merge via Y.Doc',
+  /**
+   * @param {Uint8Array} update
+   * @param {Uint8Array} sv
+   */
+  diffUpdate: (update, sv) => {
+    const ydoc = new Y.Doc({ gc: false })
+    Y.applyUpdateV2(ydoc, update)
+    return Y.encodeStateAsUpdateV2(ydoc, sv)
+  }
+}
+
+const encoders = [encV1, encV2, encDoc]
+
+/**
+ * @param {Array<Y.Doc>} users
+ * @param {Enc} enc
+ */
+const fromUpdates = (users, enc) => {
+  const updates = users.map(user =>
+    enc.encodeStateAsUpdate(user)
+  )
+  const ydoc = new Y.Doc()
+  enc.applyUpdate(ydoc, enc.mergeUpdates(updates))
+  return ydoc
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testMergeUpdates = tc => {
+  const { users, array0, array1 } = init(tc, { users: 3 })
+
+  array0.insert(0, [1])
+  array1.insert(0, [2])
+
+  compare(users)
+  encoders.forEach(enc => {
+    const merged = fromUpdates(users, enc)
+    t.compareArrays(array0.toArray(), merged.getArray('array').toArray())
+  })
+}
+
+/**
+ * @param {Y.Doc} ydoc
+ * @param {Array<Uint8Array>} updates - expecting at least 4 updates
+ * @param {Enc} enc
+ * @param {boolean} hasDeletes
+ */
+const checkUpdateCases = (ydoc, updates, enc, hasDeletes) => {
+  const cases = []
+
+  // Case 1: Simple case, simply merge everything
+  cases.push(enc.mergeUpdates(updates))
+
+  // Case 2: Overlapping updates
+  cases.push(enc.mergeUpdates([
+    enc.mergeUpdates(updates.slice(2)),
+    enc.mergeUpdates(updates.slice(0, 2))
+  ]))
+
+  // Case 3: Overlapping updates
+  cases.push(enc.mergeUpdates([
+    enc.mergeUpdates(updates.slice(2)),
+    enc.mergeUpdates(updates.slice(1, 3)),
+    updates[0]
+  ]))
+
+  // Case 4: Separated updates (containing skips)
+  cases.push(enc.mergeUpdates([
+    enc.mergeUpdates([updates[0], updates[2]]),
+    enc.mergeUpdates([updates[1], updates[3]]),
+    enc.mergeUpdates(updates.slice(4))
+  ]))
+
+  // Case 5: overlapping with many duplicates
+  cases.push(enc.mergeUpdates(cases))
+
+  // const targetState = enc.encodeStateAsUpdate(ydoc)
+  // t.info('Target State: ')
+  // enc.logUpdate(targetState)
+
+  cases.forEach((mergedUpdates, i) => {
+    // t.info('State Case $' + i + ':')
+    // enc.logUpdate(updates)
+    const merged = new Y.Doc({ gc: false })
+    enc.applyUpdate(merged, mergedUpdates)
+    t.compareArrays(merged.getArray().toArray(), ydoc.getArray().toArray())
+    t.compare(enc.encodeStateVector(merged), enc.encodeStateVectorFromUpdate(mergedUpdates))
+
+    if (enc.updateEventName !== 'update') { // @todo should this also work on legacy updates?
+      for (let j = 1; j < updates.length; j++) {
+        const partMerged = enc.mergeUpdates(updates.slice(j))
+        const partMeta = enc.parseUpdateMeta(partMerged)
+        const targetSV = Y.encodeStateVectorFromUpdateV2(Y.mergeUpdatesV2(updates.slice(0, j)))
+        const diffed = enc.diffUpdate(mergedUpdates, targetSV)
+        const diffedMeta = enc.parseUpdateMeta(diffed)
+        t.compare(partMeta, diffedMeta)
+        {
+          // We can'd do the following
+          //  - t.compare(diffed, mergedDeletes)
+          // because diffed contains the set of all deletes.
+          // So we add all deletes from `diffed` to `partDeletes` and compare then
+          const decoder = decoding.createDecoder(diffed)
+          const updateDecoder = new UpdateDecoderV2(decoder)
+          readClientsStructRefs(updateDecoder, new Y.Doc())
+          const ds = readDeleteSet(updateDecoder)
+          const updateEncoder = new UpdateEncoderV2()
+          encoding.writeVarUint(updateEncoder.restEncoder, 0) // 0 structs
+          writeDeleteSet(updateEncoder, ds)
+          const deletesUpdate = updateEncoder.toUint8Array()
+          const mergedDeletes = Y.mergeUpdatesV2([deletesUpdate, partMerged])
+          if (!hasDeletes || enc !== encDoc) {
+            // deletes will almost definitely lead to different encoders because of the mergeStruct feature that is present in encDoc
+            t.compare(diffed, mergedDeletes)
+          }
+        }
+      }
+    }
+
+    const meta = enc.parseUpdateMeta(mergedUpdates)
+    meta.from.forEach((clock, client) => t.assert(clock === 0))
+    meta.to.forEach((clock, client) => {
+      const structs = /** @type {Array<Y.Item>} */ (merged.store.clients.get(client))
+      const lastStruct = structs[structs.length - 1]
+      t.assert(lastStruct.id.clock + lastStruct.length === clock)
+    })
+  })
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testMergeUpdates1 = tc => {
+  encoders.forEach((enc, i) => {
+    t.info(`Using encoder: ${enc.description}`)
+    const ydoc = new Y.Doc({ gc: false })
+    const updates = /** @type {Array<Uint8Array>} */ ([])
+    ydoc.on(enc.updateEventName, update => { updates.push(update) })
+
+    const array = ydoc.getArray()
+    array.insert(0, [1])
+    array.insert(0, [2])
+    array.insert(0, [3])
+    array.insert(0, [4])
+
+    checkUpdateCases(ydoc, updates, enc, false)
+  })
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testMergeUpdates2 = tc => {
+  encoders.forEach((enc, i) => {
+    t.info(`Using encoder: ${enc.description}`)
+    const ydoc = new Y.Doc({ gc: false })
+    const updates = /** @type {Array<Uint8Array>} */ ([])
+    ydoc.on(enc.updateEventName, update => { updates.push(update) })
+
+    const array = ydoc.getArray()
+    array.insert(0, [1, 2])
+    array.delete(1, 1)
+    array.insert(0, [3, 4])
+    array.delete(1, 2)
+
+    checkUpdateCases(ydoc, updates, enc, true)
+  })
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testMergePendingUpdates = tc => {
+  const yDoc = new Y.Doc()
+  /**
+   * @type {Array<Uint8Array>}
+   */
+  const serverUpdates = []
+  yDoc.on('update', (update, origin, c) => {
+    serverUpdates.splice(serverUpdates.length, 0, update)
+  })
+  const yText = yDoc.getText('textBlock')
+  yText.applyDelta([{ insert: 'r' }])
+  yText.applyDelta([{ insert: 'o' }])
+  yText.applyDelta([{ insert: 'n' }])
+  yText.applyDelta([{ insert: 'e' }])
+  yText.applyDelta([{ insert: 'n' }])
+
+  const yDoc1 = new Y.Doc()
+  Y.applyUpdate(yDoc1, serverUpdates[0])
+  const update1 = Y.encodeStateAsUpdate(yDoc1)
+
+  const yDoc2 = new Y.Doc()
+  Y.applyUpdate(yDoc2, update1)
+  Y.applyUpdate(yDoc2, serverUpdates[1])
+  const update2 = Y.encodeStateAsUpdate(yDoc2)
+
+  const yDoc3 = new Y.Doc()
+  Y.applyUpdate(yDoc3, update2)
+  Y.applyUpdate(yDoc3, serverUpdates[3])
+  const update3 = Y.encodeStateAsUpdate(yDoc3)
+
+  const yDoc4 = new Y.Doc()
+  Y.applyUpdate(yDoc4, update3)
+  Y.applyUpdate(yDoc4, serverUpdates[2])
+  const update4 = Y.encodeStateAsUpdate(yDoc4)
+
+  const yDoc5 = new Y.Doc()
+  Y.applyUpdate(yDoc5, update4)
+  Y.applyUpdate(yDoc5, serverUpdates[4])
+  // @ts-ignore
+  const update5 = Y.encodeStateAsUpdate(yDoc5) // eslint-disable-line
+
+  const yText5 = yDoc5.getText('textBlock')
+  t.compareStrings(yText5.toString(), 'nenor')
+}

tests/y-array.tests.js

@@ -0,0 +1,765 @@
+import { init, compare, applyRandomTests, Doc, AbstractType, TestConnector } from './testHelper.js' // eslint-disable-line
+
+import * as Y from '../src/index.js'
+import * as t from 'lib0/testing'
+import * as prng from 'lib0/prng'
+import * as math from 'lib0/math'
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testBasicUpdate = tc => {
+  const doc1 = new Y.Doc()
+  const doc2 = new Y.Doc()
+  doc1.getArray('array').insert(0, ['hi'])
+  const update = Y.encodeStateAsUpdate(doc1)
+  Y.applyUpdate(doc2, update)
+  t.compare(doc2.getArray('array').toArray(), ['hi'])
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testSlice = tc => {
+  const doc1 = new Y.Doc()
+  const arr = doc1.getArray('array')
+  arr.insert(0, [1, 2, 3])
+  t.compareArrays(arr.slice(0), [1, 2, 3])
+  t.compareArrays(arr.slice(1), [2, 3])
+  t.compareArrays(arr.slice(0, -1), [1, 2])
+  arr.insert(0, [0])
+  t.compareArrays(arr.slice(0), [0, 1, 2, 3])
+  t.compareArrays(arr.slice(0, 2), [0, 1])
+}
+
+/**
+ * Debugging yjs#297 - a critical bug connected to the search-marker approach
+ *
+ * @param {t.TestCase} tc
+ */
+export const testLengthIssue = tc => {
+  const doc1 = new Y.Doc()
+  const arr = doc1.getArray('array')
+  arr.push([0, 1, 2, 3])
+  arr.delete(0)
+  arr.insert(0, [0])
+  t.assert(arr.length === arr.toArray().length)
+  doc1.transact(() => {
+    arr.delete(1)
+    t.assert(arr.length === arr.toArray().length)
+    arr.insert(1, [1])
+    t.assert(arr.length === arr.toArray().length)
+    arr.delete(2)
+    t.assert(arr.length === arr.toArray().length)
+    arr.insert(2, [2])
+    t.assert(arr.length === arr.toArray().length)
+  })
+  t.assert(arr.length === arr.toArray().length)
+  arr.delete(1)
+  t.assert(arr.length === arr.toArray().length)
+  arr.insert(1, [1])
+  t.assert(arr.length === arr.toArray().length)
+}
+
+/**
+ * Debugging yjs#314
+ *
+ * @param {t.TestCase} tc
+ */
+export const testLengthIssue2 = tc => {
+  const doc = new Y.Doc()
+  const next = doc.getArray()
+  doc.transact(() => {
+    next.insert(0, ['group2'])
+  })
+  doc.transact(() => {
+    next.insert(1, ['rectangle3'])
+  })
+  doc.transact(() => {
+    next.delete(0)
+    next.insert(0, ['rectangle3'])
+  })
+  next.delete(1)
+  doc.transact(() => {
+    next.insert(1, ['ellipse4'])
+  })
+  doc.transact(() => {
+    next.insert(2, ['ellipse3'])
+  })
+  doc.transact(() => {
+    next.insert(3, ['ellipse2'])
+  })
+  doc.transact(() => {
+    doc.transact(() => {
+      t.fails(() => {
+        next.insert(5, ['rectangle2'])
+      })
+      next.insert(4, ['rectangle2'])
+    })
+    doc.transact(() => {
+      // this should not throw an error message
+      next.delete(4)
+    })
+  })
+  console.log(next.toArray())
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testDeleteInsert = tc => {
+  const { users, array0 } = init(tc, { users: 2 })
+  array0.delete(0, 0)
+  t.describe('Does not throw when deleting zero elements with position 0')
+  t.fails(() => {
+    array0.delete(1, 1)
+  })
+  array0.insert(0, ['A'])
+  array0.delete(1, 0)
+  t.describe('Does not throw when deleting zero elements with valid position 1')
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testInsertThreeElementsTryRegetProperty = tc => {
+  const { testConnector, users, array0, array1 } = init(tc, { users: 2 })
+  array0.insert(0, [1, true, false])
+  t.compare(array0.toJSON(), [1, true, false], '.toJSON() works')
+  testConnector.flushAllMessages()
