change parameter order of transaction events

implement offset parameter in Ref.toStruct

.flowconfig

@@ -1,12 +0,0 @@
-[ignore]
-.*/node_modules/.*
-.*/dist/.*
-.*/build/.*
-
-[include]
-./src/
-
-[libs]
-./declarations/
-
-[options]

.gitignore

@@ -1,15 +1,4 @@
 node_modules
-bower_components
-build
-build_test
-.directory
-.codio
-.settings
-.jshintignore
-.jshintrc
-.validate.json
-/y.js
-/y.js.map
-/y-*
+dist
 .vscode
-jsconfig.json
+docs

.gitmodules

@@ -1,4 +0,0 @@
-[submodule "dist"]
-	path = dist
-	url = https://github.com/y-js/yjs.git
-	branch = dist

.jsdoc.json

@@ -0,0 +1,50 @@
+{
+  "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": {
+      "y-js.org": "yjs.website"
+    },
+    "logo": {
+      "url": "https://user-images.githubusercontent.com/5553757/48975307-61efb100-f06d-11e8-9177-ee895e5916e5.png",
+      "width": "162px",
+      "height": "162px",
+      "link": "/"
+    },
+    "tabNames": {
+      "api": "API",
+      "tutorials": "Examples"
+    },
+    "footerText": "Shared Editing",
+    "css": [
+      "./style.css"
+    ],
+    "default": {
+      "staticFiles": {
+          "include": ["examples/"]
+      }
+    }
+  },
+  "opts": {
+    "destination": "./docs/",
+    "encoding": "utf8",
+    "private": false,
+    "recurse": true,
+    "template": "./node_modules/tui-jsdoc-template",
+    "tutorials": "./examples"
+  }
+}

README.md

@@ -1,5 +1,5 @@
 
-# ![Yjs](http://y-js.org/images/yjs.png)
+# ![Yjs](https://user-images.githubusercontent.com/5553757/48975307-61efb100-f06d-11e8-9177-ee895e5916e5.png)
 
 Yjs is a framework for offline-first p2p shared editing on structured data like
 text, richtext, json, or XML. It is fairly easy to get started, as Yjs hides
@@ -64,6 +64,18 @@ missing modules.
 <script src="./bower_components/yjs/y.js"></script>
 ```
 
+### CDN
+```
+<script src="https://cdn.jsdelivr.net/npm/yjs@12/dist/y.js"></script>
+<script src="https://cdn.jsdelivr.net/npm/y-array@10/dist/y-array.js"></script>
+<script src="https://cdn.jsdelivr.net/npm/y-websockets-client@8/dist/y-websockets-client.js"></script>
+<script src="https://cdn.jsdelivr.net/npm/y-memory@8/dist/y-memory.js"></script>
+<script src="https://cdn.jsdelivr.net/npm/y-map@10/dist/y-map.js"></script>
+<script src="https://cdn.jsdelivr.net/npm/y-text@9/dist/y-text.js"></script>
+// ..
+// do the same for all modules you want to use
+```
+
 ### Npm
 ```
 npm install --save yjs % add all y-* modules you want to use
@@ -76,7 +88,6 @@ var Y = require('yjs')
 require('y-array')(Y) // add the y-array type to Yjs
 require('y-websockets-client')(Y)
 require('y-memory')(Y)
-require('y-array')(Y)
 require('y-map')(Y)
 require('y-text')(Y)
 // ..
@@ -89,7 +100,6 @@ import Y from 'yjs'
 import yArray from 'y-array'
 import yWebsocketsClient from 'y-webrtc'
 import yMemory from 'y-memory'
-import yArray from 'y-array'
 import yMap from 'y-map'
 import yText from 'y-text'
 // ..
@@ -121,7 +131,7 @@ Here is a simple example of a shared textarea
             // name: 'xmpp'
             room: 'my-room' // clients connecting to the same room share data
           },
-          sourceDir: '/bower_components', // location of the y-* modules (browser only)
+          sourceDir: './bower_components', // location of the y-* modules (browser only)
           share: {
             textarea: 'Text' // y.share.textarea is of type y-text
           }
@@ -238,7 +248,7 @@ The promise returns an instance of Y. We denote it with a lower case `y`.
   * y-websockets-client aways waits to sync with the server
 * y.connector.disconnect()
   * Force to disconnect this instance from the other instances
-* y.connector.reconnect()
+* y.connector.connect()
   * Try to reconnect to the other instances (needs to be supported by the
     connector)
   * Not supported by y-xmpp

README.v13.md

@@ -0,0 +1,370 @@
+# ![Yjs](https://user-images.githubusercontent.com/5553757/48975307-61efb100-f06d-11e8-9177-ee895e5916e5.png)
+> The shared editing library
+
+Yjs is a library for automatic conflict resolution on shared state. It implements an operation-based CRDT and exposes its internal CRDT model as shared types. Shared types are common data types like `Map` or `Array` with superpowers - changes are automatically distributed to other peers and merged without merge conflicts.
+
+Yjs is **network agnostic** (p2p!), supports many existing **rich text editors**, **offline editing**, **version snapshots**, **shared cursors**, and encodes update messages using **binary protocol encoding**. 
+
+* Chat: [https://gitter.im/y-js/yjs](https://gitter.im/y-js/yjs)
+* Demos: [https://yjs.website/tutorial-prosemirror.html](https://yjs.website/tutorial-prosemirror.html)
+* API Docs: [https://yjs.website/](https://yjs.website/)
+
+### Supported Editors:
+
+| Name                                                   | Cursors | Binding |  Demo |
+|---|:-:|---|---|
+| [ProseMirror](https://prosemirror.net/) | ✔ | [y-prosemirror](http://github.com/y-js/y-prosemirror) | [link](https://yjs.website/tutorial-prosemirror.html) |
+| [Quill](https://quilljs.com/) |  | [y-quill](http://github.com/y-js/y-quill) | [link](https://yjs.website/tutorial-quill.html) |
+| [CodeMirror](https://codemirror.net/) | ✔ | [y-codemirror](http://github.com/y-js/y-codemirror) | [link](https://yjs.website/tutorial-codemirror.html) |
+| [Ace](https://ace.c9.io/) | | [y-ace](http://github.com/y-js/y-ace) | [link]() |
+| [Monaco](https://microsoft.github.io/monaco-editor/) | | [y-monaco](http://github.com/y-js/y-monaco) | [link]() |
+
+### Providers
+
+Setting up the communication between clients, managing awareness information, and storing shared data for offline usage is quite a hassle. *Providers* manage all that for you and are a good off-the-shelf solution
+
+* [y-websockets](http://github.com/y-js/y-websockets)
+* [y-webrtc](http://github.com/y-js/y-webrtc)
+* [y-dat](http://github.com/y-js/y-dat)
+
+
+### Shared Types
+
+# Table of Contents
+
+* [Getting Started](#Getting-Started)
+  * [Tutorial](#Short-Tutorial)
+* [Providers](#Providers)
+  * [Websocket](#Websocket)
+  * [Ydb](#Ydb)
+  * [Create a Custom Provider](#Create-a-Custom-Provider)
+* [Shared Types](#Shared-Types)
+  * [YArray](#Yarray)
+  * [YMap](#YMap)
+  * [YText](#YText)
+  * [YXmlFragment and YXmlElement](#YXmlFragment-and-YXmlElement)
+  * [Create a Custom Type](#Create-a-Custom-Type)
+* [Bindings](#Bindings)
+  * [PromeMirror](#ProseMirror)
+  * [Quill](#Quill)
+  * [CodeMirror](#CodeMirror)
+  * [Ace](#Ace)
+  * [Monaco](#Monace)
+  * [DOM](#DOM)
+  * [Textarea](#Textarea)
+  * [Create a Custom Binding](#Create-a-Custom-Binding)
+* [Transaction](#Transaction)
+* [Offline Editing](#Offline-Editing)
+* [Awareness](#Awareness)
+* [Working with Yjs](#Working-with-Yjs)
+  * [Typescript Declarations](#Typescript-Declarations)
+* [Binary Protocols](#Binary-Protocols)
+  * [Sync Protocol](#Sync-Protocols)
+  * [Awareness Protocol](#Awareness-Protocols)
+  * [Auth Protocol](#Auth-Protocol)
+* [Yjs CRDT Algorithm](#Yjs-CRDT-Algorithm)
+* [Evaluation](#Evaluation)
+  * [Existing shared editing libraries](#Exisisting-Javascript-Products)
+  * [CRDT Algorithms](#CRDT-Algorithms)
+  * [Comparison of CRDT with OT](#Comparing-CRDT-with-OT)
+  * [Comparison of CRDT Algorithms](#Comparing-CRDT-Algorithms)
+  * [Comparison of Yjs with other Implementations](#Comparing-Yjs-with-other-Implementations)
+* [License and Author](#License-and-Author)
+
+## Getting Started
+
+Yjs does not hava any dependencies. Install this package with your favorite package manager, or just copy the files into your project.
+
+```sh
+npm i yjs
+```
+
+##### Quickstart
+
+Yjs itself only knows how to do conflict resolution. You need to choose a provider, that handles how document updates are distributed over the network.
+
+We will start by running a websocket server (part of the [websocket provider](#Websocket-Provider)):
+
+```sh
+PORT=1234 node ./node_modules/yjs/provider/websocket/server.js
+```
+
+The following client-side code connects to the websocket server and opens a shared document.
+
+```js
+import * as Y from 'yjs'
+import { WebsocketProvider } from 'yjs/provider/websocket.js'
+
+const provider = new WebsocketProvider('http://localhost:1234')
+const sharedDocument = provider.get('my-favourites')
+```
+
+All content created in a shared document is shared among all peers that request the same document. Now we define types on the shared document:
+
+```js
+sharedDocument.define('movie-ratings', Y.Map)
+sharedDocument.define('favourite-food', Y.Array)
+```
+
+All clients that define `'movie-ratings'` as `Y.Map` on the shared document named `'my-favourites'` have access to the same shared type. Example:
+
+**Client 1:**
+
+```js
+sharedDocument.define('movie-ratings', Y.Map)
+sharedDocument.define('favourite-food', Y.Array)
+
+const movies = sharedDocument.get('movie-ratings')
+const food = sharedDocument.get('fovourite-food')
+
+movies.set('deadpool', 10)
+food.insert(0, ['burger'])
+```
+
+**Client 2:**
+
+```js
+sharedDocument.define('movie-ratings', Y.Map)
+sharedDocument.define('favourite-food', Y.Map) // <- note that this definition differs from client1
+
+const movies = sharedDocument.get('movie-ratings')
+const food = sharedDocument.get('fovourite-food')
+
+movies.set('yt rewind', -10)
+food.set('pancake', 10)
+
+// after some time, when client1 and client2 synced, the movie list will be merged:
+movies.toJSON() // => { 'deadpool': 10, 'yt rewind': -10 }
+
+// But since client1 and client2 defined the types differently,
+// they do not have access to each others food list.
+food.toJSON() // => { pancake: 10 }
+```
+
+Now you understand how types are defined on a shared document. Next you can jump to one of the [tutorials on our website](https://yjs.website/tutorial-prosemirror.html) or continue reading about [Providers](#Providers), [Shared Types](#Shared-Types), and [Bindings](#Bindings).
+
+## API
+
+## Providers
+
+In Yjs, a provider handles the communication channel to *authenticate*, *authorize*, and *exchange document updates*. Yjs ships with some existing providers. 
+
+### Websocket Provider
+
+The websocket provider implements a classical client server model. Clients connect to a single endpoint over websocket. The server distributes awareness information and document updates among clients.
+
+The Websocket Provider is a solid choice if you want a central source that handles authentication and authorization. Websockets also send header information and cookies, so you can use existing authentication mechanisms with this server. I recommend that you slightly adapt the server in `./provider/websocket/server.js` to your needs.
+
+* Supports cross-tab communication. When you open the same document in the same browser, changes on the document are exchanged via cross-tab communication ([Broadcast Channel](https://developer.mozilla.org/en-US/docs/Web/API/Broadcast_Channel_API) and [localStorage](https://developer.mozilla.org/en-US/docs/Web/API/Window/localStorage) as fallback).
+* Supports exange of awareness information (e.g. cursors)
+
+##### Start a Websocket Server:
+
+```sh
+PORT=1234 node ./node_modules/yjs/provider/websocket/server.js
+```
+
+**Websocket Server with Persistence**
+
+Persist document updates in a LevelDB database.
+
+See [LevelDB Persistence](#LevelDB Persistence) for more info.
+
+```sh
+PORT=1234 YPERSISTENCE=./dbDir node ./node_modules/yjs/provider/websocket/server.js
+```
+
+##### Client Code:
+
+```js
+import * as Y from 'yjs'
+import { WebsocketProvider } from 'yjs/provider/websocket.js'
+
+const provider = new WebsocketProvider('http://localhost:1234')
+
+// open a websocket connection to http://localhost:1234/my-document-name
+const sharedDocument = provider.get('my-document-name')
+
+sharedDocument.on('status', event => {
+  console.log(event.status) // logs "connected" or "disconnected"
+})
+```
+
+#### Scaling
+
+These are mere suggestions how you could scale your server environment.
+
+**Option 1:** Websocket servers communicate with each other via a PubSub server. A room is represented by a PubSub channel. The downside of this approach is that the same shared document may be handled by many servers. But the upside is that this approach is fault tolerant, does not have a single point of failure, and is perfectly fit for route balancing.
+
+**Option 2:** Sharding with *consistent hashing*. Each document is handled by a unique server. This patterns requires an entity, like etcd, that performs regular health checks and manages servers. Based on the list of available servers (which is managed by etcd) a proxy calculates which server is responsible for each requested document. The disadvantage of this approach is that it is that load distribution may not be fair. Still, this approach may be the preferred solution if you want to store the shared document in a database - e.g. for indexing.
+
+### Ydb Provider
+
+TODO
+
+### Create Custom Provider
+
+A provider is only a concept. I encourage you to implement the same provider interface found above. This makes it easy to exchange communication protocols.
+
+Since providers handle the communication channel, they will necessarily interact with the [binary protocols](#Binary-Protocols). I suggest that you build upon the existing protocols. But you may also implement a custom communication protocol.
+
+Read section [Sync Protocol](#Sync-Protocol) to learn how syncing works.
+
+## Shared Types
+
+A shared type is just a normal data type like [Map](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map) or [Array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array). But a shared type may also be modified by a remote client. Conflicts are automatically resolved by the rules described in this section - but please note that this is only a rough overview of how conflict resolution works. Please read the [Yjs CRDT Algorithm](#Yjs-CRDT-Algorithm) section for an in-depth description of the conflict resolution approach.
+
+As explained in [Tutorial](#Tutorial), a shared type is shared among all peers when they are defined with the same name on the same shared document. I.e.
+
+```js
+sharedDocument.define('my-array', Y.Array)
+
+const myArray = sharedDocument.get('my-array')
+```
+
+You may define a shared types several times, as long as you don't change the type definition.
+
+```js
+sharedDocument.define('my-array', Y.Array)
+
+const myArray = sharedDocument.get('my-array')
+
+const alsoMyArray = sharedDocument.define('my-array', Y.Array)
+
+console.log(myArray === alsoMyArray) // => true
+```
+
+All shared types have an `type.observe(event => ..)` method that allows you to observe any changes. You may also observe all changes on a type and any of its children with the `type.observeDeep(events => ..)` method. Here, `events` is the [Set](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set) of events that were fired on type, or any of its children.
+
+All Events inherit from [YEvent](https://yjs.website/module-utils.YEvent.html).
+
+### YMap
+> Complete API docs: [https://yjs.website/module-types.ymap](https://yjs.website/module-types.ymap)
+
+The YMap type is very similar to the JavaScript [Map](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map). 
+
+YMap fires [YMapEvents](https://yjs.website/module-types.YMapEvent.html).
+
+```js
+import * as Y from 'yjs'
+
+const ymap = new Y.Map()
+
+ymap.observe(event => {
+  console.log('ymap keys changed:', event.keysChanged, event.remote)
+})
+
+ymap.set('key', 'value') // => ymap keys changed: Set{ 'key' } false
+ymap.delete('key') // => ymap keys changed: Set{ 'key' }
+
+const ymap2 = new YMap()
+ymap2.set(1, 'two')
+
+ymap.set('type', ymap2) // => ymap keys changed: Set{ 'type' }
+```
+
+##### Concurrent YMap changes
+
+* Concurrent edits on different keys do not affect each other. E.g. if client1 does `ymap.set('a', 1)` and client2 does `ymap.set('b', 2)`, both clients will end up with `YMap{ a: 1, b: 2 }`
+* If client1 and client2 `set` the same property at the same time, the edit from the client with the smaller userID will prevail (`sharedDocument.userID`)
+* If client1 sets a property `ymap.set('a', 1)` and client2 deletes a property `ymap.delete('a')`, the set operation always prevails.
+
+### YArray
+> Complete API docs: [https://yjs.website/module-types.yarray](https://yjs.website/module-types.yarray)
+
+YArray fires [YArrayEvents](https://yjs.website/module-types.YMapEvent.html).
+
+
+```js
+import * as Y from 'yjs'
+
+const yarray = new Y.Array()
+
+yarray.observe(event => {
+  console.log('yarray changed:', event.addedElements, event.removedElements, event.remote)
+})
+
+// insert two elements at position 0
+yarray.insert(0, ['a', 1]) // => yarray changed: Set{Item{'a'}, Item{1}}, Set{}, false 
+console.log(yarray.toArray()) // => ['a', 1]
+yarray.delete(1, 1) // yarray changed: Set{}, Set{Item{1}}, false
+
+yarray.insert(1, new Y.Map()) // => yarray changed: Set{YMap{}}, Set{}, false
+
+// The difference between .toArray and .toJSON:
+console.log(yarray.toArray()) // => ['a', YMap{}]
+console.log(yarray.toJSON()) // => ['a', {}]
+```
+
+As you can see from the above example, primitive data is wrapped into an Item. This makes it possible to find the exact location of the change.
+
+##### Concurrent YArray changes
+
+* YArray internally represents the data as a doubly linked list. The Array `['a', YMap{}, 1]` is internally represented as `Item{'a'} <-> YMap{} <-> Item{1}`. Accordingly, the insert operation `yarray.insert(1, ['b'])` is internally transformed to `insert Item{'b'} between Item{'a'} and YMap{}`.
+* When an Item is deleted, it is only marked as deleted. Only its content is garbage collected and freed from memory.
+* Therefore, the remote operation `insert x between a and b` can still be fulfilled when item `a` or item `b` are deleted.
+* In case that two clients insert content between the same items (a concurrent insertion), the order of the insertions is decided based on the `sharedDocument.userID`.
+
+### YText
+> Complete API docs: [https://yjs.website/module-types.ytext](https://yjs.website/module-types.ytext)
+
+A YText is basically a [YArray](#YArray) that is optimized for text content. 
+
+### YXmlFragment and YXmlElement
+> Complete API docs: [https://yjs.website/module-types.yxmlfragment](https://yjs.website/module-types.yxmlfragment) and [https://yjs.website/module-types.yxmlelement](https://yjs.website/module-types.yxmlelement)
+
+### Custom Types
+
+## Bindings
+
+## Transaction
+
+
+
+## Binary Protocols
+
+### Sync Protocol
+
+Sync steps
+
+### Awareness Protocol
+
+### Auth Protocol
+
+## Offline Editing
+
+It is trivial with Yjs to persist the local state to indexeddb, so it is always available when working offline. But there are two non-trivial questions that need to answered when implementing a professional offline editing app:
+
+1. How does a client sync down all rooms that were modified while offline?
+2. How does a client sync up all rooms that were modified while offline?
+
+Assuming 5000 documents are stored on each client for offline usage. How do we sync up/down each of those documents after a client comes online? It would be inefficient to sync each of those rooms separately. The only provider that currently supports syncing many rooms efficiently is Ydb, because its database layer is optimized to sync many rooms with each client.
+
+If you do not care about 1. and 2. you can use `/persistences/indexeddb.js` to mirror the local state to indexeddb.
+
+## Working with Yjs
+
+### Typescript Declarations
+
+Until [this](https://github.com/Microsoft/TypeScript/issues/7546) is fixed, the only way to get type declarations is by adding Yjs to the list of checked files:
+
+```json
+{
+  "compilerOptions": {
+    "allowJs": true,
+    "checkJs": true,
+    ..
+  },
+  "maxNodeModuleJsDepth": 5
+}
+```
+
+## CRDT Algorithm
+
+## License and Author
+
+Yjs and all related projects are [**MIT licensed**](./LICENSE). Some files also contain an additional copyright notice that allows you to copy and modify the code without shipping the copyright notice (e.g. `./provider/websocket/WebsocketProvider.js` and `./provider/websocket/server.js`)
+
+Yjs is based on the research I did as a student at the RWTH i5. I am working on Yjs in my spare time. Please help me by donating or hiring me for consulting, so I can continue to work on this project.
+
+kevin.jahns@protonmail.com