+  t.compare(array1.toJSON(), [1, true, false], '.toJSON() works after sync')
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testConcurrentInsertWithThreeConflicts = tc => {
+  const { users, array0, array1, array2 } = init(tc, { users: 3 })
+  array0.insert(0, [0])
+  array1.insert(0, [1])
+  array2.insert(0, [2])
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testConcurrentInsertDeleteWithThreeConflicts = tc => {
+  const { testConnector, users, array0, array1, array2 } = init(tc, { users: 3 })
+  array0.insert(0, ['x', 'y', 'z'])
+  testConnector.flushAllMessages()
+  array0.insert(1, [0])
+  array1.delete(0)
+  array1.delete(1, 1)
+  array2.insert(1, [2])
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testInsertionsInLateSync = tc => {
+  const { testConnector, users, array0, array1, array2 } = init(tc, { users: 3 })
+  array0.insert(0, ['x', 'y'])
+  testConnector.flushAllMessages()
+  users[1].disconnect()
+  users[2].disconnect()
+  array0.insert(1, ['user0'])
+  array1.insert(1, ['user1'])
+  array2.insert(1, ['user2'])
+  users[1].connect()
+  users[2].connect()
+  testConnector.flushAllMessages()
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testDisconnectReallyPreventsSendingMessages = tc => {
+  const { testConnector, users, array0, array1 } = init(tc, { users: 3 })
+  array0.insert(0, ['x', 'y'])
+  testConnector.flushAllMessages()
+  users[1].disconnect()
+  users[2].disconnect()
+  array0.insert(1, ['user0'])
+  array1.insert(1, ['user1'])
+  t.compare(array0.toJSON(), ['x', 'user0', 'y'])
+  t.compare(array1.toJSON(), ['x', 'user1', 'y'])
+  users[1].connect()
+  users[2].connect()
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testDeletionsInLateSync = tc => {
+  const { testConnector, users, array0, array1 } = init(tc, { users: 2 })
+  array0.insert(0, ['x', 'y'])
+  testConnector.flushAllMessages()
+  users[1].disconnect()
+  array1.delete(1, 1)
+  array0.delete(0, 2)
+  users[1].connect()
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testInsertThenMergeDeleteOnSync = tc => {
+  const { testConnector, users, array0, array1 } = init(tc, { users: 2 })
+  array0.insert(0, ['x', 'y', 'z'])
+  testConnector.flushAllMessages()
+  users[0].disconnect()
+  array1.delete(0, 3)
+  users[0].connect()
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testInsertAndDeleteEvents = tc => {
+  const { array0, users } = init(tc, { users: 2 })
+  /**
+   * @type {Object<string,any>?}
+   */
+  let event = null
+  array0.observe(e => {
+    event = e
+  })
+  array0.insert(0, [0, 1, 2])
+  t.assert(event !== null)
+  event = null
+  array0.delete(0)
+  t.assert(event !== null)
+  event = null
+  array0.delete(0, 2)
+  t.assert(event !== null)
+  event = null
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testNestedObserverEvents = tc => {
+  const { array0, users } = init(tc, { users: 2 })
+  /**
+   * @type {Array<number>}
+   */
+  const vals = []
+  array0.observe(e => {
+    if (array0.length === 1) {
+      // inserting, will call this observer again
+      // we expect that this observer is called after this event handler finishedn
+      array0.insert(1, [1])
+      vals.push(0)
+    } else {
+      // this should be called the second time an element is inserted (above case)
+      vals.push(1)
+    }
+  })
+  array0.insert(0, [0])
+  t.compareArrays(vals, [0, 1])
+  t.compareArrays(array0.toArray(), [0, 1])
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testInsertAndDeleteEventsForTypes = tc => {
+  const { array0, users } = init(tc, { users: 2 })
+  /**
+   * @type {Object<string,any>|null}
+   */
+  let event = null
+  array0.observe(e => {
+    event = e
+  })
+  array0.insert(0, [new Y.Array()])
+  t.assert(event !== null)
+  event = null
+  array0.delete(0)
+  t.assert(event !== null)
+  event = null
+  compare(users)
+}
+
+/**
+ * This issue has been reported in https://discuss.yjs.dev/t/order-in-which-events-yielded-by-observedeep-should-be-applied/261/2
+ *
+ * Deep observers generate multiple events. When an array added at item at, say, position 0,
+ * and item 1 changed then the array-add event should fire first so that the change event
+ * path is correct. A array binding might lead to an inconsistent state otherwise.
+ *
+ * @param {t.TestCase} tc
+ */
+export const testObserveDeepEventOrder = tc => {
+  const { array0, users } = init(tc, { users: 2 })
+  /**
+   * @type {Array<any>}
+   */
+  let events = []
+  array0.observeDeep(e => {
+    events = e
+  })
+  array0.insert(0, [new Y.Map()])
+  users[0].transact(() => {
+    array0.get(0).set('a', 'a')
+    array0.insert(0, [0])
+  })
+  for (let i = 1; i < events.length; i++) {
+    t.assert(events[i - 1].path.length <= events[i].path.length, 'path size increases, fire top-level events first')
+  }
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testChangeEvent = tc => {
+  const { array0, users } = init(tc, { users: 2 })
+  /**
+   * @type {any}
+   */
+  let changes = null
+  array0.observe(e => {
+    changes = e.changes
+  })
+  const newArr = new Y.Array()
+  array0.insert(0, [newArr, 4, 'dtrn'])
+  t.assert(changes !== null && changes.added.size === 2 && changes.deleted.size === 0)
+  t.compare(changes.delta, [{ insert: [newArr, 4, 'dtrn'] }])
+  changes = null
+  array0.delete(0, 2)
+  t.assert(changes !== null && changes.added.size === 0 && changes.deleted.size === 2)
+  t.compare(changes.delta, [{ delete: 2 }])
+  changes = null
+  array0.insert(1, [0.1])
+  t.assert(changes !== null && changes.added.size === 1 && changes.deleted.size === 0)
+  t.compare(changes.delta, [{ retain: 1 }, { insert: [0.1] }])
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testInsertAndDeleteEventsForTypes2 = tc => {
+  const { array0, users } = init(tc, { users: 2 })
+  /**
+   * @type {Array<Object<string,any>>}
+   */
+  const events = []
+  array0.observe(e => {
+    events.push(e)
+  })
+  array0.insert(0, ['hi', new Y.Map()])
+  t.assert(events.length === 1, 'Event is triggered exactly once for insertion of two elements')
+  array0.delete(1)
+  t.assert(events.length === 2, 'Event is triggered exactly once for deletion')
+  compare(users)
+}
+
+/**
+ * This issue has been reported here https://github.com/yjs/yjs/issues/155
+ * @param {t.TestCase} tc
+ */
+export const testNewChildDoesNotEmitEventInTransaction = tc => {
+  const { array0, users } = init(tc, { users: 2 })
+  let fired = false
+  users[0].transact(() => {
+    const newMap = new Y.Map()
+    newMap.observe(() => {
+      fired = true
+    })
+    array0.insert(0, [newMap])
+    newMap.set('tst', 42)
+  })
+  t.assert(!fired, 'Event does not trigger')
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testGarbageCollector = tc => {
+  const { testConnector, users, array0 } = init(tc, { users: 3 })
+  array0.insert(0, ['x', 'y', 'z'])
+  testConnector.flushAllMessages()
+  users[0].disconnect()
+  array0.delete(0, 3)
+  users[0].connect()
+  testConnector.flushAllMessages()
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testEventTargetIsSetCorrectlyOnLocal = tc => {
+  const { array0, users } = init(tc, { users: 3 })
+  /**
+   * @type {any}
+   */
+  let event
+  array0.observe(e => {
+    event = e
+  })
+  array0.insert(0, ['stuff'])
+  t.assert(event.target === array0, '"target" property is set correctly')
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testEventTargetIsSetCorrectlyOnRemote = tc => {
+  const { testConnector, array0, array1, users } = init(tc, { users: 3 })
+  /**
+   * @type {any}
+   */
+  let event
+  array0.observe(e => {
+    event = e
+  })
+  array1.insert(0, ['stuff'])
+  testConnector.flushAllMessages()
+  t.assert(event.target === array0, '"target" property is set correctly')
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testMove = tc => {
+  {
+    // move in uninitialized type
+    const yarr = new Y.Array()
+    yarr.insert(0, [1, 2, 3])
+    yarr.move(1, 0)
+    // @ts-ignore
+    t.compare(yarr._prelimContent, [2, 1, 3])
+  }
+  const { array0, array1, users } = init(tc, { users: 3 })
+  /**
+   * @type {any}
+   */
+  let event0 = null
+  /**
+   * @type {any}
+   */
+  let event1 = null
+  array0.observe(event => {
+    event0 = event
+  })
+  array1.observe(event => {
+    event1 = event
+  })
+  array0.insert(0, [1, 2, 3])
+  array0.move(1, 0)
+  t.compare(array0.toArray(), [2, 1, 3])
+  t.compare(event0.delta, [{ insert: [2] }, { retain: 1 }, { delete: 1 }])
+  Y.applyUpdate(users[1], Y.encodeStateAsUpdate(users[0]))
+  t.compare(array1.toArray(), [2, 1, 3])
+  t.compare(event1.delta, [{ insert: [2, 1, 3] }])
+  array0.move(0, 2)
+  t.compare(array0.toArray(), [1, 2, 3])
+  t.compare(event0.delta, [{ delete: 1 }, { retain: 1 }, { insert: [2] }])
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testMove2 = tc => {
+  {
+    // move in uninitialized type
+    const yarr = new Y.Array()
+    yarr.insert(0, [1, 2])
+    yarr.move(1, 0)
+    // @ts-ignore
+    t.compare(yarr._prelimContent, [2, 1])
+  }
+  const { array0, array1, users } = init(tc, { users: 3 })
+  /**
+   * @type {any}
+   */
+  let event0 = null
+  /**
+   * @type {any}
+   */
+  let event1 = null
+  array0.observe(event => {
+    event0 = event
+  })
+  array1.observe(event => {
+    event1 = event
+  })
+  array0.insert(0, [1, 2])
+  array0.move(1, 0)
+  t.compare(array0.toArray(), [2, 1])
+  t.compare(event0.delta, [{ insert: [2] }, { retain: 1 }, { delete: 1 }])
+  Y.applyUpdate(users[1], Y.encodeStateAsUpdate(users[0]))
+  t.compare(array1.toArray(), [2, 1])
+  t.compare(event1.delta, [{ insert: [2, 1] }])
+  array0.move(0, 2)
+  t.compare(array0.toArray(), [1, 2])
+  t.compare(event0.delta, [{ delete: 1 }, { retain: 1 }, { insert: [2] }])
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testIteratingArrayContainingTypes = tc => {
+  const y = new Y.Doc()
+  const arr = y.getArray('arr')
+  const numItems = 10
+  for (let i = 0; i < numItems; i++) {
+    const map = new Y.Map()
+    map.set('value', i)
+    arr.push([map])
+  }
+  let cnt = 0
+  for (const item of arr) {
+    t.assert(item.get('value') === cnt++, 'value is correct')
+  }
+  y.destroy()
+}
+
+let _uniqueNumber = 0
+const getUniqueNumber = () => _uniqueNumber++
+
+/**
+ * @type {Array<function(Doc,prng.PRNG,any):void>}
+ *
+ * @todo to replace content to a separate data structure so we know that insert & returns work as expected!!!
+ */
+const arrayTransactions = [
+  function move (user, gen) {
+    const yarray = user.getArray('array')
+    if (yarray.length === 0) {
+      return
+    }
+    const pos = prng.int32(gen, 0, yarray.length - 1)
+    const newPos = prng.int32(gen, 0, yarray.length)
+    const oldContent = yarray.toArray()
+    yarray.move(pos, newPos)
+    const [x] = oldContent.splice(pos, 1)
+    oldContent.splice(pos < newPos ? newPos - 1 : newPos, 0, x)
+    t.compareArrays(yarray.toArray(), oldContent) // we want to make sure that fastSearch markers insert at the correct position
+  },
+  function insert (user, gen) {
+    const yarray = user.getArray('array')
+    const uniqueNumber = getUniqueNumber()
+    const content = []
+    const len = prng.int32(gen, 1, 4)
+    for (let i = 0; i < len; i++) {
+      content.push(uniqueNumber)
+    }
+    const pos = prng.int32(gen, 0, yarray.length)
+    const oldContent = yarray.toArray()
+    yarray.insert(pos, content)
+    oldContent.splice(pos, 0, ...content)
+    t.compareArrays(yarray.toArray(), oldContent) // we want to make sure that fastSearch markers insert at the correct position
+  },
+  function insertTypeArray (user, gen) {
+    const yarray = user.getArray('array')
+    const pos = prng.int32(gen, 0, yarray.length)
+    yarray.insert(pos, [new Y.Array()])
+    const array2 = yarray.get(pos)
+    array2.insert(0, [1, 2, 3, 4])
+  },
+  function insertTypeMap (user, gen) {
+    const yarray = user.getArray('array')
+    const pos = prng.int32(gen, 0, yarray.length)
+    yarray.insert(pos, [new Y.Map()])
+    const map = yarray.get(pos)
+    map.set('someprop', 42)
+    map.set('someprop', 43)
+    map.set('someprop', 44)
+  },
+  function insertTypeNull (user, gen) {
+    const yarray = user.getArray('array')
+    const pos = prng.int32(gen, 0, yarray.length)
+    yarray.insert(pos, [null])
+  },
+  function _delete (user, gen) {
+    const yarray = user.getArray('array')
+    const length = yarray.length
+    if (length > 0) {
+      let somePos = prng.int32(gen, 0, length - 1)
+      let delLength = prng.int32(gen, 1, math.min(2, length - somePos))
+      if (prng.bool(gen)) {
+        const type = yarray.get(somePos)
+        if (type instanceof Y.Array && type.length > 0) {
+          somePos = prng.int32(gen, 0, type.length - 1)
+          delLength = prng.int32(gen, 0, math.min(2, type.length - somePos))
+          type.delete(somePos, delLength)
+        }
+      } else {
+        const oldContent = yarray.toArray()
+        yarray.delete(somePos, delLength)
+        oldContent.splice(somePos, delLength)
+        t.compareArrays(yarray.toArray(), oldContent)
+      }
+    }
+  }
+]
+
+/**
+ * @param {Y.Doc} user
+ */
+const monitorArrayTestObject = user => {
+  /**
+   * @type {Array<any>}
+   */
+  const arr = []
+  const yarr = user.getArray('array')
+  yarr.observe(event => {
+    let currpos = 0
+    const delta = event.delta
+    for (let i = 0; i < delta.length; i++) {
+      const d = delta[i]
+      if (d.insert != null) {
+        arr.splice(currpos, 0, ...(/** @type {Array<any>} */ (d.insert)))
+        currpos += /** @type {Array<any>} */ (d.insert).length
+      } else if (d.retain != null) {
+        currpos += d.retain
+      } else {
+        arr.splice(currpos, d.delete)
+      }
+    }
+  })
+  return arr
+}
+
+/**
+ * @param {{ testObjects: Array<Array<any>>, users: Array<Y.Doc> }} cmp
+ */
+const compareTestobjects = cmp => {
+  const arrs = cmp.testObjects
+  for (let i = 0; i < arrs.length; i++) {
+    const type = cmp.users[i].getArray('array')
+    t.compareArrays(arrs[i], type.toArray())
+  }
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYarrayTests6 = tc => {
+  compareTestobjects(applyRandomTests(tc, arrayTransactions, 7, monitorArrayTestObject))
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYarrayTests40 = tc => {
+  applyRandomTests(tc, arrayTransactions, 40)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYarrayTests42 = tc => {
+  applyRandomTests(tc, arrayTransactions, 42)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYarrayTests43 = tc => {
+  applyRandomTests(tc, arrayTransactions, 43)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYarrayTests44 = tc => {
+  applyRandomTests(tc, arrayTransactions, 44)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYarrayTests45 = tc => {
+  applyRandomTests(tc, arrayTransactions, 45)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYarrayTests46 = tc => {
+  applyRandomTests(tc, arrayTransactions, 46)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYarrayTests300 = tc => {
+  applyRandomTests(tc, arrayTransactions, 300)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYarrayTests400 = tc => {
+  applyRandomTests(tc, arrayTransactions, 400)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYarrayTests500 = tc => {
+  applyRandomTests(tc, arrayTransactions, 500)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYarrayTests600 = tc => {
+  applyRandomTests(tc, arrayTransactions, 600)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYarrayTests1000 = tc => {
+  applyRandomTests(tc, arrayTransactions, 1000)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYarrayTests1800 = tc => {
+  applyRandomTests(tc, arrayTransactions, 1800)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYarrayTests3000 = tc => {
+  t.skip(!t.production)
+  applyRandomTests(tc, arrayTransactions, 3000)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYarrayTests5000 = tc => {
+  t.skip(!t.production)
+  applyRandomTests(tc, arrayTransactions, 5000)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYarrayTests30000 = tc => {
+  t.skip(!t.production)
+  applyRandomTests(tc, arrayTransactions, 30000)
+}

tests/y-map.tests.js

@@ -0,0 +1,680 @@
+import { init, compare, applyRandomTests, Doc } from './testHelper.js' // eslint-disable-line
+
+import {
+  compareIDs
+} from '../src/internals.js'
+
+import * as Y from '../src/index.js'
+import * as t from 'lib0/testing'
+import * as prng from 'lib0/prng'
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testMapHavingIterableAsConstructorParamTests = tc => {
+  const { map0 } = init(tc, { users: 1 })
+
+  const m1 = new Y.Map(Object.entries({ number: 1, string: 'hello' }))
+  map0.set('m1', m1)
+  t.assert(m1.get('number') === 1)
+  t.assert(m1.get('string') === 'hello')
+
+  const m2 = new Y.Map([
+    ['object', { x: 1 }],
+    ['boolean', true]
+  ])
+  map0.set('m2', m2)
+  t.assert(m2.get('object').x === 1)
+  t.assert(m2.get('boolean') === true)
+
+  const m3 = new Y.Map([...m1, ...m2])
+  map0.set('m3', m3)
+  t.assert(m3.get('number') === 1)
+  t.assert(m3.get('string') === 'hello')
+  t.assert(m3.get('object').x === 1)
+  t.assert(m3.get('boolean') === true)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testBasicMapTests = tc => {
+  const { testConnector, users, map0, map1, map2 } = init(tc, { users: 3 })
+  users[2].disconnect()
+
+  map0.set('null', null)
+  map0.set('number', 1)
+  map0.set('string', 'hello Y')
+  map0.set('object', { key: { key2: 'value' } })
+  map0.set('y-map', new Y.Map())
+  map0.set('boolean1', true)
+  map0.set('boolean0', false)
+  const map = map0.get('y-map')
+  map.set('y-array', new Y.Array())
+  const array = map.get('y-array')
+  array.insert(0, [0])
+  array.insert(0, [-1])
+
+  t.assert(map0.get('null') === null, 'client 0 computed the change (null)')
+  t.assert(map0.get('number') === 1, 'client 0 computed the change (number)')
+  t.assert(map0.get('string') === 'hello Y', 'client 0 computed the change (string)')
+  t.assert(map0.get('boolean0') === false, 'client 0 computed the change (boolean)')
+  t.assert(map0.get('boolean1') === true, 'client 0 computed the change (boolean)')
+  t.compare(map0.get('object'), { key: { key2: 'value' } }, 'client 0 computed the change (object)')
+  t.assert(map0.get('y-map').get('y-array').get(0) === -1, 'client 0 computed the change (type)')
+  t.assert(map0.size === 7, 'client 0 map has correct size')
+
+  users[2].connect()
+  testConnector.flushAllMessages()
+
+  t.assert(map1.get('null') === null, 'client 1 received the update (null)')
+  t.assert(map1.get('number') === 1, 'client 1 received the update (number)')
+  t.assert(map1.get('string') === 'hello Y', 'client 1 received the update (string)')
+  t.assert(map1.get('boolean0') === false, 'client 1 computed the change (boolean)')
+  t.assert(map1.get('boolean1') === true, 'client 1 computed the change (boolean)')
+  t.compare(map1.get('object'), { key: { key2: 'value' } }, 'client 1 received the update (object)')
+  t.assert(map1.get('y-map').get('y-array').get(0) === -1, 'client 1 received the update (type)')
+  t.assert(map1.size === 7, 'client 1 map has correct size')
+
+  // compare disconnected user
+  t.assert(map2.get('null') === null, 'client 2 received the update (null) - was disconnected')
+  t.assert(map2.get('number') === 1, 'client 2 received the update (number) - was disconnected')
+  t.assert(map2.get('string') === 'hello Y', 'client 2 received the update (string) - was disconnected')
+  t.assert(map2.get('boolean0') === false, 'client 2 computed the change (boolean)')
+  t.assert(map2.get('boolean1') === true, 'client 2 computed the change (boolean)')
+  t.compare(map2.get('object'), { key: { key2: 'value' } }, 'client 2 received the update (object) - was disconnected')
+  t.assert(map2.get('y-map').get('y-array').get(0) === -1, 'client 2 received the update (type) - was disconnected')
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testGetAndSetOfMapProperty = tc => {