declarations/Structs.js

@@ -1,72 +0,0 @@
-/* @flow */
-
-type UserId = string
-type Id = [UserId, number|string]
-
-/*
-type Struct = {
-  id: Id,
-  left?: Id,
-  right?: Id,
-  target?: Id,
-  struct: 'Insert' | 'Delete'
-}*/
-
-type Struct = Insertion | Deletion
-type Operation = Struct
-
-type Insertion = {
-  id: Id,
-  left: ?Id,
-  origin: ?Id,
-  right: ?Id,
-  parent: Id,
-  parentSub: ?Id,
-  opContent: ?Id,
-  content: ?any,
-  struct: 'Insert'
-}
-
-type Deletion = {
-  target: Id,
-  struct: 'Delete'
-}
-
-type MapStruct = {
-  id: Id,
-  type: TypeNames,
-  map: any
-}
-
-type ListStruct = {
-  id: Id,
-  type: TypeNames,
-  start: Id,
-  end: Id
-}
-
-
-type MessageSyncStep1 = {
-  type: 'sync step 1',
-  deleteSet: any,
-  stateSet: any
-}
-
-type MessageSyncStep2 = {
-  type: 'sync step 2',
-  os: Array<Operation>,
-  deleteSet: any,
-  stateSet: any
-}
-
-type MessageUpdate = {
-  type: 'update',
-  ops: Array<Operation>
-}
-
-type MessageSyncDone = {
-  type: 'sync done'
-}
-
-type Message = MessageSyncStep1 | MessageSyncStep2 | MessageUpdate | MessageSyncDone
-

declarations/Y.js

@@ -1,34 +0,0 @@
-/* @flow */
-
-type YGlobal = {
-	utils: Object,
-	Struct: any,
-	AbstractDatabase: any,
-	AbstractConnector: any,
-	Transaction: any
-}
-
-type YConfig = {
-	db: Object,
-	connector: Object,
-	root: Object
-}
-
-type TypeName = 'array' | 'map' | 'text'
-
-declare var YConcurrency_TestingMode : boolean
-
-type Transaction<A> = Generator<any, A, any>
-
-type SyncRole = 'master' | 'slave'
-
-declare class Store {
-	find: (id:Id) => Transaction<any>;
-	put: (n:any) => Transaction<void>;
-	delete: (id:Id) => Transaction<void>;
-	findWithLowerBound: (start:Id) => Transaction<any>;
-	findWithUpperBound: (end:Id) => Transaction<any>;
-	findNext: (id:Id) => Transaction<any>;
-	findPrev: (id:Id) => Transaction<any>;
-	iterate: (t:any,start:?Id,end:?Id,gen:any) => Transaction<any>;
-}

examples/.gitignore

@@ -0,0 +1 @@
+build

examples/codemirror.html

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+<!DOCTYPE html>
+<html>
+<head>
+    <title>Yjs CodeMirror Example</title>
+    <link rel=stylesheet href="https://codemirror.net/lib/codemirror.css">
+    <style>
+      #container {
+        border: grey;
+        border-style: solid;
+        border-width: thin;
+      }
+    </style>
+  </head>
+<body>
+  <p>This example shows how to bind a YText type to <a href="https://codemirror.net/">CodeMirror</a> editor.</p>
+  <p>The content of this editor is shared with every client who visits this domain.</p>
+  <div class="code-html">
+<style>
+.remote-caret {
+  position: absolute;
+  border-left: black;
+  border-left-style: solid;
+  border-left-width: 2px;
+  height: 1em;
+}
+.remote-caret > div {
+  position: relative;
+  top: -1.05em;
+  font-size: 13px;
+  background-color: rgb(250, 129, 0);
+  font-family: serif;
+  font-style: normal;
+  font-weight: normal;
+  line-height: normal;
+  user-select: none;
+  color: white;
+  padding-left: 2px;
+  padding-right: 2px;
+}
+</style>
+<div id="container"></div>
+  </div>
+  <!-- The actual source file for the following code is found in ./codemirror.js. Run `npm run watch` to compile the files -->
+  <script class="code-js" src="./build/codemirror.js" type="module">
+import * as Y from 'yjs'
+import { WebsocketProvider } from 'yjs/provider/websocket.js'
+import { CodeMirrorBinding } from 'yjs/bindings/codemirror.js'
+
+import * as conf from './exampleConfig.js'
+
+import CodeMirror from 'codemirror'
+import 'codemirror/mode/javascript/javascript.js'
+
+const provider = new WebsocketProvider(conf.serverAddress)
+const ydocument = provider.get('codemirror')
+const ytext = ydocument.define('codemirror', Y.Text)
+
+const editor = new CodeMirror(document.querySelector('#container'), {
+    mode: 'javascript',
+    lineNumbers: true
+})
+
+const binding = new CodeMirrorBinding(ytext, editor)
+
+window.codemirrorExample = {
+  binding, editor, ytext, ydocument
+}
+  </script>
+</body>
+</html>

examples/codemirror.js

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+import { WebsocketProvider } from 'y-websocket'
+import { CodeMirrorBinding } from 'y-codemirror'
+
+import * as conf from './exampleConfig.js'
+
+import CodeMirror from 'codemirror'
+import 'codemirror/mode/javascript/javascript.js'
+
+const provider = new WebsocketProvider(conf.serverAddress)
+const ydocument = provider.get('codemirror')
+const ytext = ydocument.getText('codemirror')
+
+const editor = new CodeMirror(document.querySelector('#container'), {
+  mode: 'javascript',
+  lineNumbers: true
+})
+
+const binding = new CodeMirrorBinding(ytext, editor)
+
+window.codemirrorExample = {
+  binding, editor, ytext, ydocument
+}

examples/dom.html

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+<!DOCTYPE html>
+<html>
+<head>
+    <title>Yjs Prosemirror Example</title>
+    <link rel=stylesheet href="https://prosemirror.net/css/editor.css">
+    <style>
+      #content {
+        min-height: 500px;
+      }
+    </style>
+</head>
+<body>
+  <p>This example shows how to bind a YXmlFragment type to an arbitrary DOM element. We set the DOM element to contenteditable so it basically behaves like a very powerful rich-text editor.</p>
+  <p>The content of this editor is shared with every client who visits this domain.</p>
+  <hr>
+  <div class="code-html">
+
+<div id="content" contenteditable=""></div>
+  </div>
+  <!-- The actual source file for the following code is found in ./dom.js. Run `npm run watch` to compile the files -->
+  <script class="code-js" src="./build/dom.js" type="module">
+    import * as Y from 'yjs/index.js'
+    import { WebsocketProvider } from 'yjs/provider/websocket.js'
+    import { DomBinding } from 'yjs/bindings/dom.js'
+    import * as conf from './exampleConfig.js'
+
+    const provider = new WebsocketProvider(conf.serverAddress)
+    const ydocument = provider.get('dom')
+    const type = ydocument.define('xml', Y.XmlFragment)
+    const binding = new DomBinding(type, document.querySelector('#content'), { scrollingElement: document.scrollingElement })
+
+    window.example = {
+      provider, ydocument, type, binding
+    }
+  </script>
+</body>
+</html>

examples/dom.js

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+import * as Y from '../src/index.js'
+import { WebsocketProvider } from 'y-websocket'
+import { DomBinding } from 'y-dom'
+import * as conf from './exampleConfig.js'
+
+const provider = new WebsocketProvider(conf.serverAddress)
+const ydocument = provider.get('dom')
+const type = ydocument.define('xml', Y.XmlFragment)
+const binding = new DomBinding(type, document.querySelector('#content'), { scrollingElement: document.scrollingElement })
+
+window.example = {
+  provider, ydocument, type, binding
+}

examples/exampleConfig.js

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+/* eslint-env browser */
+
+const isDeployed = location.hostname === 'yjs.website'
+
+if (!isDeployed) {
+  console.log('%cYjs: Start your local websocket server by running %c`npm run websocket-server`', 'color:blue', 'color: grey; font-weight: bold')
+}
+
+export const serverAddress = isDeployed ? 'wss://api.yjs.website' : 'ws://localhost:1234'

examples/examples.json

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+{
+  "codemirror": {
+    "title": "CodeMirror Binding"
+  },
+  "prosemirror": {
+    "title": "ProseMirror Binding"
+  },
+  "textarea": {
+    "title": "Textarea Binding"
+  },
+  "quill": {
+    "title": "Quill Binding"
+  },
+  "dom": {
+    "title": "Dom Binding"
+  }
+}

examples/prosemirror-history.js

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+
+import { Plugin } from 'prosemirror-state'
+import crel from 'crel'
+import * as Y from '../src/index.js'
+import { prosemirrorPluginKey } from 'y-prosemirror'
+import * as encoding from 'lib0/encoding.js'
+import * as decoding from 'lib0/decoding.js'
+import * as historyProtocol from 'y-protocols/history.js'
+
+const niceColors = ['#3cb44b', '#4363d8', '#f58231', '#911eb4', '#46f0f0', '#f032e6', '#bcf60c', '#008080', '#9a6324', '#800000', '#808000', '#000075', '#808080']
+
+const createUserCSS = (userid, username, color = 'rgb(250, 129, 0)', color2 = 'rgba(250, 129, 0, .41)') => `
+  [ychange_state][ychange_user="${userid}"]:hover::before {
+    content: "${username}" !important;
+    background-color: ${color} !important;
+  }
+  [ychange_state="added"][ychange_user="${userid}"] {
+    background-color: ${color2} !important;
+  }
+  [ychange_state="removed"][ychange_user="${userid}"] {
+    color: ${color} !important;
+  }
+`
+
+export const noteHistoryPlugin = new Plugin({
+  state: {
+    init (initargs, state) {
+      return new NoteHistoryPlugin()
+    },
+    apply (tr, pluginState) {
+      return pluginState
+    }
+  },
+  view (editorView) {
+    const hstate = noteHistoryPlugin.getState(editorView.state)
+    hstate.init(editorView)
+    return {
+      destroy: hstate.destroy.bind(hstate)
+    }
+  }
+})
+
+const createWrapper = () => {
+  const wrapper = crel('div', { style: 'display: flex;' })
+  const historyContainer = crel('div', { style: 'align-self: baseline; flex-basis: 250px;', class: 'shared-history' })
+  wrapper.insertBefore(historyContainer, null)
+  const userStyleContainer = crel('style')
+  wrapper.insertBefore(userStyleContainer, null)
+  return { wrapper, historyContainer, userStyleContainer }
+}
+
+class NoteHistoryPlugin {
+  init (editorView) {
+    this.editorView = editorView
+    const { historyContainer, wrapper, userStyleContainer } = createWrapper()
+    this.userStyleContainer = userStyleContainer
+    this.wrapper = wrapper
+    this.historyContainer = historyContainer
+    const n = editorView.dom.parentNode.parentNode
+    n.parentNode.replaceChild(this.wrapper, n)
+    n.style['flex-grow'] = '1'
+    wrapper.insertBefore(n, this.wrapper.firstChild)
+    this.render()
+    const y = prosemirrorPluginKey.getState(this.editorView.state).y
+    const history = y.define('history', Y.Array)
+    history.observe(this.render.bind(this))
+  }
+  destroy () {
+    this.wrapper.parentNode.replaceChild(this.wrapper.firstChild, this.wrapper)
+    const y = prosemirrorPluginKey.getState(this.editorView.state).y
+    const history = y.define('history', Y.Array)
+    history.unobserve(this.render)
+  }
+  render () {
+    const y = prosemirrorPluginKey.getState(this.editorView.state).y
+    const history = y.define('history', Y.Array).toArray()
+    const fragment = document.createDocumentFragment()
+    const snapshotBtn = crel('button', { type: 'button' }, ['snapshot'])
+    fragment.insertBefore(snapshotBtn, null)
+    let _prevSnap = null // empty
+    snapshotBtn.addEventListener('click', () => {
+      const awareness = y.getAwarenessInfo()
+      const userMap = new Map()
+      const aw = y.getLocalAwarenessInfo()
+      userMap.set(y.userID, aw.name || 'unknown')
+      awareness.forEach((a, userID) => {
+        userMap.set(userID, a.name || 'Unknown')
+      })
+      this.snapshot(userMap)
+    })
+    history.forEach(buf => {
+      const decoder = decoding.createDecoder(buf)
+      const snapshot = historyProtocol.readHistorySnapshot(decoder)
+      const date = new Date(decoding.readUint32(decoder) * 1000)
+      const restoreBtn = crel('button', { type: 'button' }, ['restore'])
+      const a = crel('a', [
+        '• ' + date.toUTCString(), restoreBtn
+      ])
+      const el = crel('div', [ a ])
+      let prevSnapshot = _prevSnap // rebind to new variable
+      restoreBtn.addEventListener('click', event => {
+        if (prevSnapshot === null) {
+          prevSnapshot = { ds: snapshot.ds, sm: new Map() }
+        }
+        this.editorView.dispatch(this.editorView.state.tr.setMeta(prosemirrorPluginKey, { snapshot, prevSnapshot, restore: true }))
+        event.stopPropagation()
+      })
+      a.addEventListener('click', () => {
+        console.log('setting snapshot')
+        if (prevSnapshot === null) {
+          prevSnapshot = { ds: snapshot.ds, sm: new Map() }
+        }
+        this.renderSnapshot(snapshot, prevSnapshot)
+      })
+      fragment.insertBefore(el, null)
+      _prevSnap = snapshot
+    })
+    this.historyContainer.innerHTML = ''
+    this.historyContainer.insertBefore(fragment, null)
+  }
+  renderSnapshot (snapshot, prevSnapshot) {
+    this.editorView.dispatch(this.editorView.state.tr.setMeta(prosemirrorPluginKey, { snapshot, prevSnapshot }))
+    /**
+     * @type {Array<string|null>}
+     */
+    let colors = niceColors.slice()
+    let style = ''
+    snapshot.userMap.forEach((name, userid) => {
+      /**
+       * @type {any}
+       */
+      const randInt = name.split('').map(s => s.charCodeAt(0)).reduce((a, b) => a + b)
+      let color = null
+      let i = 0
+      for (; i < colors.length && color === null; i++) {
+        color = colors[(randInt + i) % colors.length]
+      }
+      if (color === null) {
+        colors = niceColors.slice()
+        i = 0
+        color = colors[randInt % colors.length]
+      }
+      colors[randInt % colors.length] = null
+      style += createUserCSS(userid, name, color, color + '69')
+    })
+    this.userStyleContainer.innerHTML = style
+  }
+  /**
+   * @param {Map<number, string>} [updatedUserMap] Maps from userid (yjs model) to account name (e.g. mail address)
+   */
+  snapshot (updatedUserMap = new Map()) {
+    const y = prosemirrorPluginKey.getState(this.editorView.state).y
+    const history = y.define('history', Y.Array)
+    const encoder = encoding.createEncoder()
+    historyProtocol.writeHistorySnapshot(encoder, y, updatedUserMap)
+    encoding.writeUint32(encoder, Math.floor(Date.now() / 1000))
+    history.push([encoding.toBuffer(encoder)])
+  }
+}

examples/prosemirror-schema.js

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+import { Schema } from 'prosemirror-model'
+
+const brDOM = ['br']
+
+const calcYchangeDomAttrs = (attrs, domAttrs = {}) => {
+  domAttrs = Object.assign({}, domAttrs)
+  if (attrs.ychange !== null) {
+    domAttrs.ychange_user = attrs.ychange.user
+    domAttrs.ychange_state = attrs.ychange.state
+  }
+  return domAttrs
+}
+
+// :: Object
+// [Specs](#model.NodeSpec) for the nodes defined in this schema.
+export const nodes = {
+  // :: NodeSpec The top level document node.
+  doc: {
+    content: 'block+'
+  },
+
+  // :: NodeSpec A plain paragraph textblock. Represented in the DOM
+  // as a `<p>` element.
+  paragraph: {
+    attrs: { ychange: { default: null } },
+    content: 'inline*',
+    group: 'block',
+    parseDOM: [{ tag: 'p' }],
+    toDOM (node) { return ['p', calcYchangeDomAttrs(node.attrs), 0] }
+  },
+
+  // :: NodeSpec A blockquote (`<blockquote>`) wrapping one or more blocks.
+  blockquote: {
+    attrs: { ychange: { default: null } },
+    content: 'block+',
+    group: 'block',
+    defining: true,
+    parseDOM: [{ tag: 'blockquote' }],
+    toDOM (node) { return ['blockquote', calcYchangeDomAttrs(node.attrs), 0] }
+  },
+
+  // :: NodeSpec A horizontal rule (`<hr>`).
+  horizontal_rule: {
+    attrs: { ychange: { default: null } },
+    group: 'block',
+    parseDOM: [{ tag: 'hr' }],
+    toDOM (node) {
+      return ['hr', calcYchangeDomAttrs(node.attrs)]
+    }
+  },
+
+  // :: NodeSpec A heading textblock, with a `level` attribute that
+  // should hold the number 1 to 6. Parsed and serialized as `<h1>` to
+  // `<h6>` elements.
+  heading: {
+    attrs: {
+      level: { default: 1 },
+      ychange: { default: null }
+    },
+    content: 'inline*',
+    group: 'block',
+    defining: true,
+    parseDOM: [{ tag: 'h1', attrs: { level: 1 } },
+      { tag: 'h2', attrs: { level: 2 } },
+      { tag: 'h3', attrs: { level: 3 } },
+      { tag: 'h4', attrs: { level: 4 } },
+      { tag: 'h5', attrs: { level: 5 } },
+      { tag: 'h6', attrs: { level: 6 } }],
+    toDOM (node) { return ['h' + node.attrs.level, calcYchangeDomAttrs(node.attrs), 0] }
+  },
+
+  // :: NodeSpec A code listing. Disallows marks or non-text inline
+  // nodes by default. Represented as a `<pre>` element with a
+  // `<code>` element inside of it.
+  code_block: {
+    attrs: { ychange: { default: null } },
+    content: 'text*',
+    marks: '',
+    group: 'block',
+    code: true,
+    defining: true,
+    parseDOM: [{ tag: 'pre', preserveWhitespace: 'full' }],
+    toDOM (node) { return ['pre', calcYchangeDomAttrs(node.attrs), ['code', 0]] }
+  },
+
+  // :: NodeSpec The text node.
+  text: {
+    group: 'inline'
+  },
+
+  // :: NodeSpec An inline image (`<img>`) node. Supports `src`,
+  // `alt`, and `href` attributes. The latter two default to the empty
+  // string.
+  image: {
+    inline: true,
+    attrs: {
+      ychange: { default: null },
+      src: {},
+      alt: { default: null },
+      title: { default: null }
+    },
+    group: 'inline',
+    draggable: true,
+    parseDOM: [{ tag: 'img[src]',
+      getAttrs (dom) {
+        return {
+          src: dom.getAttribute('src'),
+          title: dom.getAttribute('title'),
+          alt: dom.getAttribute('alt')
+        }
+      } }],
+    toDOM (node) {
+      const domAttrs = {
+        src: node.attrs.src,
+        title: node.attrs.title,
+        alt: node.attrs.alt
+      }
+      return ['img', calcYchangeDomAttrs(node.attrs, domAttrs)]
+    }
+  },
+
+  // :: NodeSpec A hard line break, represented in the DOM as `<br>`.
+  hard_break: {
+    inline: true,
+    group: 'inline',
+    selectable: false,
+    parseDOM: [{ tag: 'br' }],
+    toDOM () { return brDOM }
+  }
+}
+
+const emDOM = ['em', 0]; const strongDOM = ['strong', 0]; const codeDOM = ['code', 0]
+
+// :: Object [Specs](#model.MarkSpec) for the marks in the schema.
+export const marks = {
+  // :: MarkSpec A link. Has `href` and `title` attributes. `title`
+  // defaults to the empty string. Rendered and parsed as an `<a>`
+  // element.
+  link: {
+    attrs: {
+      href: {},
+      title: { default: null }
+    },
+    inclusive: false,
+    parseDOM: [{ tag: 'a[href]',
+      getAttrs (dom) {
+        return { href: dom.getAttribute('href'), title: dom.getAttribute('title') }
+      } }],
+    toDOM (node) { return ['a', node.attrs, 0] }
+  },
+
+  // :: MarkSpec An emphasis mark. Rendered as an `<em>` element.
+  // Has parse rules that also match `<i>` and `font-style: italic`.
+  em: {
+    parseDOM: [{ tag: 'i' }, { tag: 'em' }, { style: 'font-style=italic' }],
+    toDOM () { return emDOM }
+  },
+
+  // :: MarkSpec A strong mark. Rendered as `<strong>`, parse rules
+  // also match `<b>` and `font-weight: bold`.
+  strong: {
+    parseDOM: [{ tag: 'strong' },
+      // This works around a Google Docs misbehavior where
+      // pasted content will be inexplicably wrapped in `<b>`
+      // tags with a font-weight normal.
+      { tag: 'b', getAttrs: node => node.style.fontWeight !== 'normal' && null },
+      { style: 'font-weight', getAttrs: value => /^(bold(er)?|[5-9]\d{2,})$/.test(value) && null }],
+    toDOM () { return strongDOM }
+  },
+
+  // :: MarkSpec Code font mark. Represented as a `<code>` element.
+  code: {
+    parseDOM: [{ tag: 'code' }],
+    toDOM () { return codeDOM }
+  },
+  ychange: {
+    attrs: {
+      user: { default: null },
+      state: { default: null }
+    },
+    inclusive: false,
+    parseDOM: [{ tag: 'ychange' }],
+    toDOM (node) {
+      return ['ychange', { ychange_user: node.attrs.user, ychange_state: node.attrs.state }, 0]
+    }
+  }
+}
+
+// :: Schema
+// This schema rougly corresponds to the document schema used by
+// [CommonMark](http://commonmark.org/), minus the list elements,
+// which are defined in the [`prosemirror-schema-list`](#schema-list)
+// module.
+//
+// To reuse elements from this schema, extend or read from its
+// `spec.nodes` and `spec.marks` [properties](#model.Schema.spec).
+export const schema = new Schema({ nodes, marks })

examples/prosemirror.css

@@ -0,0 +1,330 @@
+.ProseMirror {
+  position: relative;
+}
+
+.ProseMirror {
+  word-wrap: break-word;
+  white-space: pre-wrap;
+  -webkit-font-variant-ligatures: none;
+  font-variant-ligatures: none;
+}
+
+.ProseMirror pre {
+  white-space: pre-wrap;
+}
+
+.ProseMirror li {
+  position: relative;
+}
+
+.ProseMirror-hideselection *::selection { background: transparent; }
+.ProseMirror-hideselection *::-moz-selection { background: transparent; }
+.ProseMirror-hideselection { caret-color: transparent; }
+
+.ProseMirror-selectednode {
+  outline: 2px solid #8cf;
+}
+
+/* Make sure li selections wrap around markers */
+
+li.ProseMirror-selectednode {
+  outline: none;
+}
+
+li.ProseMirror-selectednode:after {
+  content: "";
+  position: absolute;
+  left: -32px;
+  right: -2px; top: -2px; bottom: -2px;
+  border: 2px solid #8cf;
+  pointer-events: none;
+}
+.ProseMirror-textblock-dropdown {
+  min-width: 3em;
+}
+
+.ProseMirror-menu {
+  margin: 0 -4px;
+  line-height: 1;
+}
+
+.ProseMirror-tooltip .ProseMirror-menu {
+  width: -webkit-fit-content;
+  width: fit-content;
+  white-space: pre;
+}
+
+.ProseMirror-menuitem {
+  margin-right: 3px;
+  display: inline-block;
+}
+
+.ProseMirror-menuseparator {
+  border-right: 1px solid #ddd;
+  margin-right: 3px;
+}
+
+.ProseMirror-menu-dropdown, .ProseMirror-menu-dropdown-menu {
+  font-size: 90%;
+  white-space: nowrap;
+}
+
+.ProseMirror-menu-dropdown {
+  vertical-align: 1px;
+  cursor: pointer;
+  position: relative;
+  padding-right: 15px;
+}
+
+.ProseMirror-menu-dropdown-wrap {
+  padding: 1px 0 1px 4px;
+  display: inline-block;
+  position: relative;
+}
+
+.ProseMirror-menu-dropdown:after {
+  content: "";
+  border-left: 4px solid transparent;
+  border-right: 4px solid transparent;
+  border-top: 4px solid currentColor;
+  opacity: .6;
+  position: absolute;
+  right: 4px;
+  top: calc(50% - 2px);
+}
+
+.ProseMirror-menu-dropdown-menu, .ProseMirror-menu-submenu {
+  position: absolute;
+  background: white;
+  color: #666;
+  border: 1px solid #aaa;
+  padding: 2px;
+}
+
+.ProseMirror-menu-dropdown-menu {
+  z-index: 15;
+  min-width: 6em;
+}
+
+.ProseMirror-menu-dropdown-item {
+  cursor: pointer;
+  padding: 2px 8px 2px 4px;
+}
+
+.ProseMirror-menu-dropdown-item:hover {
+  background: #f2f2f2;
+}
+
+.ProseMirror-menu-submenu-wrap {
+  position: relative;
+  margin-right: -4px;
+}
+
+.ProseMirror-menu-submenu-label:after {
+  content: "";
+  border-top: 4px solid transparent;
+  border-bottom: 4px solid transparent;
+  border-left: 4px solid currentColor;
+  opacity: .6;
+  position: absolute;
+  right: 4px;
+  top: calc(50% - 4px);
+}
+
+.ProseMirror-menu-submenu {
+  display: none;
+  min-width: 4em;
+  left: 100%;
+  top: -3px;
+}
+
+.ProseMirror-menu-active {
+  background: #eee;
+  border-radius: 4px;
+}
+
+.ProseMirror-menu-active {
+  background: #eee;
+  border-radius: 4px;
+}
+
+.ProseMirror-menu-disabled {
+  opacity: .3;
+}
+
+.ProseMirror-menu-submenu-wrap:hover .ProseMirror-menu-submenu, .ProseMirror-menu-submenu-wrap-active .ProseMirror-menu-submenu {
+  display: block;
+}
+
+.ProseMirror-menubar {
+  border-top-left-radius: inherit;
+  border-top-right-radius: inherit;
+  position: relative;
+  min-height: 1em;
+  color: #666;
+  padding: 1px 6px;
+  top: 0; left: 0; right: 0;
+  border-bottom: 1px solid silver;
+  background: white;
+  z-index: 10;
+  -moz-box-sizing: border-box;
+  box-sizing: border-box;
+  overflow: visible;
+}
+
+.ProseMirror-icon {
+  display: inline-block;
+  line-height: .8;
+  vertical-align: -2px; /* Compensate for padding */
+  padding: 2px 8px;
+  cursor: pointer;
+}
+
+.ProseMirror-menu-disabled.ProseMirror-icon {
+  cursor: default;
+}
+
+.ProseMirror-icon svg {
+  fill: currentColor;
+  height: 1em;
+}
+
+.ProseMirror-icon span {
+  vertical-align: text-top;
+}
+.ProseMirror-gapcursor {
+  display: none;
+  pointer-events: none;
+  position: absolute;
+}
+
+.ProseMirror-gapcursor:after {
+  content: "";
+  display: block;
+  position: absolute;
+  top: -2px;
+  width: 20px;
+  border-top: 1px solid black;
+  animation: ProseMirror-cursor-blink 1.1s steps(2, start) infinite;
+}
+
+@keyframes ProseMirror-cursor-blink {
+  to {
+    visibility: hidden;
+  }
+}
+
+.ProseMirror-focused .ProseMirror-gapcursor {
+  display: block;
+}
+/* Add space around the hr to make clicking it easier */
+
+.ProseMirror-example-setup-style hr {
+  padding: 2px 10px;
+  border: none;
+  margin: 1em 0;
+}
+
+.ProseMirror-example-setup-style hr:after {
+  content: "";
+  display: block;
+  height: 1px;
+  background-color: silver;
+  line-height: 2px;
+}
+
+.ProseMirror ul, .ProseMirror ol {
+  padding-left: 30px;
+}
+
+.ProseMirror blockquote {
+  padding-left: 1em;
+  border-left: 3px solid #eee;
+  margin-left: 0; margin-right: 0;
+}
+
+.ProseMirror-example-setup-style img {
+  cursor: default;
+}
+
+.ProseMirror-prompt {
+  background: white;
+  padding: 5px 10px 5px 15px;
+  border: 1px solid silver;
+  position: fixed;
+  border-radius: 3px;
+  z-index: 11;
+  box-shadow: -.5px 2px 5px rgba(0, 0, 0, .2);
+}
+
+.ProseMirror-prompt h5 {
+  margin: 0;
+  font-weight: normal;
+  font-size: 100%;
+  color: #444;
+}
+
+.ProseMirror-prompt input[type="text"],
+.ProseMirror-prompt textarea {
+  background: #eee;
+  border: none;
+  outline: none;
+}
+
+.ProseMirror-prompt input[type="text"] {
+  padding: 0 4px;
+}
+
+.ProseMirror-prompt-close {
+  position: absolute;
+  left: 2px; top: 1px;
+  color: #666;
+  border: none; background: transparent; padding: 0;
+}
+
+.ProseMirror-prompt-close:after {
+  content: "✕";
+  font-size: 12px;
+}
+
+.ProseMirror-invalid {
+  background: #ffc;
+  border: 1px solid #cc7;
+  border-radius: 4px;
+  padding: 5px 10px;
+  position: absolute;
+  min-width: 10em;
+}
+
+.ProseMirror-prompt-buttons {
+  margin-top: 5px;
+  display: none;
+}
+#editor, .editor {
+  background: white;
+  color: black;
+  background-clip: padding-box;
+  border-radius: 4px;
+  border: 2px solid rgba(0, 0, 0, 0.2);
+  padding: 5px 0;
+  margin-bottom: 23px;
+}
+
+.ProseMirror p:first-child,
+.ProseMirror h1:first-child,
+.ProseMirror h2:first-child,
+.ProseMirror h3:first-child,
+.ProseMirror h4:first-child,
+.ProseMirror h5:first-child,
+.ProseMirror h6:first-child {
+  margin-top: 10px;
+}
+
+.ProseMirror {
+  padding: 4px 8px 4px 14px;
+  line-height: 1.2;
+  outline: none;
+}
+
+.ProseMirror p { margin-bottom: 1em }
+