+  const { testConnector, users, map0 } = init(tc, { users: 2 })
+  map0.set('stuff', 'stuffy')
+  map0.set('undefined', undefined)
+  map0.set('null', null)
+  t.compare(map0.get('stuff'), 'stuffy')
+
+  testConnector.flushAllMessages()
+
+  for (const user of users) {
+    const u = user.getMap('map')
+    t.compare(u.get('stuff'), 'stuffy')
+    t.assert(u.get('undefined') === undefined, 'undefined')
+    t.compare(u.get('null'), null, 'null')
+  }
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testYmapSetsYmap = tc => {
+  const { users, map0 } = init(tc, { users: 2 })
+  const map = map0.set('Map', new Y.Map())
+  t.assert(map0.get('Map') === map)
+  map.set('one', 1)
+  t.compare(map.get('one'), 1)
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testYmapSetsYarray = tc => {
+  const { users, map0 } = init(tc, { users: 2 })
+  const array = map0.set('Array', new Y.Array())
+  t.assert(array === map0.get('Array'))
+  array.insert(0, [1, 2, 3])
+  // @ts-ignore
+  t.compare(map0.toJSON(), { Array: [1, 2, 3] })
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testGetAndSetOfMapPropertySyncs = tc => {
+  const { testConnector, users, map0 } = init(tc, { users: 2 })
+  map0.set('stuff', 'stuffy')
+  t.compare(map0.get('stuff'), 'stuffy')
+  testConnector.flushAllMessages()
+  for (const user of users) {
+    const u = user.getMap('map')
+    t.compare(u.get('stuff'), 'stuffy')
+  }
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testGetAndSetOfMapPropertyWithConflict = tc => {
+  const { testConnector, users, map0, map1 } = init(tc, { users: 3 })
+  map0.set('stuff', 'c0')
+  map1.set('stuff', 'c1')
+  testConnector.flushAllMessages()
+  for (const user of users) {
+    const u = user.getMap('map')
+    t.compare(u.get('stuff'), 'c1')
+  }
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testSizeAndDeleteOfMapProperty = tc => {
+  const { map0 } = init(tc, { users: 1 })
+  map0.set('stuff', 'c0')
+  map0.set('otherstuff', 'c1')
+  t.assert(map0.size === 2, `map size is ${map0.size} expected 2`)
+  map0.delete('stuff')
+  t.assert(map0.size === 1, `map size after delete is ${map0.size}, expected 1`)
+  map0.delete('otherstuff')
+  t.assert(map0.size === 0, `map size after delete is ${map0.size}, expected 0`)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testGetAndSetAndDeleteOfMapProperty = tc => {
+  const { testConnector, users, map0, map1 } = init(tc, { users: 3 })
+  map0.set('stuff', 'c0')
+  map1.set('stuff', 'c1')
+  map1.delete('stuff')
+  testConnector.flushAllMessages()
+  for (const user of users) {
+    const u = user.getMap('map')
+    t.assert(u.get('stuff') === undefined)
+  }
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testSetAndClearOfMapProperties = tc => {
+  const { testConnector, users, map0 } = init(tc, { users: 1 })
+  map0.set('stuff', 'c0')
+  map0.set('otherstuff', 'c1')
+  map0.clear()
+  testConnector.flushAllMessages()
+  for (const user of users) {
+    const u = user.getMap('map')
+    t.assert(u.get('stuff') === undefined)
+    t.assert(u.get('otherstuff') === undefined)
+    t.assert(u.size === 0, `map size after clear is ${u.size}, expected 0`)
+  }
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testSetAndClearOfMapPropertiesWithConflicts = tc => {
+  const { testConnector, users, map0, map1, map2, map3 } = init(tc, { users: 4 })
+  map0.set('stuff', 'c0')
+  map1.set('stuff', 'c1')
+  map1.set('stuff', 'c2')
+  map2.set('stuff', 'c3')
+  testConnector.flushAllMessages()
+  map0.set('otherstuff', 'c0')
+  map1.set('otherstuff', 'c1')
+  map2.set('otherstuff', 'c2')
+  map3.set('otherstuff', 'c3')
+  map3.clear()
+  testConnector.flushAllMessages()
+  for (const user of users) {
+    const u = user.getMap('map')
+    t.assert(u.get('stuff') === undefined)
+    t.assert(u.get('otherstuff') === undefined)
+    t.assert(u.size === 0, `map size after clear is ${u.size}, expected 0`)
+  }
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testGetAndSetOfMapPropertyWithThreeConflicts = tc => {
+  const { testConnector, users, map0, map1, map2 } = init(tc, { users: 3 })
+  map0.set('stuff', 'c0')
+  map1.set('stuff', 'c1')
+  map1.set('stuff', 'c2')
+  map2.set('stuff', 'c3')
+  testConnector.flushAllMessages()
+  for (const user of users) {
+    const u = user.getMap('map')
+    t.compare(u.get('stuff'), 'c3')
+  }
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testGetAndSetAndDeleteOfMapPropertyWithThreeConflicts = tc => {
+  const { testConnector, users, map0, map1, map2, map3 } = init(tc, { users: 4 })
+  map0.set('stuff', 'c0')
+  map1.set('stuff', 'c1')
+  map1.set('stuff', 'c2')
+  map2.set('stuff', 'c3')
+  testConnector.flushAllMessages()
+  map0.set('stuff', 'deleteme')
+  map1.set('stuff', 'c1')
+  map2.set('stuff', 'c2')
+  map3.set('stuff', 'c3')
+  map3.delete('stuff')
+  testConnector.flushAllMessages()
+  for (const user of users) {
+    const u = user.getMap('map')
+    t.assert(u.get('stuff') === undefined)
+  }
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testObserveDeepProperties = tc => {
+  const { testConnector, users, map1, map2, map3 } = init(tc, { users: 4 })
+  const _map1 = map1.set('map', new Y.Map())
+  let calls = 0
+  let dmapid
+  map1.observeDeep(events => {
+    events.forEach(event => {
+      calls++
+      // @ts-ignore
+      t.assert(event.keysChanged.has('deepmap'))
+      t.assert(event.path.length === 1)
+      t.assert(event.path[0] === 'map')
+      // @ts-ignore
+      dmapid = event.target.get('deepmap')._item.id
+    })
+  })
+  testConnector.flushAllMessages()
+  const _map3 = map3.get('map')
+  _map3.set('deepmap', new Y.Map())
+  testConnector.flushAllMessages()
+  const _map2 = map2.get('map')
+  _map2.set('deepmap', new Y.Map())
+  testConnector.flushAllMessages()
+  const dmap1 = _map1.get('deepmap')
+  const dmap2 = _map2.get('deepmap')
+  const dmap3 = _map3.get('deepmap')
+  t.assert(calls > 0)
+  t.assert(compareIDs(dmap1._item.id, dmap2._item.id))
+  t.assert(compareIDs(dmap1._item.id, dmap3._item.id))
+  // @ts-ignore we want the possibility of dmapid being undefined
+  t.assert(compareIDs(dmap1._item.id, dmapid))
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testObserversUsingObservedeep = tc => {
+  const { users, map0 } = init(tc, { users: 2 })
+  /**
+   * @type {Array<Array<string|number>>}
+   */
+  const pathes = []
+  let calls = 0
+  map0.observeDeep(events => {
+    events.forEach(event => {
+      pathes.push(event.path)
+    })
+    calls++
+  })
+  map0.set('map', new Y.Map())
+  map0.get('map').set('array', new Y.Array())
+  map0.get('map').get('array').insert(0, ['content'])
+  t.assert(calls === 3)
+  t.compare(pathes, [[], ['map'], ['map', 'array']])
+  compare(users)
+}
+
+// TODO: Test events in Y.Map
+/**
+ * @param {Object<string,any>} is
+ * @param {Object<string,any>} should
+ */
+const compareEvent = (is, should) => {
+  for (const key in should) {
+    t.compare(should[key], is[key])
+  }
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testThrowsAddAndUpdateAndDeleteEvents = tc => {
+  const { users, map0 } = init(tc, { users: 2 })
+  /**
+   * @type {Object<string,any>}
+   */
+  let event = {}
+  map0.observe(e => {
+    event = e // just put it on event, should be thrown synchronously anyway
+  })
+  map0.set('stuff', 4)
+  compareEvent(event, {
+    target: map0,
+    keysChanged: new Set(['stuff'])
+  })
+  // update, oldValue is in contents
+  map0.set('stuff', new Y.Array())
+  compareEvent(event, {
+    target: map0,
+    keysChanged: new Set(['stuff'])
+  })
+  // update, oldValue is in opContents
+  map0.set('stuff', 5)
+  // delete
+  map0.delete('stuff')
+  compareEvent(event, {
+    keysChanged: new Set(['stuff']),
+    target: map0
+  })
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testThrowsDeleteEventsOnClear = tc => {
+  const { users, map0 } = init(tc, { users: 2 })
+  /**
+   * @type {Object<string,any>}
+   */
+  let event = {}
+  map0.observe(e => {
+    event = e // just put it on event, should be thrown synchronously anyway
+  })
+  // set values
+  map0.set('stuff', 4)
+  map0.set('otherstuff', new Y.Array())
+  // clear
+  map0.clear()
+  compareEvent(event, {
+    keysChanged: new Set(['stuff', 'otherstuff']),
+    target: map0
+  })
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testChangeEvent = tc => {
+  const { map0, users } = init(tc, { users: 2 })
+  /**
+   * @type {any}
+   */
+  let changes = null
+  /**
+   * @type {any}
+   */
+  let keyChange = null
+  map0.observe(e => {
+    changes = e.changes
+  })
+  map0.set('a', 1)
+  keyChange = changes.keys.get('a')
+  t.assert(changes !== null && keyChange.action === 'add' && keyChange.oldValue === undefined)
+  map0.set('a', 2)
+  keyChange = changes.keys.get('a')
+  t.assert(changes !== null && keyChange.action === 'update' && keyChange.oldValue === 1)
+  users[0].transact(() => {
+    map0.set('a', 3)
+    map0.set('a', 4)
+  })
+  keyChange = changes.keys.get('a')
+  t.assert(changes !== null && keyChange.action === 'update' && keyChange.oldValue === 2)
+  users[0].transact(() => {
+    map0.set('b', 1)
+    map0.set('b', 2)
+  })
+  keyChange = changes.keys.get('b')
+  t.assert(changes !== null && keyChange.action === 'add' && keyChange.oldValue === undefined)
+  users[0].transact(() => {
+    map0.set('c', 1)
+    map0.delete('c')
+  })
+  t.assert(changes !== null && changes.keys.size === 0)
+  users[0].transact(() => {
+    map0.set('d', 1)
+    map0.set('d', 2)
+  })
+  keyChange = changes.keys.get('d')
+  t.assert(changes !== null && keyChange.action === 'add' && keyChange.oldValue === undefined)
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testYmapEventExceptionsShouldCompleteTransaction = tc => {
+  const doc = new Y.Doc()
+  const map = doc.getMap('map')
+
+  let updateCalled = false
+  let throwingObserverCalled = false
+  let throwingDeepObserverCalled = false
+  doc.on('update', () => {
+    updateCalled = true
+  })
+
+  const throwingObserver = () => {
+    throwingObserverCalled = true
+    throw new Error('Failure')
+  }
+
+  const throwingDeepObserver = () => {
+    throwingDeepObserverCalled = true
+    throw new Error('Failure')
+  }
+
+  map.observe(throwingObserver)
+  map.observeDeep(throwingDeepObserver)
+
+  t.fails(() => {
+    map.set('y', '2')
+  })
+
+  t.assert(updateCalled)
+  t.assert(throwingObserverCalled)
+  t.assert(throwingDeepObserverCalled)
+
+  // check if it works again
+  updateCalled = false
+  throwingObserverCalled = false
+  throwingDeepObserverCalled = false
+  t.fails(() => {
+    map.set('z', '3')
+  })
+
+  t.assert(updateCalled)
+  t.assert(throwingObserverCalled)
+  t.assert(throwingDeepObserverCalled)
+
+  t.assert(map.get('z') === '3')
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testYmapEventHasCorrectValueWhenSettingAPrimitive = tc => {
+  const { users, map0 } = init(tc, { users: 3 })
+  /**
+   * @type {Object<string,any>}
+   */
+  let event = {}
+  map0.observe(e => {
+    event = e
+  })
+  map0.set('stuff', 2)
+  t.compare(event.value, event.target.get(event.name))
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testYmapEventHasCorrectValueWhenSettingAPrimitiveFromOtherUser = tc => {
+  const { users, map0, map1, testConnector } = init(tc, { users: 3 })
+  /**
+   * @type {Object<string,any>}
+   */
+  let event = {}
+  map0.observe(e => {
+    event = e
+  })
+  map1.set('stuff', 2)
+  testConnector.flushAllMessages()
+  t.compare(event.value, event.target.get(event.name))
+  compare(users)
+}
+
+/**
+ * @type {Array<function(Doc,prng.PRNG):void>}
+ */
+const mapTransactions = [
+  function set (user, gen) {
+    const key = prng.oneOf(gen, ['one', 'two'])
+    const value = prng.utf16String(gen)
+    user.getMap('map').set(key, value)
+  },
+  function setType (user, gen) {
+    const key = prng.oneOf(gen, ['one', 'two'])
+    const type = prng.oneOf(gen, [new Y.Array(), new Y.Map()])
+    user.getMap('map').set(key, type)
+    if (type instanceof Y.Array) {
+      type.insert(0, [1, 2, 3, 4])
+    } else {
+      type.set('deepkey', 'deepvalue')
+    }
+  },
+  function _delete (user, gen) {
+    const key = prng.oneOf(gen, ['one', 'two'])
+    user.getMap('map').delete(key)
+  }
+]
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYmapTests10 = tc => {
+  applyRandomTests(tc, mapTransactions, 3)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYmapTests40 = tc => {
+  applyRandomTests(tc, mapTransactions, 40)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYmapTests42 = tc => {
+  applyRandomTests(tc, mapTransactions, 42)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYmapTests43 = tc => {
+  applyRandomTests(tc, mapTransactions, 43)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYmapTests44 = tc => {
+  applyRandomTests(tc, mapTransactions, 44)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYmapTests45 = tc => {
+  applyRandomTests(tc, mapTransactions, 45)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYmapTests46 = tc => {
+  applyRandomTests(tc, mapTransactions, 46)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYmapTests300 = tc => {
+  applyRandomTests(tc, mapTransactions, 300)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYmapTests400 = tc => {
+  applyRandomTests(tc, mapTransactions, 400)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYmapTests500 = tc => {
+  applyRandomTests(tc, mapTransactions, 500)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYmapTests600 = tc => {
+  applyRandomTests(tc, mapTransactions, 600)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYmapTests1000 = tc => {
+  applyRandomTests(tc, mapTransactions, 1000)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYmapTests1800 = tc => {
+  applyRandomTests(tc, mapTransactions, 1800)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYmapTests5000 = tc => {
+  t.skip(!t.production)
+  applyRandomTests(tc, mapTransactions, 5000)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYmapTests10000 = tc => {
+  t.skip(!t.production)
+  applyRandomTests(tc, mapTransactions, 10000)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYmapTests100000 = tc => {
+  t.skip(!t.production)
+  applyRandomTests(tc, mapTransactions, 100000)
+}

tests/y-text.tests.js

@@ -0,0 +1,846 @@
+import * as Y from './testHelper.js'
+import * as t from 'lib0/testing'
+import * as prng from 'lib0/prng'
+import * as math from 'lib0/math'
+
+const { init, compare } = Y
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testDeltaAfterConcurrentFormatting = tc => {
+  const { text0, text1, testConnector } = init(tc, { users: 2 })
+  text0.insert(0, 'abcde')
+  testConnector.flushAllMessages()
+  text0.format(0, 3, { bold: true })
+  text1.format(2, 2, { bold: true })
+  let delta = null
+  text1.observe(event => {
+    delta = event.delta
+  })
+  testConnector.flushAllMessages()
+  t.compare(delta, [])
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testBasicInsertAndDelete = tc => {
+  const { users, text0 } = init(tc, { users: 2 })
+  let delta
+
+  text0.observe(event => {
+    delta = event.delta
+  })
+
+  text0.delete(0, 0)
+  t.assert(true, 'Does not throw when deleting zero elements with position 0')
+
+  text0.insert(0, 'abc')
+  t.assert(text0.toString() === 'abc', 'Basic insert works')
+  t.compare(delta, [{ insert: 'abc' }])
+
+  text0.delete(0, 1)
+  t.assert(text0.toString() === 'bc', 'Basic delete works (position 0)')
+  t.compare(delta, [{ delete: 1 }])
+
+  text0.delete(1, 1)
+  t.assert(text0.toString() === 'b', 'Basic delete works (position 1)')
+  t.compare(delta, [{ retain: 1 }, { delete: 1 }])
+
+  users[0].transact(() => {
+    text0.insert(0, '1')
+    text0.delete(0, 1)
+  })
+  t.compare(delta, [])
+
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testBasicFormat = tc => {
+  const { users, text0 } = init(tc, { users: 2 })
+  let delta
+  text0.observe(event => {
+    delta = event.delta
+  })
+  text0.insert(0, 'abc', { bold: true })
+  t.assert(text0.toString() === 'abc', 'Basic insert with attributes works')
+  t.compare(text0.toDelta(), [{ insert: 'abc', attributes: { bold: true } }])
+  t.compare(delta, [{ insert: 'abc', attributes: { bold: true } }])
+  text0.delete(0, 1)
+  t.assert(text0.toString() === 'bc', 'Basic delete on formatted works (position 0)')
+  t.compare(text0.toDelta(), [{ insert: 'bc', attributes: { bold: true } }])
+  t.compare(delta, [{ delete: 1 }])
+  text0.delete(1, 1)
+  t.assert(text0.toString() === 'b', 'Basic delete works (position 1)')
+  t.compare(text0.toDelta(), [{ insert: 'b', attributes: { bold: true } }])
+  t.compare(delta, [{ retain: 1 }, { delete: 1 }])
+  text0.insert(0, 'z', { bold: true })
+  t.assert(text0.toString() === 'zb')
+  t.compare(text0.toDelta(), [{ insert: 'zb', attributes: { bold: true } }])
+  t.compare(delta, [{ insert: 'z', attributes: { bold: true } }])
+  // @ts-ignore
+  t.assert(text0._start.right.right.right.content.str === 'b', 'Does not insert duplicate attribute marker')
+  text0.insert(0, 'y')
+  t.assert(text0.toString() === 'yzb')
+  t.compare(text0.toDelta(), [{ insert: 'y' }, { insert: 'zb', attributes: { bold: true } }])
+  t.compare(delta, [{ insert: 'y' }])
+  text0.format(0, 2, { bold: null })
+  t.assert(text0.toString() === 'yzb')
+  t.compare(text0.toDelta(), [{ insert: 'yz' }, { insert: 'b', attributes: { bold: true } }])
+  t.compare(delta, [{ retain: 1 }, { retain: 1, attributes: { bold: null } }])
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testMultilineFormat = tc => {
+  const ydoc = new Y.Doc()
+  const testText = ydoc.getText('test')
+  testText.insert(0, 'Test\nMulti-line\nFormatting')
+  testText.applyDelta([
+    { retain: 4, attributes: { bold: true } },
+    { retain: 1 }, // newline character
+    { retain: 10, attributes: { bold: true } },
+    { retain: 1 }, // newline character
+    { retain: 10, attributes: { bold: true } }
+  ])
+  t.compare(testText.toDelta(), [
+    { insert: 'Test', attributes: { bold: true } },
+    { insert: '\n' },
+    { insert: 'Multi-line', attributes: { bold: true } },
+    { insert: '\n' },
+    { insert: 'Formatting', attributes: { bold: true } }
+  ])
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testNotMergeEmptyLinesFormat = tc => {
+  const ydoc = new Y.Doc()
+  const testText = ydoc.getText('test')
+  testText.applyDelta([
+    { insert: 'Text' },
+    { insert: '\n', attributes: { title: true } },
+    { insert: '\nText' },
+    { insert: '\n', attributes: { title: true } }
+  ])
+  t.compare(testText.toDelta(), [
+    { insert: 'Text' },
+    { insert: '\n', attributes: { title: true } },
+    { insert: '\nText' },
+    { insert: '\n', attributes: { title: true } }
+  ])
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testGetDeltaWithEmbeds = tc => {
+  const { text0 } = init(tc, { users: 1 })
+  text0.applyDelta([{
+    insert: { linebreak: 's' }
+  }])
+  t.compare(text0.toDelta(), [{
+    insert: { linebreak: 's' }
+  }])
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testTypesAsEmbed = tc => {