examples/prosemirror.html

@@ -0,0 +1,117 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Yjs Prosemirror Example</title>
+    <link rel=stylesheet href="./prosemirror.css">
+    <style>
+      placeholder {
+        display: inline;
+        border: 1px solid #ccc;
+        color: #ccc;
+      }
+      placeholder:after {
+        content: "☁";
+        font-size: 200%;
+        line-height: 0.1;
+        font-weight: bold;
+      }
+      .ProseMirror img { max-width: 100px }
+      /* this is a rough fix for the first cursor position when the first paragraph is empty */
+      .ProseMirror > .ProseMirror-yjs-cursor:first-child {
+        margin-top: 16px;
+      }
+      .ProseMirror p:first-child, .ProseMirror h1:first-child, .ProseMirror h2:first-child, .ProseMirror h3:first-child, .ProseMirror h4:first-child, .ProseMirror h5:first-child, .ProseMirror h6:first-child {
+        margin-top: 16px
+      }
+      .ProseMirror-yjs-cursor {
+        position: absolute;
+        border-left: black;
+        border-left-style: solid;
+        border-left-width: 2px;
+        border-color: orange;
+        height: 1em;
+        word-break: normal;
+      }
+      .ProseMirror-yjs-cursor > div {
+        position: relative;
+        top: -1.05em;
+        font-size: 13px;
+        background-color: rgb(250, 129, 0);
+        font-family: serif;
+        font-style: normal;
+        font-weight: normal;
+        line-height: normal;
+        user-select: none;
+        color: white;
+        padding-left: 2px;
+        padding-right: 2px;
+      }
+      [ychange_state] {
+        position: relative;
+      }
+      [ychange_state]:hover::before {
+        content: attr(ychange_user);
+        background-color: #fa8100;
+        position: absolute;
+        top: -14px;
+        right: 0;
+        font-size: 12px;
+        padding: 0 2px;
+        border-radius: 3px 3px 0 0;
+        color: #fdfdfe;
+        user-select: none;
+        word-break: normal;
+      }
+      *[ychange_state='added'] {
+        background-color: #fa810069;
+      }
+      ychange[ychange_state='removed'] {
+        color: rgb(250, 129, 0);
+        text-decoration: line-through;
+      }
+      *:not(ychange)[ychange_state='removed'] {
+        background-color: #ff9494c9;
+        text-decoration: line-through;
+      }
+      img[ychange_state='removed'] {
+        padding: 2px;
+      }
+    </style>
+</head>
+<body>
+  <p>This example shows how to bind a YXmlFragment type to a <a href="http://prosemirror.net">Prosemirror</a> editor.</p>
+  <p>The content of this editor is shared with every client who visits this domain.</p>
+  <div class="code-html">
+
+<div id="editor" style="margin-bottom: 23px"></div>
+<div style="display: none" id="content"></div>
+  </div>
+  <!-- The actual source file for the following code is found in ./prosemirror.js. Run `npm run watch` to compile the files -->
+  <script class="code-js" src="./build/prosemirror.js" type="module">
+import * as Y from 'yjs'
+import { WebsocketProvider } from 'yjs/provider/websocket.js'
+import { prosemirrorPlugin, cursorPlugin } from 'yjs/bindings/prosemirror'
+
+import * as conf from './exampleConfig.js'
+
+import { EditorState } from 'prosemirror-state'
+import { EditorView } from 'prosemirror-view'
+import { DOMParser } from 'prosemirror-model'
+import { schema } from 'prosemirror-schema-basic'
+import { exampleSetup } from 'prosemirror-example-setup'
+
+const provider = new WebsocketProvider(conf.serverAddress)
+const ydocument = provider.get('prosemirror')
+const type = ydocument.define('prosemirror', Y.XmlFragment)
+
+const prosemirrorView = new EditorView(document.querySelector('#editor'), {
+  state: EditorState.create({
+    doc: DOMParser.fromSchema(schema).parse(document.querySelector('#content')),
+    plugins: exampleSetup({schema}).concat([prosemirrorPlugin(type), cursorPlugin])
+  })
+})
+
+window.example = { provider, ydocument, type, prosemirrorView }
+  </script>
+</body>
+</html>

examples/prosemirror.js

@@ -0,0 +1,25 @@
+import * as Y from 'yjs'
+import { WebsocketProvider } from 'y-websocket'
+import { prosemirrorPlugin, cursorPlugin } from 'y-prosemirror'
+
+import * as conf from './exampleConfig.js'
+
+import { EditorState } from 'prosemirror-state'
+import { EditorView } from 'prosemirror-view'
+import { DOMParser } from 'prosemirror-model'
+import { schema } from './prosemirror-schema.js'
+import { exampleSetup } from 'prosemirror-example-setup'
+// import { noteHistoryPlugin } from './prosemirror-history.js'
+
+const provider = new WebsocketProvider(conf.serverAddress)
+const ydocument = provider.get('prosemirror', { gc: false })
+const type = ydocument.define('prosemirror', Y.XmlFragment)
+
+const prosemirrorView = new EditorView(document.querySelector('#editor'), {
+  state: EditorState.create({
+    doc: DOMParser.fromSchema(schema).parse(document.querySelector('#content')),
+    plugins: exampleSetup({ schema }).concat([prosemirrorPlugin(type), cursorPlugin])
+  })
+})
+
+window.example = { provider, ydocument, type, prosemirrorView }

examples/quill.html

@@ -0,0 +1,51 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Yjs Quill Example</title>
+    <link rel="stylesheet" href="https://cdn.quilljs.com/1.3.6/quill.snow.css">
+  </head>
+<body>
+  <p>This example shows how to bind a YText type to <a href="https://quilljs.com">Quill</a> editor.</p>
+  <p>The content of this editor is shared with every client who visits this domain.</p>
+  <div class="code-html">
+<div id="quill-container">
+  <div id="quill">
+  </div>
+</div>
+  </div>
+  <!-- The actual source file for the following code is found in ./quill.js. Run `npm run watch` to compile the files -->
+  <script class="code-js" src="./build/quill.js" type="module">
+import * as Y from 'yjs'
+import { WebsocketProvider } from 'yjs/provider/websocket.js'
+import { QuillBinding } from 'yjs/bindings/quill.js'
+
+import * as conf from './exampleConfig.js'
+
+import Quill from 'quill'
+
+const provider = new WebsocketProvider(conf.serverAddress)
+const ydocument = provider.get('quill')
+const ytext = ydocument.define('quill', Y.Text)
+
+const quill = new Quill('#quill-container', {
+  modules: {
+    toolbar: [
+      [{ header: [1, 2, false] }],
+      ['bold', 'italic', 'underline'],
+      ['image', 'code-block'],
+      [{ color: [] }, { background: [] }], // Snow theme fills in values
+      [{ script: 'sub' }, { script: 'super' }],
+      ['link', 'image'],
+      ['link', 'code-block'],
+      [{ list: 'ordered' }, { list: 'bullet' }]
+    ]
+  },
+  placeholder: 'Compose an epic...',
+  theme: 'snow' // or 'bubble'
+})
+
+window.quillBinding = new QuillBinding(ytext, quill)
+
+  </script>
+</body>
+</html>

examples/quill.js

@@ -0,0 +1,30 @@
+import * as Y from '../src/index.js'
+import { WebsocketProvider } from 'y-websocket'
+import { QuillBinding } from 'y-quill'
+
+import * as conf from './exampleConfig.js'
+
+import Quill from 'quill'
+
+const provider = new WebsocketProvider(conf.serverAddress)
+const ydocument = provider.get('quill')
+const ytext = ydocument.define('quill', Y.Text)
+
+const quill = new Quill('#quill-container', {
+  modules: {
+    toolbar: [
+      [{ header: [1, 2, false] }],
+      ['bold', 'italic', 'underline'],
+      ['image', 'code-block'],
+      [{ color: [] }, { background: [] }], // Snow theme fills in values
+      [{ script: 'sub' }, { script: 'super' }],
+      ['link', 'image'],
+      ['link', 'code-block'],
+      [{ list: 'ordered' }, { list: 'bullet' }]
+    ]
+  },
+  placeholder: 'Compose an epic...',
+  theme: 'snow' // or 'bubble'
+})
+
+window.quillBinding = new QuillBinding(ytext, quill)

examples/style.css

@@ -0,0 +1,29 @@
+footer img {
+  display: none;
+}
+
+nav .title h1 a {
+  display: none;
+}
+
+footer {
+  background-color: #b93c1d;
+}
+
+#resizer {
+  background-color: #b93c1d;
+}
+
+.main section article.readme h1:first-child img {
+  display: none;
+}
+
+.main section article.readme h1:first-child {
+  margin-bottom: 16px;
+  margin-top: 30px;
+}
+
+.main section article.readme h1:first-child::before {
+  content: "Yjs";
+  font-size: 2em;
+}

examples/textarea.html

@@ -0,0 +1,32 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Yjs Textarea Example</title>
+</head>
+<body>
+  <p>This example shows how to bind a YText type to a DOM Textarea.</p>
+  <p>The content of this textarea is shared with every client who visits this domain.</p>
+  <div class="code-html">
+
+<textarea style="width:80%;" rows=40 autocomplete="off" autocorrect="off" autocapitalize="off" spellcheck="false"></textarea>
+  </div>
+  <!-- The actual source file for the following code is found in ./textarea.js. Run `npm run watch` to compile the files -->
+  <script class="code-js" src="./build/textarea.js" type="module">
+import * as Y from 'yjs'
+import { WebsocketProvider } from 'yjs/provider/websocket.js'
+import { TextareaBinding } from 'yjs/bindings/textarea.js'
+
+import * as conf from './exampleConfig.js'
+
+const provider = new WebsocketProvider(conf.serverAddress)
+const ydocument = provider.get('textarea')
+const type = ydocument.define('textarea', Y.Text)
+const textarea = document.querySelector('textarea')
+const binding = new TextareaBinding(type, textarea)
+
+window.textareaExample = {
+  provider, ydocument, type, textarea, binding
+}
+  </script>
+</body>
+</html>

examples/textarea.js

@@ -0,0 +1,14 @@
+import { WebsocketProvider } from 'y-websocket'
+import { TextareaBinding } from 'y-textarea'
+
+import * as conf from './exampleConfig.js'
+
+const provider = new WebsocketProvider(conf.serverAddress)
+const ydocument = provider.get('textarea')
+const type = ydocument.getText('textarea')
+const textarea = document.querySelector('textarea')
+const binding = new TextareaBinding(type, textarea)
+
+window.textareaExample = {
+  provider, ydocument, type, textarea, binding
+}

gulpfile.helper.js

@@ -1,214 +0,0 @@
-
-var $ = require('gulp-load-plugins')()
-var minimist = require('minimist')
-var browserify = require('browserify')
-var source = require('vinyl-source-stream')
-var buffer = require('vinyl-buffer')
-
-module.exports = function (gulp, helperOptions) {
-  var runSequence = require('run-sequence').use(gulp)
-  var options = minimist(process.argv.slice(2), {
-    string: ['modulename', 'export', 'name', 'port', 'testfiles', 'es6'],
-    default: {
-      moduleName: helperOptions.moduleName,
-      targetName: helperOptions.targetName,
-      export: 'ignore',
-      port: '8888',
-      testfiles: '**/*.spec.js',
-      es6: false,
-      browserify: helperOptions.browserify != null ? helperOptions.browserify : false,
-      includeRuntime: helperOptions.includeRuntime || false,
-      debug: false
-    }
-  })
-  if (options.es6 !== false) {
-    options.es6 = true
-  }
-  var files = {
-    dist: helperOptions.entry,
-    specs: helperOptions.specs,
-    src: './src/**/*.js'
-  }
-
-  if (options.includeRuntime) {
-    files.distEs5 = ['node_modules/regenerator/runtime.js', files.dist]
-  } else {
-    files.distEs5 = [files.dist]
-  }
-
-  var header = require('gulp-header')
-  var banner = ['/**',
-    ' * <%= pkg.name %> - <%= pkg.description %>',
-    ' * @version v<%= pkg.version %>',
-    ' * @link <%= pkg.homepage %>',
-    ' * @license <%= pkg.license %>',
-    ' */',
-    ''].join('\n')
-
-  gulp.task('dist:es5', function () {
-    var babelOptions = {
-      presets: ['es2015']
-    }
-    return (browserify({
-      entries: files.distEs5,
-      debug: true,
-      standalone: options.moduleName
-    }).transform('babelify', babelOptions)
-      .bundle()
-      .pipe(source(options.targetName))
-      .pipe(buffer())
-      .pipe($.sourcemaps.init({loadMaps: true}))
-      .pipe($.if(!options.debug, $.uglify().on('error', function (e) {
-        console.log('\x07', e.message, JSON.stringify(e)); return this.end()
-      })))
-      .pipe(header(banner, { pkg: require('./package.json') }))
-      .pipe($.sourcemaps.write('.'))
-      .pipe(gulp.dest('./dist/')))
-  })
-
-  gulp.task('dist:es6', function () {
-    return (browserify({
-      entries: files.dist,
-      debug: true,
-      standalone: options.moduleName
-    }).bundle()
-      .pipe(source(options.targetName))
-      .pipe(buffer())
-      .pipe($.sourcemaps.init({loadMaps: true}))
-      // .pipe($.uglify()) -- generators not yet supported see #448
-      .pipe($.rename({
-        extname: '.es6'
-      }))
-      .pipe(header(banner, { pkg: require('./package.json') }))
-      .pipe($.sourcemaps.write('.'))
-      .pipe(gulp.dest('./dist/')))
-  })
-
-  gulp.task('dist', ['dist:es6', 'dist:es5'])
-
-  gulp.task('watch:dist', function (cb) {
-    options.debug = true
-    gulp.src(['./README.md'])
-      .pipe($.watch('./README.md'))
-      .pipe(gulp.dest('./dist/'))
-    runSequence('dist', function () {
-      gulp.watch(files.src.concat('./README.md'), ['dist'])
-      cb()
-    })
-  })
-
-  gulp.task('dev:node', ['test'], function () {
-    gulp.watch(files.src, ['test'])
-  })
-
-  gulp.task('spec-build', function () {
-    var browserify = require('browserify')
-    var source = require('vinyl-source-stream')
-    var buffer = require('vinyl-buffer')
-
-    return browserify({
-      entries: files.specs, // .concat(files.distEs5),
-      debug: true
-    })// .transform('babelify', { presets: ['es2015'] })
-      .bundle()
-      .pipe(source('specs.js'))
-      .pipe(buffer())
-      // .pipe($.sourcemaps.init({loadMaps: true}))
-      // .pipe($.sourcemaps.write('.'))
-      .pipe(gulp.dest('./build/'))
-  })
-
-  gulp.task('dev:browser', ['spec-build'], function () {
-    gulp.watch(files.src, ['spec-build'])
-    return gulp.src('./build/specs.js')
-      .pipe($.jasmineBrowser.specRunner())
-      .pipe($.jasmineBrowser.server({port: options.port}))
-  })
-
-  gulp.task('test', function () {
-    return gulp.src(files.specs)
-      .pipe($.jasmine({
-        verbose: true,
-        includeStuckTrace: true
-      }))
-  })
-
-  gulp.task('updateSubmodule', function () {
-    return gulp.src('./package.json', {read: false})
-      .pipe($.shell([
-        'git submodule update --init',
-        'cd dist && git pull origin dist'
-      ]))
-  })
-
-  gulp.task('bump', function (cb) {
-    gulp.src(['./package.json', './bower.json', './dist/bower.json'], {base: '.'})
-      .pipe($.prompt.prompt({
-        type: 'checkbox',
-        name: 'bump',
-        message: 'What type of bump would you like to do?',
-        choices: ['patch', 'minor', 'major']
-      }, function (res) {
-        if (res.bump.length === 0) {
-          console.info('You have to select a bump type. Now I\'m going to use "patch" as bump type..')
-        }
-        var bumptype = res.bump[0]
-        if (bumptype === 'major') {
-          runSequence('bump_major', cb)
-        } else if (bumptype === 'minor') {
-          runSequence('bump_minor', cb)
-        } else {
-          runSequence('bump_patch', cb)
-        }
-      }))
-  })
-  gulp.task('bump_patch', function () {
-    return gulp.src(['./package.json', './bower.json', './dist/bower.json'], {base: '.'})
-      .pipe($.bump({type: 'patch'}))
-      .pipe(gulp.dest('./'))
-  })
-  gulp.task('bump_minor', function () {
-    return gulp.src(['./package.json', './bower.json', './dist/bower.json'], {base: '.'})
-      .pipe($.bump({type: 'minor'}))
-      .pipe(gulp.dest('./'))
-  })
-  gulp.task('bump_major', function () {
-    return gulp.src(['./package.json', './bower.json', './dist/bower.json'], {base: '.'})
-      .pipe($.bump({type: 'major'}))
-      .pipe(gulp.dest('./'))
-  })
-
-  gulp.task('publish_commits', function () {
-    return gulp.src('./package.json')
-        .pipe($.prompt.confirm({
-          message: 'Are you sure you want to publish this release?',
-          default: false
-        }))
-        .pipe($.shell([
-          'cp README.md dist',
-          'standard',
-          'echo "Deploying version <%= getVersion(file.path) %>"',
-          'git pull',
-          'cd ./dist/ && git add -A',
-          'cd ./dist/ && git commit -am "Deploy <%= getVersion(file.path) %>" -n',
-          'cd ./dist/ && git push origin HEAD:dist',
-          'cd ./dist/ && git tag -a v<%= getVersion(file.path) %> -m "Release <%= getVersion(file.path) %>"',
-          'cd ./dist/ && git push origin --tags',
-          'git commit -am "Release <%= getVersion(file.path) %>" -n',
-          'git push',
-          'npm publish',
-          'echo Finished'
-        ], {
-          templateData: {
-            getVersion: function () {
-              return JSON.parse(String.fromCharCode.apply(null, this.file._contents)).version
-            }
-          }
-        }))
-  })
-
-  gulp.task('publish', function (cb) {
-    /* TODO: include 'test',*/
-    runSequence('updateSubmodule', 'bump', 'dist', 'publish_commits', cb)
-  })
-}

gulpfile.js

@@ -1,104 +0,0 @@
-/* eslint-env node */
-
-/** Gulp Commands
-
-  gulp command*
-    [--export ModuleType]
-    [--name ModuleName]
-    [--testport TestPort]
-    [--testfiles TestFiles]
-
-  Module name (ModuleName):
-    Compile this to "y.js" (default)
-
-  Supported module types (ModuleType):
-    - amd
-    - amdStrict
-    - common
-    - commonStrict
-    - ignore (default)
-    - system
-    - umd
-    - umdStrict
-
-  Test port (TestPort):
-    Serve the specs on port 8888 (default)
-
-  Test files (TestFiles):
-    Specify which specs to use!
-
-  Commands:
-    - build:deploy
-        Build this library for deployment (es6->es5, minified)
-    - dev:browser
-        Watch the ./src directory.
-        Builds the library on changes.
-        Starts an http-server and serves the test suite on http://127.0.0.1:8888.
-    - dev:node
-        Watch the ./src directory.
-        Builds and specs the library on changes.
-        Usefull to run with node-inspector.
-        `node-debug $(which gulp) dev:node
-    - test:
-        Test this library
-*/
-
-var gulp = require('gulp')
-var $ = require('gulp-load-plugins')()
-var runSequence = require('run-sequence').use(gulp)
-
-require('./gulpfile.helper.js')(gulp, {
-  polyfills: [],
-  entry: './src/y.js',
-  targetName: 'y.js',
-  moduleName: 'Y',
-  includeRuntime: true,
-  specs: [
-    './src/Database.spec.js',
-    '../y-array/src/Array.spec.js',
-    '../y-map/src/Map.spec.js'
-  ]
-})
-
-gulp.task('dev:examples', ['watch:dist'], function () {
-  // watch all distfiles and copy them to bower_components
-  var distfiles = ['./dist/*.{js,es6}', './dist/*.{js,es6}.map', '../y-*/dist/*.{js,es6}', '../y-*/dist/*.{js,es6}.map']
-  gulp.src(distfiles)
-    .pipe($.watch(distfiles))
-    .pipe($.rename(function (path) {
-      var dir = path.dirname.split(/[\\\/]/)[0]
-      console.log(JSON.stringify(path))
-      path.dirname = dir === '.' ? 'yjs' : dir
-    }))
-    .pipe(gulp.dest('./dist/Examples/bower_components/'))
-
-  return $.serve('dist/Examples/')()
-})
-
-gulp.task('default', ['updateSubmodule'], function (cb) {
-  gulp.src('package.json')
-    .pipe($.prompt.prompt({
-      type: 'checkbox',
-      name: 'tasks',
-      message: 'Which tasks would you like to run?',
-      choices: [
-        'test                    Test this project',
-        'dev:examples            Serve the examples directory in ./dist/',
-        'dev:browser             Watch files & serve the testsuite for the browser',
-        'dev:nodejs              Watch filse & test this project with nodejs',
-        'bump                    Bump the current state of the project',
-        'publish                 Publish this project. Creates a github tag',
-        'dist                    Build the distribution files'
-      ]
-    }, function (res) {
-      var tasks = res.tasks.map(function (task) {
-        return task.split(' ')[0]
-      })
-      if (tasks.length > 0) {
-        console.info('gulp ' + tasks.join(' '))
-        runSequence(tasks, cb)
-      } else {
-        console.info('Ok, .. goodbye')
-      }
-    }))
-})

package.json

@@ -1,24 +1,41 @@
 {
   "name": "yjs",
-  "version": "12.3.1",
-  "description": "A framework for real-time p2p shared editing on any data",
-  "main": "./src/y.js",
+  "version": "13.0.0-78",
+  "description": "A ",
+  "main": "./dist/yjs.js",
+  "module": "./dist/yjs.mjs'",
+  "sideEffects": false,
   "scripts": {
-    "test": "node --harmony ./node_modules/.bin/gulp test",
-    "lint": "./node_modules/.bin/standard"
+    "test": "npm run dist && PRODUCTION=1 node ./dist/tests.js --repitition-time 50 --production",
+    "test-exhaustive": "npm run lint && npm run dist && node ./dist/tests.js --repitition-time 10000",
+    "dist": "rm -rf dist examples/build && rollup -c",
+    "watch": "rollup -wc",
+    "lint": "standard && tsc",
+    "docs": "rm -rf docs; jsdoc --configure ./.jsdoc.json --verbose --readme ./README.v13.md --package ./package.json || true",
+    "serve-docs": "npm run docs && serve ./docs/",
+    "postversion": "npm run lint && PRODUCTION=1 npm run dist && node ./dist/tests.js --repitition-time 1000",
+    "debug": "concurrently 'live-server --port=3443 --entry-file=test.html' 'npm run watch'",
+    "trace-deopt": "clear && rollup -c  && node --trace-deopt dist/test.js",
+    "trace-opt": "clear && rollup -c  && node --trace-opt dist/test.js"
   },
-  "pre-commit": [
-    "lint",
-    "test"
+  "files": [
+    "dist/*",
+    "examples/*",
+    "docs/*",
+    "README.md",
+    "LICENSE"
   ],
+  "dictionaries": {
+    "doc": "docs",
+    "example": "examples",
+    "test": "tests"
+  },
   "standard": {
-    "parser": "babel-eslint",
     "ignore": [
-      "build/**",
-      "dist/**",
-      "declarations/**",
-      "./y.js",
-      "./y.js.map"
+      "/dist",
+      "/node_modules",
+      "/docs",
+      "/examples/build"
     ]
   },
   "repository": {
@@ -26,13 +43,7 @@
     "url": "https://github.com/y-js/yjs.git"
   },
   "keywords": [
-    "Yjs",
-    "OT",
-    "Collaboration",
-    "Synchronization",
-    "ShareJS",
-    "Coweb",
-    "Concurrency"
+    "crdt"
   ],
   "author": "Kevin Jahns",
   "email": "kevin.jahns@rwth-aachen.de",
@@ -41,42 +52,29 @@
     "url": "https://github.com/y-js/yjs/issues"
   },
   "homepage": "http://y-js.org",
-  "devDependencies": {
-    "babel-eslint": "^5.0.0-beta6",
-    "babel-plugin-transform-runtime": "^6.1.18",
-    "babel-preset-es2015": "^6.1.18",
-    "babelify": "^7.2.0",
-    "browserify": "^12.0.1",
-    "eslint": "^1.10.2",
-    "gulp": "^3.9.0",
-    "gulp-bump": "^1.0.0",
-    "gulp-concat": "^2.6.0",
-    "gulp-filter": "^3.0.1",
-    "gulp-git": "^1.6.0",
-    "gulp-header": "^1.8.8",
-    "gulp-if": "^2.0.0",
-    "gulp-jasmine": "^2.0.1",
-    "gulp-jasmine-browser": "^0.2.3",
-    "gulp-load-plugins": "^1.0.0",
-    "gulp-prompt": "^0.1.2",
-    "gulp-rename": "^1.2.2",
-    "gulp-serve": "^1.2.0",
-    "gulp-shell": "^0.5.1",
-    "gulp-sourcemaps": "^1.5.2",
-    "gulp-tag-version": "^1.3.0",
-    "gulp-uglify": "^2.0.0",
-    "gulp-util": "^3.0.6",
-    "gulp-watch": "^4.3.5",
-    "minimist": "^1.2.0",
-    "pre-commit": "^1.1.1",
-    "regenerator": "^0.8.42",
-    "run-sequence": "^1.1.4",
-    "seedrandom": "^2.4.2",
-    "standard": "^5.2.2",
-    "vinyl-buffer": "^1.0.0",
-    "vinyl-source-stream": "^1.1.0"
-  },
   "dependencies": {
-    "debug": "^2.6.3"
+    "lib0": "0.0.0"
+  },
+  "devDependencies": {
+    "codemirror": "^5.42.0",
+    "concurrently": "^3.6.1",
+    "esdoc": "^1.1.0",
+    "esdoc-standard-plugin": "^1.0.0",
+    "jsdoc": "^3.5.5",
+    "live-server": "^1.2.1",
+    "prosemirror-example-setup": "^1.0.1",
+    "prosemirror-schema-basic": "^1.0.0",
+    "prosemirror-state": "^1.2.2",
+    "prosemirror-view": "^1.6.5",
+    "quill": "^1.3.6",
+    "quill-cursors": "^1.0.3",
+    "rollup": "^1.1.2",
+    "rollup-cli": "^1.0.9",
+    "rollup-plugin-commonjs": "^9.2.0",
+    "rollup-plugin-node-resolve": "^4.0.0",
+    "rollup-plugin-terser": "^4.0.4",
+    "standard": "^11.0.1",
+    "tui-jsdoc-template": "^1.2.2",
+    "typescript": "^3.3.3333"
   }
 }

rollup.config.js

@@ -0,0 +1,105 @@
+import nodeResolve from 'rollup-plugin-node-resolve'
+import commonjs from 'rollup-plugin-commonjs'
+import { terser } from 'rollup-plugin-terser'
+
+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 `${process.cwd()}/src/index.js`
+    }
+    if (customModules.has(importee.split('/')[0])) {
+      return `${process.cwd()}/../${importee}/src/${importee}.js`
+    }
+    if (customLibModules.has(importee.split('/')[0])) {
+      return `${process.cwd()}/../${importee}`
+    }
+    return null
+  }
+}
+
+const minificationPlugins = process.env.PRODUCTION ? [terser({
+  module: true,
+  compress: {
+    hoist_vars: true,
+    module: true,
+    passes: 5,
+    pure_getters: true,
+    unsafe_comps: true,
+    unsafe_undefined: true
+  },
+  mangle: {
+    toplevel: true
+  }
+})] : []
+
+export default [{
+  input: './src/index.js',
+  output: [{
+    name: 'Y',
+    file: 'dist/yjs.js',
+    format: 'cjs',
+    sourcemap: true,
+    paths: path => {
+      if (/^lib0\//.test(path)) {
+        return `lib0/dist/${path.slice(5)}`
+      }
+      return path
+    }
+  }, {
+    name: 'Y',
+    file: 'dist/yjs.mjs',
+    format: 'es',
+    sourcemap: true
+  }],
+  external: id => /^lib0\//.test(id)
+}, {
+  input: './tests/index.js',
+  output: {
+    name: 'test',
+    file: 'dist/tests.js',
+    format: 'iife',
+    sourcemap: true
+  },
+  plugins: [
+    debugResolve,
+    nodeResolve({
+      sourcemap: true,
+      module: true,
+      browser: true
+    }),
+    commonjs()
+  ]
+}, {
+  input: ['./examples/codemirror.js', './examples/textarea.js'], // './examples/quill.js', './examples/dom.js', './examples/prosemirror.js'
+  output: {
+    dir: 'examples/build',
+    format: 'esm',
+    sourcemap: true
+  },
+  plugins: [
+    debugResolve,
+    nodeResolve({
+      sourcemap: true,
+      module: true,
+      browser: true
+    }),
+    commonjs(),
+    ...minificationPlugins
+  ]
+}]