+  const { text0, text1, testConnector } = init(tc, { users: 2 })
+  text0.applyDelta([{
+    insert: new Y.Map([['key', 'val']])
+  }])
+  t.compare(text0.toDelta()[0].insert.toJSON(), { key: 'val' })
+  let firedEvent = false
+  text1.observe(event => {
+    const d = event.delta
+    t.assert(d.length === 1)
+    t.compare(d.map(x => /** @type {Y.AbstractType<any>} */ (x.insert).toJSON()), [{ key: 'val' }])
+    firedEvent = true
+  })
+  testConnector.flushAllMessages()
+  const delta = text1.toDelta()
+  t.assert(delta.length === 1)
+  t.compare(delta[0].insert.toJSON(), { key: 'val' })
+  t.assert(firedEvent, 'fired the event observer containing a Type-Embed')
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testSnapshot = tc => {
+  const { text0 } = init(tc, { users: 1 })
+  const doc0 = /** @type {Y.Doc} */ (text0.doc)
+  doc0.gc = false
+  text0.applyDelta([{
+    insert: 'abcd'
+  }])
+  const snapshot1 = Y.snapshot(doc0)
+  text0.applyDelta([{
+    retain: 1
+  }, {
+    insert: 'x'
+  }, {
+    delete: 1
+  }])
+  const snapshot2 = Y.snapshot(doc0)
+  text0.applyDelta([{
+    retain: 2
+  }, {
+    delete: 3
+  }, {
+    insert: 'x'
+  }, {
+    delete: 1
+  }])
+  const state1 = text0.toDelta(snapshot1)
+  t.compare(state1, [{ insert: 'abcd' }])
+  const state2 = text0.toDelta(snapshot2)
+  t.compare(state2, [{ insert: 'axcd' }])
+  const state2Diff = text0.toDelta(snapshot2, snapshot1)
+  // @ts-ignore Remove userid info
+  state2Diff.forEach(v => {
+    if (v.attributes && v.attributes.ychange) {
+      delete v.attributes.ychange.user
+    }
+  })
+  t.compare(state2Diff, [{ insert: 'a' }, { insert: 'x', attributes: { ychange: { type: 'added' } } }, { insert: 'b', attributes: { ychange: { type: 'removed' } } }, { insert: 'cd' }])
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testSnapshotDeleteAfter = tc => {
+  const { text0 } = init(tc, { users: 1 })
+  const doc0 = /** @type {Y.Doc} */ (text0.doc)
+  doc0.gc = false
+  text0.applyDelta([{
+    insert: 'abcd'
+  }])
+  const snapshot1 = Y.snapshot(doc0)
+  text0.applyDelta([{
+    retain: 4
+  }, {
+    insert: 'e'
+  }])
+  const state1 = text0.toDelta(snapshot1)
+  t.compare(state1, [{ insert: 'abcd' }])
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testToJson = tc => {
+  const { text0 } = init(tc, { users: 1 })
+  text0.insert(0, 'abc', { bold: true })
+  t.assert(text0.toJSON() === 'abc', 'toJSON returns the unformatted text')
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testToDeltaEmbedAttributes = tc => {
+  const { text0 } = init(tc, { users: 1 })
+  text0.insert(0, 'ab', { bold: true })
+  text0.insertEmbed(1, { image: 'imageSrc.png' }, { width: 100 })
+  const delta0 = text0.toDelta()
+  t.compare(delta0, [{ insert: 'a', attributes: { bold: true } }, { insert: { image: 'imageSrc.png' }, attributes: { width: 100 } }, { insert: 'b', attributes: { bold: true } }])
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testToDeltaEmbedNoAttributes = tc => {
+  const { text0 } = init(tc, { users: 1 })
+  text0.insert(0, 'ab', { bold: true })
+  text0.insertEmbed(1, { image: 'imageSrc.png' })
+  const delta0 = text0.toDelta()
+  t.compare(delta0, [{ insert: 'a', attributes: { bold: true } }, { insert: { image: 'imageSrc.png' } }, { insert: 'b', attributes: { bold: true } }], 'toDelta does not set attributes key when no attributes are present')
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testFormattingRemoved = tc => {
+  const { text0 } = init(tc, { users: 1 })
+  text0.insert(0, 'ab', { bold: true })
+  text0.delete(0, 2)
+  t.assert(Y.getTypeChildren(text0).length === 1)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testFormattingRemovedInMidText = tc => {
+  const { text0 } = init(tc, { users: 1 })
+  text0.insert(0, '1234')
+  text0.insert(2, 'ab', { bold: true })
+  text0.delete(2, 2)
+  t.assert(Y.getTypeChildren(text0).length === 3)
+}
+
+/**
+ * Reported in https://github.com/yjs/yjs/issues/344
+ *
+ * @param {t.TestCase} tc
+ */
+export const testFormattingDeltaUnnecessaryAttributeChange = tc => {
+  const { text0, text1, testConnector } = init(tc, { users: 2 })
+  text0.insert(0, '\n', {
+    PARAGRAPH_STYLES: 'normal',
+    LIST_STYLES: 'bullet'
+  })
+  text0.insert(1, 'abc', {
+    PARAGRAPH_STYLES: 'normal'
+  })
+  testConnector.flushAllMessages()
+  /**
+   * @type {Array<any>}
+   */
+  const deltas = []
+  text0.observe(event => {
+    deltas.push(event.delta)
+  })
+  text1.observe(event => {
+    deltas.push(event.delta)
+  })
+  text1.format(0, 1, { LIST_STYLES: 'number' })
+  testConnector.flushAllMessages()
+  const filteredDeltas = deltas.filter(d => d.length > 0)
+  t.assert(filteredDeltas.length === 2)
+  t.compare(filteredDeltas[0], [
+    { retain: 1, attributes: { LIST_STYLES: 'number' } }
+  ])
+  t.compare(filteredDeltas[0], filteredDeltas[1])
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testInsertAndDeleteAtRandomPositions = tc => {
+  // @todo optimize to run at least as fast as previous marker approach
+  const N = 100000
+  const { text0 } = init(tc, { users: 1 })
+  const gen = tc.prng
+
+  // create initial content
+  // let expectedResult = init
+  text0.insert(0, prng.word(gen, N / 2, N / 2))
+
+  // apply changes
+  for (let i = 0; i < N; i++) {
+    const pos = prng.uint32(gen, 0, text0.length)
+    if (prng.bool(gen)) {
+      const len = prng.uint32(gen, 1, 5)
+      const word = prng.word(gen, 0, len)
+      text0.insert(pos, word)
+      // expectedResult = expectedResult.slice(0, pos) + word + expectedResult.slice(pos)
+    } else {
+      const len = prng.uint32(gen, 0, math.min(3, text0.length - pos))
+      text0.delete(pos, len)
+      // expectedResult = expectedResult.slice(0, pos) + expectedResult.slice(pos + len)
+    }
+  }
+  // t.compareStrings(text0.toString(), expectedResult)
+  t.describe('final length', '' + text0.length)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testAppendChars = tc => {
+  const N = 10000
+  const { text0 } = init(tc, { users: 1 })
+
+  // apply changes
+  for (let i = 0; i < N; i++) {
+    text0.insert(text0.length, 'a')
+  }
+  t.assert(text0.length === N)
+}
+
+const largeDocumentSize = 100000
+
+const id = Y.createID(0, 0)
+const c = new Y.ContentString('a')
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testBestCase = tc => {
+  const N = largeDocumentSize
+  const items = new Array(N)
+  t.measureTime('time to create two million items in the best case', () => {
+    const parent = /** @type {any} */ ({})
+    let prevItem = null
+    for (let i = 0; i < N; i++) {
+      /**
+       * @type {Y.Item}
+       */
+      const n = new Y.Item(Y.createID(0, 0), null, null, null, null, null, null, c)
+      // items.push(n)
+      items[i] = n
+      n.right = prevItem
+      n.rightOrigin = prevItem ? id : null
+      n.content = c
+      n.parent = parent
+      prevItem = n
+    }
+  })
+  const newArray = new Array(N)
+  t.measureTime('time to copy two million items to new Array', () => {
+    for (let i = 0; i < N; i++) {
+      newArray[i] = items[i]
+    }
+  })
+}
+
+const tryGc = () => {
+  // @ts-ignore
+  if (typeof global !== 'undefined' && global.gc) {
+    // @ts-ignore
+    global.gc()
+  }
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testLargeFragmentedDocument = tc => {
+  const itemsToInsert = largeDocumentSize
+  let update = /** @type {any} */ (null)
+  ;(() => {
+    const doc1 = new Y.Doc()
+    const text0 = doc1.getText('txt')
+    tryGc()
+    t.measureTime(`time to insert ${itemsToInsert} items`, () => {
+      doc1.transact(() => {
+        for (let i = 0; i < itemsToInsert; i++) {
+          text0.insert(0, '0')
+        }
+      })
+    })
+    tryGc()
+    t.measureTime('time to encode document', () => {
+      update = Y.encodeStateAsUpdateV2(doc1)
+    })
+    t.describe('Document size:', update.byteLength)
+  })()
+  ;(() => {
+    const doc2 = new Y.Doc()
+    tryGc()
+    t.measureTime(`time to apply ${itemsToInsert} updates`, () => {
+      Y.applyUpdateV2(doc2, update)
+    })
+  })()
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testIncrementalUpdatesPerformanceOnLargeFragmentedDocument = tc => {
+  const itemsToInsert = largeDocumentSize
+  const updates = /** @type {Array<Uint8Array>} */ ([])
+  ;(() => {
+    const doc1 = new Y.Doc()
+    doc1.on('update', update => {
+      updates.push(update)
+    })
+    const text0 = doc1.getText('txt')
+    tryGc()
+    t.measureTime(`time to insert ${itemsToInsert} items`, () => {
+      doc1.transact(() => {
+        for (let i = 0; i < itemsToInsert; i++) {
+          text0.insert(0, '0')
+        }
+      })
+    })
+    tryGc()
+  })()
+  ;(() => {
+    t.measureTime(`time to merge ${itemsToInsert} updates (differential updates)`, () => {
+      Y.mergeUpdates(updates)
+    })
+    tryGc()
+    t.measureTime(`time to merge ${itemsToInsert} updates (ydoc updates)`, () => {
+      const ydoc = new Y.Doc()
+      updates.forEach(update => {
+        Y.applyUpdate(ydoc, update)
+      })
+    })
+  })()
+}
+
+/**
+ * Splitting surrogates can lead to invalid encoded documents.
+ *
+ * https://github.com/yjs/yjs/issues/248
+ *
+ * @param {t.TestCase} tc
+ */
+export const testSplitSurrogateCharacter = tc => {
+  {
+    const { users, text0 } = init(tc, { users: 2 })
+    users[1].disconnect() // disconnecting forces the user to encode the split surrogate
+    text0.insert(0, '👾') // insert surrogate character
+    // split surrogate, which should not lead to an encoding error
+    text0.insert(1, 'hi!')