src/Connector.js

@@ -1,496 +0,0 @@
-/* @flow */
-'use strict'
-
-function canRead (auth) { return auth === 'read' || auth === 'write' }
-function canWrite (auth) { return auth === 'write' }
-
-module.exports = function (Y/* :any */) {
-  class AbstractConnector {
-    /* ::
-    y: YConfig;
-    role: SyncRole;
-    connections: Object;
-    isSynced: boolean;
-    userEventListeners: Array<Function>;
-    whenSyncedListeners: Array<Function>;
-    currentSyncTarget: ?UserId;
-    syncingClients: Array<UserId>;
-    forwardToSyncingClients: boolean;
-    debug: boolean;
-    syncStep2: Promise;
-    userId: UserId;
-    send: Function;
-    broadcast: Function;
-    broadcastOpBuffer: Array<Operation>;
-    protocolVersion: number;
-    */
-    /*
-      opts contains the following information:
-       role : String Role of this client ("master" or "slave")
-       userId : String Uniquely defines the user.
-       debug: Boolean Whether to print debug messages (optional)
-    */
-    constructor (y, opts) {
-      this.y = y
-      if (opts == null) {
-        opts = {}
-      }
-      // Prefer to receive untransformed operations. This does only work if
-      // this client receives operations from only one other client.
-      // In particular, this does not work with y-webrtc.
-      // It will work with y-websockets-client
-      this.preferUntransformed = opts.preferUntransformed || false
-      if (opts.role == null || opts.role === 'master') {
-        this.role = 'master'
-      } else if (opts.role === 'slave') {
-        this.role = 'slave'
-      } else {
-        throw new Error("Role must be either 'master' or 'slave'!")
-      }
-      this.log = Y.debug('y:connector')
-      this.logMessage = Y.debug('y:connector-message')
-      this.y.db.forwardAppliedOperations = opts.forwardAppliedOperations || false
-      this.role = opts.role
-      this.connections = {}
-      this.isSynced = false
-      this.userEventListeners = []
-      this.whenSyncedListeners = []
-      this.currentSyncTarget = null
-      this.syncingClients = []
-      this.forwardToSyncingClients = opts.forwardToSyncingClients !== false
-      this.debug = opts.debug === true
-      this.syncStep2 = Promise.resolve()
-      this.broadcastOpBuffer = []
-      this.protocolVersion = 11
-      this.authInfo = opts.auth || null
-      this.checkAuth = opts.checkAuth || function () { return Promise.resolve('write') } // default is everyone has write access
-      if (opts.generateUserId === true) {
-        this.setUserId(Y.utils.generateGuid())
-      }
-    }
-    resetAuth (auth) {
-      if (this.authInfo !== auth) {
-        this.authInfo = auth
-        this.broadcast({
-          type: 'auth',
-          auth: this.authInfo
-        })
-      }
-    }
-    reconnect () {
-      this.log('reconnecting..')
-      return this.y.db.startGarbageCollector()
-    }
-    disconnect () {
-      this.log('discronnecting..')
-      this.connections = {}
-      this.isSynced = false
-      this.currentSyncTarget = null
-      this.syncingClients = []
-      this.whenSyncedListeners = []
-      this.y.db.stopGarbageCollector()
-      return this.y.db.whenTransactionsFinished()
-    }
-    repair () {
-      this.log('Repairing the state of Yjs. This can happen if messages get lost, and Yjs detects that something is wrong. If this happens often, please report an issue here: https://github.com/y-js/yjs/issues')
-      for (var name in this.connections) {
-        this.connections[name].isSynced = false
-      }
-      this.isSynced = false
-      this.currentSyncTarget = null
-      this.findNextSyncTarget()
-    }
-    setUserId (userId) {
-      if (this.userId == null) {
-        this.log('Set userId to "%s"', userId)
-        this.userId = userId
-        return this.y.db.setUserId(userId)
-      } else {
-        return null
-      }
-    }
-    onUserEvent (f) {
-      this.userEventListeners.push(f)
-    }
-    removeUserEventListener (f) {
-      this.userEventListeners = this.userEventListeners.filter(g => { f !== g })
-    }
-    userLeft (user) {
-      if (this.connections[user] != null) {
-        this.log('User left: %s', user)
-        delete this.connections[user]
-        if (user === this.currentSyncTarget) {
-          this.currentSyncTarget = null
-          this.findNextSyncTarget()
-        }
-        this.syncingClients = this.syncingClients.filter(function (cli) {
-          return cli !== user
-        })
-        for (var f of this.userEventListeners) {
-          f({
-            action: 'userLeft',
-            user: user
-          })
-        }
-      }
-    }
-    userJoined (user, role) {
-      if (role == null) {
-        throw new Error('You must specify the role of the joined user!')
-      }
-      if (this.connections[user] != null) {
-        throw new Error('This user already joined!')
-      }
-      this.log('User joined: %s', user)
-      this.connections[user] = {
-        isSynced: false,
-        role: role
-      }
-      for (var f of this.userEventListeners) {
-        f({
-          action: 'userJoined',
-          user: user,
-          role: role
-        })
-      }
-      if (this.currentSyncTarget == null) {
-        this.findNextSyncTarget()
-      }
-    }
-    // Execute a function _when_ we are connected.
-    // If not connected, wait until connected
-    whenSynced (f) {
-      if (this.isSynced) {
-        f()
-      } else {
-        this.whenSyncedListeners.push(f)
-      }
-    }
-    findNextSyncTarget () {
-      if (this.currentSyncTarget != null) {
-        return // "The current sync has not finished!"
-      }
-
-      var syncUser = null
-      for (var uid in this.connections) {
-        if (!this.connections[uid].isSynced) {
-          syncUser = uid
-          break
-        }
-      }
-      var conn = this
-      if (syncUser != null) {
-        this.currentSyncTarget = syncUser
-        this.y.db.requestTransaction(function *() {
-          var stateSet = yield* this.getStateSet()
-          var deleteSet = yield* this.getDeleteSet()
-          var answer = {
-            type: 'sync step 1',
-            stateSet: stateSet,
-            deleteSet: deleteSet,
-            protocolVersion: conn.protocolVersion,
-            auth: conn.authInfo
-          }
-          if (conn.preferUntransformed && Object.keys(stateSet).length === 0) {
-            answer.preferUntransformed = true
-          }
-          conn.send(syncUser, answer)
-        })
-      } else {
-        if (!conn.isSynced) {
-          this.y.db.requestTransaction(function *() {
-            if (!conn.isSynced) {
-              // it is crucial that isSynced is set at the time garbageCollectAfterSync is called
-              conn.isSynced = true
-              yield* this.garbageCollectAfterSync()
-              // call whensynced listeners
-              for (var f of conn.whenSyncedListeners) {
-                f()
-              }
-              conn.whenSyncedListeners = []
-            }
-          })
-        }
-      }
-    }
-    send (uid, message) {
-      this.log('Send \'%s\' to %s', message.type, uid)
-      this.logMessage('Message: %j', message)
-    }
-    broadcast (message) {
-      this.log('Broadcast \'%s\'', message.type)
-      this.logMessage('Message: %j', message)
-    }
-    /*
-      Buffer operations, and broadcast them when ready.
-    */
-    broadcastOps (ops) {
-      ops = ops.map(function (op) {
-        return Y.Struct[op.struct].encode(op)
-      })
-      var self = this
-      function broadcastOperations () {
-        if (self.broadcastOpBuffer.length > 0) {
-          self.broadcast({
-            type: 'update',
-            ops: self.broadcastOpBuffer
-          })
-          self.broadcastOpBuffer = []
-        }
-      }
-      if (this.broadcastOpBuffer.length === 0) {
-        this.broadcastOpBuffer = ops
-        if (this.y.db.transactionInProgress) {
-          this.y.db.whenTransactionsFinished().then(broadcastOperations)
-        } else {
-          setTimeout(broadcastOperations, 0)
-        }
-      } else {
-        this.broadcastOpBuffer = this.broadcastOpBuffer.concat(ops)
-      }
-    }
-    /*
-      You received a raw message, and you know that it is intended for Yjs. Then call this function.
-    */
-    receiveMessage (sender/* :UserId */, message/* :Message */) {
-      if (sender === this.userId) {
-        return Promise.resolve()
-      }
-      this.log('Receive \'%s\' from %s', message.type, sender)
-      this.logMessage('Message: %j', message)
-      if (message.protocolVersion != null && message.protocolVersion !== this.protocolVersion) {
-        this.log(
-          `You tried to sync with a yjs instance that has a different protocol version
-          (You: ${this.protocolVersion}, Client: ${message.protocolVersion}).
-          The sync was stopped. You need to upgrade your dependencies (especially Yjs & the Connector)!
-          `)
-        this.send(sender, {
-          type: 'sync stop',
-          protocolVersion: this.protocolVersion
-        })
-        return Promise.reject('Incompatible protocol version')
-      }
-      if (message.auth != null && this.connections[sender] != null) {
-        // authenticate using auth in message
-        var auth = this.checkAuth(message.auth, this.y)
-        this.connections[sender].auth = auth
-        auth.then(auth => {
-          for (var f of this.userEventListeners) {
-            f({
-              action: 'userAuthenticated',
-              user: sender,
-              auth: auth
-            })
-          }
-        })
-      } else if (this.connections[sender] != null && this.connections[sender].auth == null) {
-        // authenticate without otherwise
-        this.connections[sender].auth = this.checkAuth(null, this.y)
-      }
-      if (this.connections[sender] != null && this.connections[sender].auth != null) {
-        return this.connections[sender].auth.then((auth) => {
-          if (message.type === 'sync step 1' && canRead(auth)) {
-            let conn = this
-            let m = message
-
-            this.y.db.requestTransaction(function *() {
-              var currentStateSet = yield* this.getStateSet()
-              if (canWrite(auth)) {
-                yield* this.applyDeleteSet(m.deleteSet)
-              }
-
-              var ds = yield* this.getDeleteSet()
-              var answer = {
-                type: 'sync step 2',
-                stateSet: currentStateSet,
-                deleteSet: ds,
-                protocolVersion: this.protocolVersion,
-                auth: this.authInfo
-              }
-              if (message.preferUntransformed === true && Object.keys(m.stateSet).length === 0) {
-                answer.osUntransformed = yield* this.getOperationsUntransformed()
-              } else {
-                answer.os = yield* this.getOperations(m.stateSet)
-              }
-              conn.send(sender, answer)
-              if (this.forwardToSyncingClients) {
-                conn.syncingClients.push(sender)
-                setTimeout(function () {
-                  conn.syncingClients = conn.syncingClients.filter(function (cli) {
-                    return cli !== sender
-                  })
-                  conn.send(sender, {
-                    type: 'sync done'
-                  })
-                }, 5000) // TODO: conn.syncingClientDuration)
-              } else {
-                conn.send(sender, {
-                  type: 'sync done'
-                })
-              }
-            })
-          } else if (message.type === 'sync step 2' && canWrite(auth)) {
-            var db = this.y.db
-            var defer = {}
-            defer.promise = new Promise(function (resolve) {
-              defer.resolve = resolve
-            })
-            this.syncStep2 = defer.promise
-            let m /* :MessageSyncStep2 */ = message
-            db.requestTransaction(function * () {
-              yield* this.applyDeleteSet(m.deleteSet)
-              if (m.osUntransformed != null) {
-                yield* this.applyOperationsUntransformed(m.osUntransformed, m.stateSet)
-              } else {
-                this.store.apply(m.os)
-              }
-              /*
-               * This just sends the complete hb after some time
-               * Mostly for debugging..
-               *
-              db.requestTransaction(function * () {
-                var ops = yield* this.getOperations(m.stateSet)
-                if (ops.length > 0) {
-                  if (!broadcastHB) { // TODO: consider to broadcast here..
-                    conn.send(sender, {
-                      type: 'update',
-                      ops: ops
-                    })
-                  } else {
-                    // broadcast only once!
-                    conn.broadcastOps(ops)
-                  }
-                }
-              })
-              */
-              defer.resolve()
-            })
-          } else if (message.type === 'sync done') {
-            var self = this
-            this.syncStep2.then(function () {
-              self._setSyncedWith(sender)
-            })
-          } else if (message.type === 'update' && canWrite(auth)) {
-            if (this.forwardToSyncingClients) {
-              for (var client of this.syncingClients) {
-                this.send(client, message)
-              }
-            }
-            if (this.y.db.forwardAppliedOperations) {
-              var delops = message.ops.filter(function (o) {
-                return o.struct === 'Delete'
-              })
-              if (delops.length > 0) {
-                this.broadcastOps(delops)
-              }
-            }
-            this.y.db.apply(message.ops)
-          }
-        })
-      } else {
-        return Promise.reject('Unable to deliver message')
-      }
-    }
-    _setSyncedWith (user) {
-      var conn = this.connections[user]
-      if (conn != null) {
-        conn.isSynced = true
-      }
-      if (user === this.currentSyncTarget) {
-        this.currentSyncTarget = null
-        this.findNextSyncTarget()
-      }
-    }
-    /*
-      Currently, the HB encodes operations as JSON. For the moment I want to keep it
-      that way. Maybe we support encoding in the HB as XML in the future, but for now I don't want
-      too much overhead. Y is very likely to get changed a lot in the future
-
-      Because we don't want to encode JSON as string (with character escaping, wich makes it pretty much unreadable)
-      we encode the JSON as XML.
-
-      When the HB support encoding as XML, the format should look pretty much like this.
-
-      does not support primitive values as array elements
-      expects an ltx (less than xml) object
-    */
-    parseMessageFromXml (m/* :any */) {
-      function parseArray (node) {
-        for (var n of node.children) {
-          if (n.getAttribute('isArray') === 'true') {
-            return parseArray(n)
-          } else {
-            return parseObject(n)
-          }
-        }
-      }
-      function parseObject (node/* :any */) {
-        var json = {}
-        for (var attrName in node.attrs) {
-          var value = node.attrs[attrName]
-          var int = parseInt(value, 10)
-          if (isNaN(int) || ('' + int) !== value) {
-            json[attrName] = value
-          } else {
-            json[attrName] = int
-          }
-        }
-        for (var n/* :any */ in node.children) {
-          var name = n.name
-          if (n.getAttribute('isArray') === 'true') {
-            json[name] = parseArray(n)
-          } else {
-            json[name] = parseObject(n)
-          }
-        }
-        return json
-      }
-      parseObject(m)
-    }
-    /*
-      encode message in xml
-      we use string because Strophe only accepts an "xml-string"..
-      So {a:4,b:{c:5}} will look like
-      <y a="4">
-        <b c="5"></b>
-      </y>
-      m - ltx element
-      json - Object
-    */
-    encodeMessageToXml (msg, obj) {
-      // attributes is optional
-      function encodeObject (m, json) {
-        for (var name in json) {
-          var value = json[name]
-          if (name == null) {
-            // nop
-          } else if (value.constructor === Object) {
-            encodeObject(m.c(name), value)
-          } else if (value.constructor === Array) {
-            encodeArray(m.c(name), value)
-          } else {
-            m.setAttribute(name, value)
-          }
-        }
-      }
-      function encodeArray (m, array) {
-        m.setAttribute('isArray', 'true')
-        for (var e of array) {
-          if (e.constructor === Object) {
-            encodeObject(m.c('array-element'), e)
-          } else {
-            encodeArray(m.c('array-element'), e)
-          }
-        }
-      }
-      if (obj.constructor === Object) {
-        encodeObject(msg.c('y', { xmlns: 'http://y.ninja/connector-stanza' }), obj)
-      } else if (obj.constructor === Array) {
-        encodeArray(msg.c('y', { xmlns: 'http://y.ninja/connector-stanza' }), obj)
-      } else {
-        throw new Error("I can't encode this json!")
-      }
-    }
-  }
-  Y.AbstractConnector = AbstractConnector
-}

src/Connectors/Test.js

@@ -1,178 +0,0 @@
-/* global getRandom, async */
-'use strict'
-
-module.exports = function (Y) {
-  var globalRoom = {
-    users: {},
-    buffers: {},
-    removeUser: function (user) {
-      for (var i in this.users) {
-        this.users[i].userLeft(user)
-      }
-      delete this.users[user]
-      delete this.buffers[user]
-    },
-    addUser: function (connector) {
-      this.users[connector.userId] = connector
-      this.buffers[connector.userId] = {}
-      for (var uname in this.users) {
-        if (uname !== connector.userId) {
-          var u = this.users[uname]
-          u.userJoined(connector.userId, 'master')
-          connector.userJoined(u.userId, 'master')
-        }
-      }
-    },
-    whenTransactionsFinished: function () {
-      var self = this
-      return new Promise(function (resolve, reject) {
-        // The connector first has to send the messages to the db.
-        // Wait for the checkAuth-function to resolve
-        // The test lib only has a simple checkAuth function: `() => Promise.resolve()`
-        // Just add a function to the event-queue, in order to wait for the event.
-        // TODO: this may be buggy in test applications (but it isn't be for real-life apps)
-        setTimeout(function () {
-          var ps = []
-          for (var name in self.users) {
-            ps.push(self.users[name].y.db.whenTransactionsFinished())
-          }
-          Promise.all(ps).then(resolve, reject)
-        }, 10)
-      })
-    },
-    flushOne: function flushOne () {
-      var bufs = []
-      for (var receiver in globalRoom.buffers) {
-        let buff = globalRoom.buffers[receiver]
-        var push = false
-        for (let sender in buff) {
-          if (buff[sender].length > 0) {
-            push = true
-            break
-          }
-        }
-        if (push) {
-          bufs.push(receiver)
-        }
-      }
-      if (bufs.length > 0) {
-        var userId = getRandom(bufs)
-        let buff = globalRoom.buffers[userId]
-        let sender = getRandom(Object.keys(buff))
-        var m = buff[sender].shift()
-        if (buff[sender].length === 0) {
-          delete buff[sender]
-        }
-        var user = globalRoom.users[userId]
-        return user.receiveMessage(m[0], m[1]).then(function () {
-          return user.y.db.whenTransactionsFinished()
-        }, function () {})
-      } else {
-        return false
-      }
-    },
-    flushAll: function () {
-      return new Promise(function (resolve) {
-        // flushes may result in more created operations,
-        // flush until there is nothing more to flush
-        function nextFlush () {
-          var c = globalRoom.flushOne()
-          if (c) {
-            while (c) {
-              c = globalRoom.flushOne()
-            }
-            globalRoom.whenTransactionsFinished().then(nextFlush)
-          } else {
-            c = globalRoom.flushOne()
-            if (c) {
-              c.then(function () {
-                globalRoom.whenTransactionsFinished().then(nextFlush)
-              })
-            } else {
-              resolve()
-            }
-          }
-        }
-        globalRoom.whenTransactionsFinished().then(nextFlush)
-      })
-    }
-  }
-  Y.utils.globalRoom = globalRoom
-
-  var userIdCounter = 0
-
-  class Test extends Y.AbstractConnector {
-    constructor (y, options) {
-      if (options === undefined) {
-        throw new Error('Options must not be undefined!')
-      }
-      options.role = 'master'
-      options.forwardToSyncingClients = false
-      super(y, options)
-      this.setUserId((userIdCounter++) + '').then(() => {
-        globalRoom.addUser(this)
-      })
-      this.globalRoom = globalRoom
-      this.syncingClientDuration = 0
-    }
-    receiveMessage (sender, m) {
-      return super.receiveMessage(sender, JSON.parse(JSON.stringify(m)))
-    }
-    send (userId, message) {
-      var buffer = globalRoom.buffers[userId]
-      if (buffer != null) {
-        if (buffer[this.userId] == null) {
-          buffer[this.userId] = []
-        }
-        buffer[this.userId].push(JSON.parse(JSON.stringify([this.userId, message])))
-      }
-    }
-    broadcast (message) {
-      for (var key in globalRoom.buffers) {
-        var buff = globalRoom.buffers[key]
-        if (buff[this.userId] == null) {
-          buff[this.userId] = []
-        }
-        buff[this.userId].push(JSON.parse(JSON.stringify([this.userId, message])))
-      }
-    }
-    isDisconnected () {
-      return globalRoom.users[this.userId] == null
-    }
-    reconnect () {
-      if (this.isDisconnected()) {
-        globalRoom.addUser(this)
-        super.reconnect()
-      }
-      return Y.utils.globalRoom.flushAll()
-    }
-    disconnect () {
-      var waitForMe = Promise.resolve()
-      if (!this.isDisconnected()) {
-        globalRoom.removeUser(this.userId)
-        waitForMe = super.disconnect()
-      }
-      var self = this
-      return waitForMe.then(function () {
-        return self.y.db.whenTransactionsFinished()
-      })
-    }
-    flush () {
-      var self = this
-      return async(function * () {
-        var buff = globalRoom.buffers[self.userId]
-        while (Object.keys(buff).length > 0) {
-          var sender = getRandom(Object.keys(buff))
-          var m = buff[sender].shift()
-          if (buff[sender].length === 0) {
-            delete buff[sender]
-          }
-          yield this.receiveMessage(m[0], m[1])
-        }
-        yield self.whenTransactionsFinished()
-      })
-    }
-  }
-
-  Y.Test = Test
-}

src/Database.js

@@ -1,604 +0,0 @@
-/* @flow */
-'use strict'
-
-module.exports = function (Y /* :any */) {
-  /*
-    Partial definition of an OperationStore.
-    TODO: name it Database, operation store only holds operations.
-
-    A database definition must alse define the following methods:
-    * logTable() (optional)
-      - show relevant information information in a table
-    * requestTransaction(makeGen)
-      - request a transaction
-    * destroy()
-      - destroy the database
-  */
-  class AbstractDatabase {
-    /* ::
-    y: YConfig;
-    forwardAppliedOperations: boolean;
-    listenersById: Object;
-    listenersByIdExecuteNow: Array<Object>;
-    listenersByIdRequestPending: boolean;
-    initializedTypes: Object;
-    whenUserIdSetListener: ?Function;
-    waitingTransactions: Array<Transaction>;
-    transactionInProgress: boolean;
-    executeOrder: Array<Object>;
-    gc1: Array<Struct>;
-    gc2: Array<Struct>;
-    gcTimeout: number;
-    gcInterval: any;
-    garbageCollect: Function;
-    executeOrder: Array<any>; // for debugging only
-    userId: UserId;
-    opClock: number;
-    transactionsFinished: ?{promise: Promise, resolve: any};
-    transact: (x: ?Generator) => any;
-    */
-    constructor (y, opts) {
-      this.y = y
-      this.dbOpts = opts
-      var os = this
-      this.userId = null
-      var resolve
-      this.userIdPromise = new Promise(function (r) {
-        resolve = r
-      })
-      this.userIdPromise.resolve = resolve
-      // whether to broadcast all applied operations (insert & delete hook)
-      this.forwardAppliedOperations = false
-      // E.g. this.listenersById[id] : Array<Listener>
-      this.listenersById = {}
-      // Execute the next time a transaction is requested
-      this.listenersByIdExecuteNow = []
-      // A transaction is requested
-      this.listenersByIdRequestPending = false
-      /* To make things more clear, the following naming conventions:
-         * ls : we put this.listenersById on ls
-         * l : Array<Listener>
-         * id : Id (can't use as property name)
-         * sid : String (converted from id via JSON.stringify
-                         so we can use it as a property name)
-
-        Always remember to first overwrite
-        a property before you iterate over it!
-      */
-      // TODO: Use ES7 Weak Maps. This way types that are no longer user,
-      // wont be kept in memory.
-      this.initializedTypes = {}
-      this.waitingTransactions = []
-      this.transactionInProgress = false
-      this.transactionIsFlushed = false
-      if (typeof YConcurrency_TestingMode !== 'undefined') {
-        this.executeOrder = []
-      }
-      this.gc1 = [] // first stage
-      this.gc2 = [] // second stage -> after that, remove the op
-
-      function garbageCollect () {
-        return os.whenTransactionsFinished().then(function () {
-          if (os.gc1.length > 0 || os.gc2.length > 0) {
-            if (!os.y.connector.isSynced) {
-              console.warn('gc should be empty when not synced!')
-            }
-            return new Promise((resolve) => {
-              os.requestTransaction(function * () {
-                if (os.y.connector != null && os.y.connector.isSynced) {
-                  for (var i = 0; i < os.gc2.length; i++) {
-                    var oid = os.gc2[i]
-                    yield* this.garbageCollectOperation(oid)
-                  }
-                  os.gc2 = os.gc1
-                  os.gc1 = []
-                }
-                // TODO: Use setInterval here instead (when garbageCollect is called several times there will be several timeouts..)
-                if (os.gcTimeout > 0) {
-                  os.gcInterval = setTimeout(garbageCollect, os.gcTimeout)
-                }
-                resolve()
-              })
-            })
-          } else {
-            // TODO: see above
-            if (os.gcTimeout > 0) {
-              os.gcInterval = setTimeout(garbageCollect, os.gcTimeout)
-            }
-            return Promise.resolve()
-          }
-        })
-      }
-      this.garbageCollect = garbageCollect
-      this.startGarbageCollector()
-
-      this.repairCheckInterval = !opts.repairCheckInterval ? 6000 : opts.repairCheckInterval
-      this.opsReceivedTimestamp = new Date()
-      this.startRepairCheck()
-    }
-    startGarbageCollector () {
-      this.gc = this.dbOpts.gc == null || this.dbOpts.gc
-      if (this.gc) {
-        this.gcTimeout = !this.dbOpts.gcTimeout ? 50000 : this.dbOpts.gcTimeout
-      } else {
-        this.gcTimeout = -1
-      }
-      if (this.gcTimeout > 0) {
-        this.garbageCollect()
-      }
-    }
-    startRepairCheck () {
-      var os = this
-      if (this.repairCheckInterval > 0) {
-        this.repairCheckIntervalHandler = setInterval(function repairOnMissingOperations () {
-          /*
-            Case 1. No ops have been received in a while (new Date() - os.opsReceivedTimestamp > os.repairCheckInterval)
-              - 1.1 os.listenersById is empty. Then the state was correct the whole time. -> Nothing to do (nor to update)
-              - 1.2 os.listenersById is not empty.
-                      * Then the state was incorrect for at least {os.repairCheckInterval} seconds.
-                      * -> Remove everything in os.listenersById and sync again (connector.repair())
-            Case 2. An op has been received in the last {os.repairCheckInterval } seconds.
-                    It is not yet necessary to check for faulty behavior. Everything can still resolve itself. Wait for more messages.
-                    If nothing was received for a while and os.listenersById is still not emty, we are in case 1.2
-                    -> Do nothing
-
-            Baseline here is: we really only have to catch case 1.2..
-          */
-          if (
-            new Date() - os.opsReceivedTimestamp > os.repairCheckInterval &&
-            Object.keys(os.listenersById).length > 0 // os.listenersById is not empty
-          ) {
-            // haven't received operations for over {os.repairCheckInterval} seconds, resend state vector
-            os.listenersById = {}
-            os.opsReceivedTimestamp = new Date() // update so you don't send repair several times in a row
-            os.y.connector.repair()
-          }
-        }, this.repairCheckInterval)
-      }
-    }
-    stopRepairCheck () {
-      clearInterval(this.repairCheckIntervalHandler)
-    }
-    queueGarbageCollector (id) {
-      if (this.y.connector.isSynced && this.gc) {
-        this.gc1.push(id)
-      }
-    }
-    emptyGarbageCollector () {
-      return new Promise(resolve => {
-        var check = () => {
-          if (this.gc1.length > 0 || this.gc2.length > 0) {
-            this.garbageCollect().then(check)
-          } else {
-            resolve()
-          }
-        }
-        setTimeout(check, 0)
-      })
-    }
-    addToDebug () {
-      if (typeof YConcurrency_TestingMode !== 'undefined') {
-        var command /* :string */ = Array.prototype.map.call(arguments, function (s) {
-          if (typeof s === 'string') {
-            return s
-          } else {
-            return JSON.stringify(s)
-          }
-        }).join('').replace(/"/g, "'").replace(/,/g, ', ').replace(/:/g, ': ')
-        this.executeOrder.push(command)
-      }
-    }
-    getDebugData () {
-      console.log(this.executeOrder.join('\n'))
-    }
-    stopGarbageCollector () {
-      var self = this
-      this.gc = false
-      this.gcTimeout = -1
-      return new Promise(function (resolve) {
-        self.requestTransaction(function * () {
-          var ungc /* :Array<Struct> */ = self.gc1.concat(self.gc2)
-          self.gc1 = []
-          self.gc2 = []
-          for (var i = 0; i < ungc.length; i++) {
-            var op = yield* this.getOperation(ungc[i])
-            if (op != null) {
-              delete op.gc
-              yield* this.setOperation(op)
-            }
-          }
-          resolve()
-        })
-      })
-    }
-    /*
-      Try to add to GC.
-
-      TODO: rename this function
-
-      Rulez:
-      * Only gc if this user is online & gc turned on
-      * The most left element in a list must not be gc'd.
-        => There is at least one element in the list
-
-      returns true iff op was added to GC
-    */
-    * addToGarbageCollector (op, left) {
-      if (
-        op.gc == null &&
-        op.deleted === true &&
-        this.store.gc &&
-        this.store.y.connector.isSynced
-      ) {
-        var gc = false
-        if (left != null && left.deleted === true) {
-          gc = true
-        } else if (op.content != null && op.content.length > 1) {
-          op = yield* this.getInsertionCleanStart([op.id[0], op.id[1] + 1])
-          gc = true
-        }
-        if (gc) {
-          op.gc = true
-          yield* this.setOperation(op)
-          this.store.queueGarbageCollector(op.id)
-          return true
-        }
-      }
-      return false
-    }
-    removeFromGarbageCollector (op) {
-      function filter (o) {
-        return !Y.utils.compareIds(o, op.id)
-      }
-      this.gc1 = this.gc1.filter(filter)
-      this.gc2 = this.gc2.filter(filter)
-      delete op.gc
-    }
-    destroyTypes () {
-      for (var key in this.initializedTypes) {
-        var type = this.initializedTypes[key]
-        if (type._destroy != null) {
-          type._destroy()
-        } else {
-          console.error('The type you included does not provide destroy functionality, it will remain in memory (updating your packages will help).')
-        }
-      }
-    }
-    * destroy () {
-      clearInterval(this.gcInterval)
-      this.gcInterval = null
-      this.stopRepairCheck()
-    }
-    setUserId (userId) {
-      if (!this.userIdPromise.inProgress) {
-        this.userIdPromise.inProgress = true
-        var self = this
-        self.requestTransaction(function * () {
-          self.userId = userId
-          var state = yield* this.getState(userId)
-          self.opClock = state.clock
-          self.userIdPromise.resolve(userId)
-        })
-      }
-      return this.userIdPromise
-    }
-    whenUserIdSet (f) {
-      this.userIdPromise.then(f)
-    }
-    getNextOpId (numberOfIds) {
-      if (numberOfIds == null) {
-        throw new Error('getNextOpId expects the number of created ids to create!')
-      } else if (this.userId == null) {
-        throw new Error('OperationStore not yet initialized!')
-      } else {
-        var id = [this.userId, this.opClock]
-        this.opClock += numberOfIds
-        return id
-      }
-    }
-    /*
-      Apply a list of operations.
-
-      * we save a timestamp, because we received new operations that could resolve ops in this.listenersById (see this.startRepairCheck)
-      * get a transaction
-      * check whether all Struct.*.requiredOps are in the OS
-      * check if it is an expected op (otherwise wait for it)
-      * check if was deleted, apply a delete operation after op was applied
-    */
-    apply (ops) {
-      this.opsReceivedTimestamp = new Date()
-      for (var i = 0; i < ops.length; i++) {
-        var o = ops[i]
-        if (o.id == null || o.id[0] !== this.y.connector.userId) {
-          var required = Y.Struct[o.struct].requiredOps(o)
-          if (o.requires != null) {
-            required = required.concat(o.requires)
-          }
-          this.whenOperationsExist(required, o)
-        }
-      }
-    }
-    /*
-      op is executed as soon as every operation requested is available.
-      Note that Transaction can (and should) buffer requests.
-    */
-    whenOperationsExist (ids, op) {
-      if (ids.length > 0) {
-        let listener = {
-          op: op,
-          missing: ids.length
-        }
-
-        for (let i = 0; i < ids.length; i++) {
-          let id = ids[i]
-          let sid = JSON.stringify(id)
-          let l = this.listenersById[sid]
-          if (l == null) {
-            l = []
-            this.listenersById[sid] = l
-          }
-          l.push(listener)
-        }
-      } else {
-        this.listenersByIdExecuteNow.push({
-          op: op
-        })
-      }
-
-      if (this.listenersByIdRequestPending) {
-        return
-      }
-
-      this.listenersByIdRequestPending = true
-      var store = this
-
-      this.requestTransaction(function * () {
-        var exeNow = store.listenersByIdExecuteNow
-        store.listenersByIdExecuteNow = []
-
-        var ls = store.listenersById
-        store.listenersById = {}
-
-        store.listenersByIdRequestPending = false
-
-        for (let key = 0; key < exeNow.length; key++) {
-          let o = exeNow[key].op
-          yield* store.tryExecute.call(this, o)
-        }
-
-        for (var sid in ls) {
-          var l = ls[sid]
-          var id = JSON.parse(sid)
-          var op
-          if (typeof id[1] === 'string') {
-            op = yield* this.getOperation(id)
-          } else {
-            op = yield* this.getInsertion(id)
-          }
-          if (op == null) {
-            store.listenersById[sid] = l
-          } else {
-            for (let i = 0; i < l.length; i++) {
-              let listener = l[i]
-              let o = listener.op
-              if (--listener.missing === 0) {
-                yield* store.tryExecute.call(this, o)
-              }
-            }
-          }
-        }
-      })
-    }
-    /*
-      Actually execute an operation, when all expected operations are available.
-    */
-    /* :: // TODO: this belongs somehow to transaction
-    store: Object;
-    getOperation: any;
-    isGarbageCollected: any;
-    addOperation: any;
-    whenOperationsExist: any;
-    */
-    * tryExecute (op) {
-      this.store.addToDebug('yield* this.store.tryExecute.call(this, ', JSON.stringify(op), ')')
-      if (op.struct === 'Delete') {
-        yield* Y.Struct.Delete.execute.call(this, op)
-        // this is now called in Transaction.deleteOperation!
-        // yield* this.store.operationAdded(this, op)
-      } else {
-        // check if this op was defined
-        var defined = yield* this.getInsertion(op.id)
-        while (defined != null && defined.content != null) {
-          // check if this op has a longer content in the case it is defined
-          if (defined.id[1] + defined.content.length < op.id[1] + op.content.length) {
-            var overlapSize = defined.content.length - (op.id[1] - defined.id[1])
-            op.content.splice(0, overlapSize)
-            op.id = [op.id[0], op.id[1] + overlapSize]
-            op.left = Y.utils.getLastId(defined)
-            op.origin = op.left
-            defined = yield* this.getOperation(op.id) // getOperation suffices here
-          } else {
-            break
-          }
-        }
-        if (defined == null) {
-          var opid = op.id
-          var isGarbageCollected = yield* this.isGarbageCollected(opid)
-          if (!isGarbageCollected) {
-            // TODO: reduce number of get / put calls for op ..
-            yield* Y.Struct[op.struct].execute.call(this, op)
-            yield* this.addOperation(op)
-            yield* this.store.operationAdded(this, op)
-            // operationAdded can change op..
-            op = yield* this.getOperation(opid)
-            // if insertion, try to combine with left
-            yield* this.tryCombineWithLeft(op)
-          }
-        }
-      }
-    }
-    /*
-     * Called by a transaction when an operation is added.
-     * This function is especially important for y-indexeddb, where several instances may share a single database.
-     * Every time an operation is created by one instance, it is send to all other instances and operationAdded is called
-     *
-     * If it's not a Delete operation:
-     *   * Checks if another operation is executable (listenersById)
-     *   * Update state, if possible
-     *
-     * Always:
-     *   * Call type
-     */
-    * operationAdded (transaction, op) {
-      if (op.struct === 'Delete') {
-        var type = this.initializedTypes[JSON.stringify(op.targetParent)]
-        if (type != null) {
-          yield* type._changed(transaction, op)
-        }
-      } else {
-        // increase SS
-        yield* transaction.updateState(op.id[0])
-        var opLen = op.content != null ? op.content.length : 1
-        for (let i = 0; i < opLen; i++) {
-          // notify whenOperation listeners (by id)
-          var sid = JSON.stringify([op.id[0], op.id[1] + i])
-          var l = this.listenersById[sid]
-          delete this.listenersById[sid]
-          if (l != null) {
-            for (var key in l) {
-              var listener = l[key]
-              if (--listener.missing === 0) {
-                this.whenOperationsExist([], listener.op)
-              }
-            }
-          }
-        }
-        var t = this.initializedTypes[JSON.stringify(op.parent)]
-
-        // if parent is deleted, mark as gc'd and return
-        if (op.parent != null) {
-          var parentIsDeleted = yield* transaction.isDeleted(op.parent)
-          if (parentIsDeleted) {
-            yield* transaction.deleteList(op.id)
-            return
-          }
-        }
-
-        // notify parent, if it was instanciated as a custom type
-        if (t != null) {
-          let o = Y.utils.copyOperation(op)
-          yield* t._changed(transaction, o)
-        }
-        if (!op.deleted) {
-          // Delete if DS says this is actually deleted
-          var len = op.content != null ? op.content.length : 1
-          var startId = op.id // You must not use op.id in the following loop, because op will change when deleted
-            // TODO: !! console.log('TODO: change this before commiting')
-          for (let i = 0; i < len; i++) {
-            var id = [startId[0], startId[1] + i]
-            var opIsDeleted = yield* transaction.isDeleted(id)
-            if (opIsDeleted) {
-              var delop = {
-                struct: 'Delete',
-                target: id
-              }
-              yield* this.tryExecute.call(transaction, delop)
-            }
-          }
-        }
-      }
-    }
-    whenTransactionsFinished () {
-      if (this.transactionInProgress) {
-        if (this.transactionsFinished == null) {
-          var resolve
-          var promise = new Promise(function (r) {
-            resolve = r
-          })
-          this.transactionsFinished = {
-            resolve: resolve,
-            promise: promise
-          }
-        }
-        return this.transactionsFinished.promise
-      } else {
-        return Promise.resolve()
-      }
-    }
-    // Check if there is another transaction request.
-    // * the last transaction is always a flush :)
-    getNextRequest () {
-      if (this.waitingTransactions.length === 0) {
-        if (this.transactionIsFlushed) {
-          this.transactionInProgress = false
-          this.transactionIsFlushed = false
-          if (this.transactionsFinished != null) {
-            this.transactionsFinished.resolve()
-            this.transactionsFinished = null
-          }
-          return null
-        } else {
-          this.transactionIsFlushed = true
-          return function * () {
-            yield* this.flush()
-          }
-        }
-      } else {
-        this.transactionIsFlushed = false
-        return this.waitingTransactions.shift()
-      }
-    }
-    requestTransaction (makeGen/* :any */, callImmediately) {
-      this.waitingTransactions.push(makeGen)
-      if (!this.transactionInProgress) {
-        this.transactionInProgress = true
-        setTimeout(() => {
-          this.transact(this.getNextRequest())
-        }, 0)
-      }
-    }
-    /*
-      Get a created/initialized type.
-    */
-    getType (id) {
-      return this.initializedTypes[JSON.stringify(id)]
-    }
-    /*
-      Init type. This is called when a remote operation is retrieved, and transformed to a type
-      TODO: delete type from store.initializedTypes[id] when corresponding id was deleted!
-    */
-    * initType (id, args) {
-      var sid = JSON.stringify(id)
-      var t = this.store.initializedTypes[sid]
-      if (t == null) {
-        var op/* :MapStruct | ListStruct */ = yield* this.getOperation(id)
-        if (op != null) {
-          t = yield* Y[op.type].typeDefinition.initType.call(this, this.store, op, args)
-          this.store.initializedTypes[sid] = t
-        }
-      }
-      return t
-    }
-    /*
-     Create type. This is called when the local user creates a type (which is a synchronous action)
-    */
-    createType (typedefinition, id) {
-      var structname = typedefinition[0].struct
-      id = id || this.getNextOpId(1)
-      var op = Y.Struct[structname].create(id)
-      op.type = typedefinition[0].name
-
-      this.requestTransaction(function * () {
-        if (op.id[0] === '_') {
-          yield* this.setOperation(op)
-        } else {
-          yield* this.applyCreatedOperations([op])
-        }
-      })
-      var t = Y[op.type].typeDefinition.createType(this, op, typedefinition[1])
-      this.initializedTypes[JSON.stringify(op.id)] = t
-      return t
-    }
-  }
-  Y.AbstractDatabase = AbstractDatabase
-}