+    compare(users)
+  }
+  {
+    const { users, text0 } = init(tc, { users: 2 })
+    users[1].disconnect() // disconnecting forces the user to encode the split surrogate
+    text0.insert(0, '👾👾') // insert surrogate character
+    // partially delete surrogate
+    text0.delete(1, 2)
+    compare(users)
+  }
+  {
+    const { users, text0 } = init(tc, { users: 2 })
+    users[1].disconnect() // disconnecting forces the user to encode the split surrogate
+    text0.insert(0, '👾👾') // insert surrogate character
+    // formatting will also split surrogates
+    text0.format(1, 2, { bold: true })
+    compare(users)
+  }
+}
+
+/**
+ * Search marker bug https://github.com/yjs/yjs/issues/307
+ *
+ * @param {t.TestCase} tc
+ */
+export const testSearchMarkerBug1 = tc => {
+  const { users, text0, text1, testConnector } = init(tc, { users: 2 })
+
+  users[0].on('update', update => {
+    users[0].transact(() => {
+      Y.applyUpdate(users[0], update)
+    })
+  })
+  users[0].on('update', update => {
+    users[1].transact(() => {
+      Y.applyUpdate(users[1], update)
+    })
+  })
+
+  text0.insert(0, 'a_a')
+  testConnector.flushAllMessages()
+  text0.insert(2, 's')
+  testConnector.flushAllMessages()
+  text1.insert(3, 'd')
+  testConnector.flushAllMessages()
+  text0.delete(0, 5)
+  testConnector.flushAllMessages()
+  text0.insert(0, 'a_a')
+  testConnector.flushAllMessages()
+  text0.insert(2, 's')
+  testConnector.flushAllMessages()
+  text1.insert(3, 'd')
+  testConnector.flushAllMessages()
+  t.compareStrings(text0.toString(), text1.toString())
+  t.compareStrings(text0.toString(), 'a_sda')
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testFormattingBug = async tc => {
+  const ydoc1 = new Y.Doc()
+  const ydoc2 = new Y.Doc()
+  const text1 = ydoc1.getText()
+  text1.insert(0, '\n\n\n')
+  text1.format(0, 3, { url: 'http://example.com' })
+  ydoc1.getText().format(1, 1, { url: 'http://docs.yjs.dev' })
+  Y.applyUpdate(ydoc2, Y.encodeStateAsUpdate(ydoc1))
+  const text2 = ydoc2.getText()
+  const expectedResult = [
+    { insert: '\n', attributes: { url: 'http://example.com' } },
+    { insert: '\n', attributes: { url: 'http://docs.yjs.dev' } },
+    { insert: '\n', attributes: { url: 'http://example.com' } }
+  ]
+  t.compare(text1.toDelta(), expectedResult)
+  t.compare(text1.toDelta(), text2.toDelta())
+  console.log(text1.toDelta())
+}
+
+// RANDOM TESTS
+
+let charCounter = 0
+
+/**
+ * Random tests for pure text operations without formatting.
+ *
+ * @type Array<function(any,prng.PRNG):void>
+ */
+const textChanges = [
+  /**
+   * @param {Y.Doc} y
+   * @param {prng.PRNG} gen
+   */
+  (y, gen) => { // insert text
+    const ytext = y.getText('text')
+    const insertPos = prng.int32(gen, 0, ytext.length)
+    const text = charCounter++ + prng.word(gen)
+    const prevText = ytext.toString()
+    ytext.insert(insertPos, text)
+    t.compareStrings(ytext.toString(), prevText.slice(0, insertPos) + text + prevText.slice(insertPos))
+  },
+  /**
+   * @param {Y.Doc} y
+   * @param {prng.PRNG} gen
+   */
+  (y, gen) => { // delete text
+    const ytext = y.getText('text')
+    const contentLen = ytext.toString().length
+    const insertPos = prng.int32(gen, 0, contentLen)
+    const overwrite = math.min(prng.int32(gen, 0, contentLen - insertPos), 2)
+    const prevText = ytext.toString()
+    ytext.delete(insertPos, overwrite)
+    t.compareStrings(ytext.toString(), prevText.slice(0, insertPos) + prevText.slice(insertPos + overwrite))
+  }
+]
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGenerateTextChanges5 = tc => {
+  const { users } = checkResult(Y.applyRandomTests(tc, textChanges, 5))
+  const cleanups = Y.cleanupYTextFormatting(users[0].getText('text'))
+  t.assert(cleanups === 0)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGenerateTextChanges30 = tc => {
+  const { users } = checkResult(Y.applyRandomTests(tc, textChanges, 30))
+  const cleanups = Y.cleanupYTextFormatting(users[0].getText('text'))
+  t.assert(cleanups === 0)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGenerateTextChanges40 = tc => {
+  const { users } = checkResult(Y.applyRandomTests(tc, textChanges, 40))
+  const cleanups = Y.cleanupYTextFormatting(users[0].getText('text'))
+  t.assert(cleanups === 0)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGenerateTextChanges50 = tc => {
+  const { users } = checkResult(Y.applyRandomTests(tc, textChanges, 50))
+  const cleanups = Y.cleanupYTextFormatting(users[0].getText('text'))
+  t.assert(cleanups === 0)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGenerateTextChanges70 = tc => {
+  const { users } = checkResult(Y.applyRandomTests(tc, textChanges, 70))
+  const cleanups = Y.cleanupYTextFormatting(users[0].getText('text'))
+  t.assert(cleanups === 0)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGenerateTextChanges90 = tc => {
+  const { users } = checkResult(Y.applyRandomTests(tc, textChanges, 90))
+  const cleanups = Y.cleanupYTextFormatting(users[0].getText('text'))
+  t.assert(cleanups === 0)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGenerateTextChanges300 = tc => {
+  const { users } = checkResult(Y.applyRandomTests(tc, textChanges, 300))
+  const cleanups = Y.cleanupYTextFormatting(users[0].getText('text'))
+  t.assert(cleanups === 0)
+}
+
+const marks = [
+  { bold: true },
+  { italic: true },
+  { italic: true, color: '#888' }
+]
+
+const marksChoices = [
+  undefined,
+  ...marks
+]
+
+/**
+ * Random tests for all features of y-text (formatting, embeds, ..).
+ *
+ * @type Array<function(any,prng.PRNG):void>
+ */
+const qChanges = [
+  /**
+   * @param {Y.Doc} y
+   * @param {prng.PRNG} gen
+   */
+  (y, gen) => { // insert text
+    const ytext = y.getText('text')
+    const insertPos = prng.int32(gen, 0, ytext.length)
+    const attrs = prng.oneOf(gen, marksChoices)
+    const text = charCounter++ + prng.word(gen)
+    ytext.insert(insertPos, text, attrs)
+  },
+  /**
+   * @param {Y.Doc} y
+   * @param {prng.PRNG} gen
+   */
+  (y, gen) => { // insert embed
+    const ytext = y.getText('text')
+    const insertPos = prng.int32(gen, 0, ytext.length)
+    if (prng.bool(gen)) {
+      ytext.insertEmbed(insertPos, { image: 'https://user-images.githubusercontent.com/5553757/48975307-61efb100-f06d-11e8-9177-ee895e5916e5.png' })
+    } else {
+      ytext.insertEmbed(insertPos, new Y.Map([[prng.word(gen), prng.word(gen)]]))
+    }
+  },
+  /**
+   * @param {Y.Doc} y
+   * @param {prng.PRNG} gen
+   */
+  (y, gen) => { // delete text
+    const ytext = y.getText('text')
+    const contentLen = ytext.toString().length
+    const insertPos = prng.int32(gen, 0, contentLen)
+    const overwrite = math.min(prng.int32(gen, 0, contentLen - insertPos), 2)
+    ytext.delete(insertPos, overwrite)
+  },
+  /**
+   * @param {Y.Doc} y
+   * @param {prng.PRNG} gen
+   */
+  (y, gen) => { // format text
+    const ytext = y.getText('text')
+    const contentLen = ytext.toString().length
+    const insertPos = prng.int32(gen, 0, contentLen)
+    const overwrite = math.min(prng.int32(gen, 0, contentLen - insertPos), 2)
+    const format = prng.oneOf(gen, marks)
+    ytext.format(insertPos, overwrite, format)
+  },
+  /**
+   * @param {Y.Doc} y
+   * @param {prng.PRNG} gen
+   */
+  (y, gen) => { // insert codeblock
+    const ytext = y.getText('text')
+    const insertPos = prng.int32(gen, 0, ytext.toString().length)
+    const text = charCounter++ + prng.word(gen)
+    const ops = []
+    if (insertPos > 0) {
+      ops.push({ retain: insertPos })
+    }
+    ops.push({ insert: text }, { insert: '\n', format: { 'code-block': true } })
+    ytext.applyDelta(ops)
+  }
+]
+
+/**
+ * @param {any} result
+ */
+const checkResult = result => {
+  for (let i = 1; i < result.testObjects.length; i++) {
+    /**
+     * @param {any} d
+     */
+    const typeToObject = d => d.insert instanceof Y.AbstractType ? d.insert.toJSON() : d
+    const p1 = result.users[i].getText('text').toDelta().map(typeToObject)
+    const p2 = result.users[i].getText('text').toDelta().map(typeToObject)
+    t.compare(p1, p2)
+  }
+  // Uncomment this to find formatting-cleanup issues
+  // const cleanups = Y.cleanupYTextFormatting(result.users[0].getText('text'))
+  // t.assert(cleanups === 0)
+  return result
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGenerateQuillChanges1 = tc => {
+  const { users } = checkResult(Y.applyRandomTests(tc, qChanges, 1))
+  const cleanups = Y.cleanupYTextFormatting(users[0].getText('text'))
+  t.assert(cleanups === 0)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGenerateQuillChanges2 = tc => {
+  const { users } = checkResult(Y.applyRandomTests(tc, qChanges, 2))
+  const cleanups = Y.cleanupYTextFormatting(users[0].getText('text'))
+  t.assert(cleanups === 0)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGenerateQuillChanges2Repeat = tc => {
+  for (let i = 0; i < 1000; i++) {
+    const { users } = checkResult(Y.applyRandomTests(tc, qChanges, 2))
+    const cleanups = Y.cleanupYTextFormatting(users[0].getText('text'))
+    t.assert(cleanups === 0)
+  }
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGenerateQuillChanges3 = tc => {
+  checkResult(Y.applyRandomTests(tc, qChanges, 3))
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGenerateQuillChanges30 = tc => {
+  checkResult(Y.applyRandomTests(tc, qChanges, 30))
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGenerateQuillChanges40 = tc => {
+  checkResult(Y.applyRandomTests(tc, qChanges, 40))
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGenerateQuillChanges70 = tc => {
+  checkResult(Y.applyRandomTests(tc, qChanges, 70))
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGenerateQuillChanges100 = tc => {
+  checkResult(Y.applyRandomTests(tc, qChanges, 100))
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGenerateQuillChanges300 = tc => {
+  checkResult(Y.applyRandomTests(tc, qChanges, 300))
+}

tests/y-xml.tests.js

@@ -0,0 +1,185 @@
+import { init, compare } from './testHelper.js'
+import * as Y from '../src/index.js'
+
+import * as t from 'lib0/testing'
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testSetProperty = tc => {
+  const { testConnector, users, xml0, xml1 } = init(tc, { users: 2 })
+  xml0.setAttribute('height', '10')
+  t.assert(xml0.getAttribute('height') === '10', 'Simple set+get works')
+  testConnector.flushAllMessages()
+  t.assert(xml1.getAttribute('height') === '10', 'Simple set+get works (remote)')
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testHasProperty = tc => {
+  const { testConnector, users, xml0, xml1 } = init(tc, { users: 2 })
+  xml0.setAttribute('height', '10')
+  t.assert(xml0.hasAttribute('height'), 'Simple set+has works')
+  testConnector.flushAllMessages()
+  t.assert(xml1.hasAttribute('height'), 'Simple set+has works (remote)')
+
+  xml0.removeAttribute('height')
+  t.assert(!xml0.hasAttribute('height'), 'Simple set+remove+has works')
+  testConnector.flushAllMessages()
+  t.assert(!xml1.hasAttribute('height'), 'Simple set+remove+has works (remote)')
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testEvents = tc => {
+  const { testConnector, users, xml0, xml1 } = init(tc, { users: 2 })
+  /**
+   * @type {any}
+   */
+  let event
+  /**
+   * @type {any}
+   */
+  let remoteEvent
+  xml0.observe(e => {
+    event = e
+  })
+  xml1.observe(e => {
+    remoteEvent = e
+  })
+  xml0.setAttribute('key', 'value')
+  t.assert(event.attributesChanged.has('key'), 'YXmlEvent.attributesChanged on updated key')
+  testConnector.flushAllMessages()
+  t.assert(remoteEvent.attributesChanged.has('key'), 'YXmlEvent.attributesChanged on updated key (remote)')
+  // check attributeRemoved
+  xml0.removeAttribute('key')
+  t.assert(event.attributesChanged.has('key'), 'YXmlEvent.attributesChanged on removed attribute')
+  testConnector.flushAllMessages()
+  t.assert(remoteEvent.attributesChanged.has('key'), 'YXmlEvent.attributesChanged on removed attribute (remote)')
+  xml0.insert(0, [new Y.XmlText('some text')])
+  t.assert(event.childListChanged, 'YXmlEvent.childListChanged on inserted element')
+  testConnector.flushAllMessages()
+  t.assert(remoteEvent.childListChanged, 'YXmlEvent.childListChanged on inserted element (remote)')
+  // test childRemoved
+  xml0.delete(0)
+  t.assert(event.childListChanged, 'YXmlEvent.childListChanged on deleted element')
+  testConnector.flushAllMessages()
+  t.assert(remoteEvent.childListChanged, 'YXmlEvent.childListChanged on deleted element (remote)')
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testTreewalker = tc => {
+  const { users, xml0 } = init(tc, { users: 3 })
+  const paragraph1 = new Y.XmlElement('p')
+  const paragraph2 = new Y.XmlElement('p')
+  const text1 = new Y.XmlText('init')
+  const text2 = new Y.XmlText('text')
+  paragraph1.insert(0, [text1, text2])
+  xml0.insert(0, [paragraph1, paragraph2, new Y.XmlElement('img')])
+  const allParagraphs = xml0.querySelectorAll('p')
+  t.assert(allParagraphs.length === 2, 'found exactly two paragraphs')
+  t.assert(allParagraphs[0] === paragraph1, 'querySelectorAll found paragraph1')
+  t.assert(allParagraphs[1] === paragraph2, 'querySelectorAll found paragraph2')
+  t.assert(xml0.querySelector('p') === paragraph1, 'querySelector found paragraph1')
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testYtextAttributes = tc => {
+  const ydoc = new Y.Doc()
+  const ytext = /** @type {Y.XmlText} */ (ydoc.get('', Y.XmlText))
+  ytext.observe(event => {
+    t.compare(event.changes.keys.get('test'), { action: 'add', oldValue: undefined })
+  })
+  ytext.setAttribute('test', 42)
+  t.compare(ytext.getAttribute('test'), 42)
+  t.compare(ytext.getAttributes(), { test: 42 })
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testSiblings = tc => {
+  const ydoc = new Y.Doc()
+  const yxml = ydoc.getXmlFragment()
+  const first = new Y.XmlText()
+  const second = new Y.XmlElement('p')
+  yxml.insert(0, [first, second])
+  t.assert(first.nextSibling === second)
+  t.assert(second.prevSibling === first)
+  t.assert(first.parent === yxml)
+  t.assert(yxml.parent === null)
+  t.assert(yxml.firstChild === first)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testInsertafter = tc => {
+  const ydoc = new Y.Doc()
+  const yxml = ydoc.getXmlFragment()
+  const first = new Y.XmlText()
+  const second = new Y.XmlElement('p')
+  const third = new Y.XmlElement('p')
+
+  const deepsecond1 = new Y.XmlElement('span')
+  const deepsecond2 = new Y.XmlText()
+  second.insertAfter(null, [deepsecond1])
+  second.insertAfter(deepsecond1, [deepsecond2])
+
+  yxml.insertAfter(null, [first, second])
+  yxml.insertAfter(second, [third])
+
+  t.assert(yxml.length === 3)
+  t.assert(second.get(0) === deepsecond1)
+  t.assert(second.get(1) === deepsecond2)
+
+  t.compareArrays(yxml.toArray(), [first, second, third])
+
+  t.fails(() => {
+    const el = new Y.XmlElement('p')
+    el.insertAfter(deepsecond1, [new Y.XmlText()])
+  })
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testClone = tc => {
+  const ydoc = new Y.Doc()
+  const yxml = ydoc.getXmlFragment()
+  const first = new Y.XmlText('text')
+  const second = new Y.XmlElement('p')
+  const third = new Y.XmlElement('p')
+  yxml.push([first, second, third])
+  t.compareArrays(yxml.toArray(), [first, second, third])
+
+  const cloneYxml = yxml.clone()
+  ydoc.getArray('copyarr').insert(0, [cloneYxml])
+  t.assert(cloneYxml.length === 3)
+  t.compare(cloneYxml.toJSON(), yxml.toJSON())
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testFormattingBug = tc => {
+  const ydoc = new Y.Doc()
+  const yxml = /** @type {Y.XmlText} */ (ydoc.get('', Y.XmlText))
+  const delta = [
+    { insert: 'A', attributes: { em: {}, strong: {} } },
+    { insert: 'B', attributes: { em: {} } },
+    { insert: 'C', attributes: { em: {}, strong: {} } }
+  ]
+  yxml.applyDelta(delta)
+  t.compare(yxml.toDelta(), delta)
+}

tsconfig.json

@@ -0,0 +1,64 @@
+{
+  "compilerOptions": {
+    /* Basic Options */
+    "target": "es2018",
+    "lib": ["es2018", "dom"],                             /* Specify library files to be included in the compilation. */
+    "allowJs": true,                       /* Allow javascript files to be compiled. */
+    "checkJs": true,                       /* Report errors in .js files. */
+    // "jsx": "preserve",                     /* Specify JSX code generation: 'preserve', 'react-native', or 'react'. */
+    "declaration": true,                   /* Generates corresponding '.d.ts' file. */
+    // "declarationMap": true,                /* Generates a sourcemap for each corresponding '.d.ts' file. */
+    // "sourceMap": true,                     /* Generates corresponding '.map' file. */
+    // "outFile": "./dist/yjs.js",                       /* Concatenate and emit output to single file. */
+    "outDir": "./dist",                        /* Redirect output structure to the directory. */
+    "rootDir": "./",                       /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
+    // "composite": true,                     /* Enable project compilation */
+    // "removeComments": true,                /* Do not emit comments to output. */
+    // "noEmit": true,                        /* Do not emit outputs. */
+    // "importHelpers": true,                 /* Import emit helpers from 'tslib'. */
+    // "downlevelIteration": true,            /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */
+    // "isolatedModules": true,               /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */
+
+    /* Strict Type-Checking Options */
+    "strict": true,                           /* Enable all strict type-checking options. */
+    "noImplicitAny": true,                 /* Raise error on expressions and declarations with an implied 'any' type. */
+    "emitDeclarationOnly": true,
+    // "strictNullChecks": true,              /* Enable strict null checks. */
+    // "strictFunctionTypes": true,           /* Enable strict checking of function types. */
+    // "strictPropertyInitialization": true,  /* Enable strict checking of property initialization in classes. */
+    // "noImplicitThis": true,                /* Raise error on 'this' expressions with an implied 'any' type. */
+    // "alwaysStrict": true,                  /* Parse in strict mode and emit "use strict" for each source file. */
+
+    /* Additional Checks */
+    // "noUnusedLocals": true,                /* Report errors on unused locals. */
+    // "noUnusedParameters": true,            /* Report errors on unused parameters. */
+    // "noImplicitReturns": true,             /* Report error when not all code paths in function return a value. */
+    // "noFallthroughCasesInSwitch": true,    /* Report errors for fallthrough cases in switch statement. */
+
+    /* Module Resolution Options */
+    "moduleResolution": "node",            /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */
+    "baseUrl": "./",                       /* Base directory to resolve non-absolute module names. */
+    "paths": {
+      "yjs": ["./src/index.js"]
+    },                           /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */
+    // "rootDirs": [],                        /* List of root folders whose combined content represents the structure of the project at runtime. */
+    // "typeRoots": [],                       /* List of folders to include type definitions from. */
+    // "types": [],                           /* Type declaration files to be included in compilation. */
+    // "allowSyntheticDefaultImports": true,  /* Allow default imports from modules with no default export. This does not affect code emit, just typechecking. */
+    "esModuleInterop": true,                   /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
+    // "preserveSymlinks": true,              /* Do not resolve the real path of symlinks. */
+
+    /* Source Map Options */
+    // "sourceRoot": "",                      /* Specify the location where debugger should locate TypeScript files instead of source locations. */
+    // "mapRoot": "",                         /* Specify the location where debugger should locate map files instead of generated locations. */
+    // "inlineSourceMap": true,               /* Emit a single file with source maps instead of having a separate file. */
+    // "inlineSources": true,                 /* Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set. */
+
+    /* Experimental Options */
+    // "experimentalDecorators": true,        /* Enables experimental support for ES7 decorators. */
+    // "emitDecoratorMetadata": true,         /* Enables experimental support for emitting type metadata for decorators. */
+    // "maxNodeModuleJsDepth": 0,
+    // "types": ["./src/utils/typedefs.js"]
+  },
+  "include": ["./src/**/*.js", "./tests/**/*.js"]
+}