src/Database.spec.js

@@ -1,354 +0,0 @@
-/* global async, databases, describe, beforeEach, afterEach */
-/* eslint-env browser,jasmine,console */
-'use strict'
-
-var Y = require('./SpecHelper.js')
-
-for (let database of databases) {
-  describe(`Database (${database})`, function () {
-    var store
-    describe('DeleteStore', function () {
-      describe('Basic', function () {
-        beforeEach(function () {
-          store = new Y[database](null, {
-            gcTimeout: -1,
-            namespace: 'testing'
-          })
-        })
-        afterEach(function (done) {
-          store.requestTransaction(function * () {
-            yield* this.store.destroy()
-            done()
-          })
-        })
-        it('Deleted operation is deleted', async(function * (done) {
-          store.requestTransaction(function * () {
-            yield* this.markDeleted(['u1', 10], 1)
-            expect(yield* this.isDeleted(['u1', 10])).toBeTruthy()
-            expect(yield* this.getDeleteSet()).toEqual({'u1': [[10, 1, false]]})
-            done()
-          })
-        }))
-        it('Deleted operation extends other deleted operation', async(function * (done) {
-          store.requestTransaction(function * () {
-            yield* this.markDeleted(['u1', 10], 1)
-            yield* this.markDeleted(['u1', 11], 1)
-            expect(yield* this.isDeleted(['u1', 10])).toBeTruthy()
-            expect(yield* this.isDeleted(['u1', 11])).toBeTruthy()
-            expect(yield* this.getDeleteSet()).toEqual({'u1': [[10, 2, false]]})
-            done()
-          })
-        }))
-        it('Deleted operation extends other deleted operation', async(function * (done) {
-          store.requestTransaction(function * () {
-            yield* this.markDeleted(['0', 3], 1)
-            yield* this.markDeleted(['0', 4], 1)
-            yield* this.markDeleted(['0', 2], 1)
-            expect(yield* this.getDeleteSet()).toEqual({'0': [[2, 3, false]]})
-            done()
-          })
-        }))
-        it('Debug #1', async(function * (done) {
-          store.requestTransaction(function * () {
-            yield* this.markDeleted(['166', 0], 1)
-            yield* this.markDeleted(['166', 2], 1)
-            yield* this.markDeleted(['166', 0], 1)
-            yield* this.markDeleted(['166', 2], 1)
-            yield* this.markGarbageCollected(['166', 2], 1)
-            yield* this.markDeleted(['166', 1], 1)
-            yield* this.markDeleted(['166', 3], 1)
-            yield* this.markGarbageCollected(['166', 3], 1)
-            yield* this.markDeleted(['166', 0], 1)
-            expect(yield* this.getDeleteSet()).toEqual({'166': [[0, 2, false], [2, 2, true]]})
-            done()
-          })
-        }))
-        it('Debug #2', async(function * (done) {
-          store.requestTransaction(function * () {
-            yield* this.markDeleted(['293', 0], 1)
-            yield* this.markDeleted(['291', 2], 1)
-            yield* this.markDeleted(['291', 2], 1)
-            yield* this.markGarbageCollected(['293', 0], 1)
-            yield* this.markDeleted(['293', 1], 1)
-            yield* this.markGarbageCollected(['291', 2], 1)
-            expect(yield* this.getDeleteSet()).toEqual({'291': [[2, 1, true]], '293': [[0, 1, true], [1, 1, false]]})
-            done()
-          })
-        }))
-        it('Debug #3', async(function * (done) {
-          store.requestTransaction(function * () {
-            yield* this.markDeleted(['581', 0], 1)
-            yield* this.markDeleted(['581', 1], 1)
-            yield* this.markDeleted(['580', 0], 1)
-            yield* this.markDeleted(['580', 0], 1)
-            yield* this.markGarbageCollected(['581', 0], 1)
-            yield* this.markDeleted(['581', 2], 1)
-            yield* this.markDeleted(['580', 1], 1)
-            yield* this.markDeleted(['580', 2], 1)
-            yield* this.markDeleted(['580', 1], 1)
-            yield* this.markDeleted(['580', 2], 1)
-            yield* this.markGarbageCollected(['581', 2], 1)
-            yield* this.markGarbageCollected(['581', 1], 1)
-            yield* this.markGarbageCollected(['580', 1], 1)
-            expect(yield* this.getDeleteSet()).toEqual({'580': [[0, 1, false], [1, 1, true], [2, 1, false]], '581': [[0, 3, true]]})
-            done()
-          })
-        }))
-        it('Debug #4', async(function * (done) {
-          store.requestTransaction(function * () {
-            yield* this.markDeleted(['544', 0], 1)
-            yield* this.markDeleted(['543', 2], 1)
-            yield* this.markDeleted(['544', 0], 1)
-            yield* this.markDeleted(['543', 2], 1)
-            yield* this.markGarbageCollected(['544', 0], 1)
-            yield* this.markDeleted(['545', 1], 1)
-            yield* this.markDeleted(['543', 4], 1)
-            yield* this.markDeleted(['543', 3], 1)
-            yield* this.markDeleted(['544', 1], 1)
-            yield* this.markDeleted(['544', 2], 1)
-            yield* this.markDeleted(['544', 1], 1)
-            yield* this.markDeleted(['544', 2], 1)
-            yield* this.markGarbageCollected(['543', 2], 1)
-            yield* this.markGarbageCollected(['543', 4], 1)
-            yield* this.markGarbageCollected(['544', 2], 1)
-            yield* this.markGarbageCollected(['543', 3], 1)
-            expect(yield* this.getDeleteSet()).toEqual({'543': [[2, 3, true]], '544': [[0, 1, true], [1, 1, false], [2, 1, true]], '545': [[1, 1, false]]})
-            done()
-          })
-        }))
-        it('Debug #5', async(function * (done) {
-          store.requestTransaction(function * () {
-            yield* this.applyDeleteSet({'16': [[1, 2, false]], '17': [[0, 1, true], [1, 3, false]]})
-            expect(yield* this.getDeleteSet()).toEqual({'16': [[1, 2, false]], '17': [[0, 1, true], [1, 3, false]]})
-            yield* this.applyDeleteSet({'16': [[1, 2, false]], '17': [[0, 4, true]]})
-            expect(yield* this.getDeleteSet()).toEqual({'16': [[1, 2, false]], '17': [[0, 4, true]]})
-            done()
-          })
-        }))
-        it('Debug #6', async(function * (done) {
-          store.requestTransaction(function * () {
-            yield* this.applyDeleteSet({'40': [[0, 3, false]]})
-            expect(yield* this.getDeleteSet()).toEqual({'40': [[0, 3, false]]})
-            yield* this.applyDeleteSet({'39': [[2, 2, false]], '40': [[0, 1, true], [1, 2, false]], '41': [[2, 1, false]]})
-            expect(yield* this.getDeleteSet()).toEqual({'39': [[2, 2, false]], '40': [[0, 1, true], [1, 2, false]], '41': [[2, 1, false]]})
-            done()
-          })
-        }))
-        it('Debug #7', async(function * (done) {
-          store.requestTransaction(function * () {
-            yield* this.markDeleted(['9', 2], 1)
-            yield* this.markDeleted(['11', 2], 1)
-            yield* this.markDeleted(['11', 4], 1)
-            yield* this.markDeleted(['11', 1], 1)
-            yield* this.markDeleted(['9', 4], 1)
-            yield* this.markDeleted(['10', 0], 1)
-            yield* this.markGarbageCollected(['11', 2], 1)
-            yield* this.markDeleted(['11', 2], 1)
-            yield* this.markGarbageCollected(['11', 3], 1)
-            yield* this.markDeleted(['11', 3], 1)
-            yield* this.markDeleted(['11', 3], 1)
-            yield* this.markDeleted(['9', 4], 1)
-            yield* this.markDeleted(['10', 0], 1)
-            yield* this.markGarbageCollected(['11', 1], 1)
-            yield* this.markDeleted(['11', 1], 1)
-            expect(yield* this.getDeleteSet()).toEqual({'9': [[2, 1, false], [4, 1, false]], '10': [[0, 1, false]], '11': [[1, 3, true], [4, 1, false]]})
-            done()
-          })
-        }))
-      })
-    })
-    describe('OperationStore', function () {
-      describe('Basic Tests', function () {
-        beforeEach(function () {
-          store = new Y[database](null, {
-            gcTimeout: -1,
-            namespace: 'testing'
-          })
-        })
-        afterEach(function (done) {
-          store.requestTransaction(function * () {
-            yield* this.store.destroy()
-            done()
-          })
-        })
-        it('debug #1', function (done) {
-          store.requestTransaction(function * () {
-            yield* this.os.put({id: [2]})
-            yield* this.os.put({id: [0]})
-            yield* this.os.delete([2])
-            yield* this.os.put({id: [1]})
-            expect(yield* this.os.find([0])).toBeTruthy()
-            expect(yield* this.os.find([1])).toBeTruthy()
-            expect(yield* this.os.find([2])).toBeFalsy()
-            done()
-          })
-        })
-        it('can add&retrieve 5 elements', function (done) {
-          store.requestTransaction(function * () {
-            yield* this.os.put({val: 'four', id: [4]})
-            yield* this.os.put({val: 'one', id: [1]})
-            yield* this.os.put({val: 'three', id: [3]})
-            yield* this.os.put({val: 'two', id: [2]})
-            yield* this.os.put({val: 'five', id: [5]})
-            expect((yield* this.os.find([1])).val).toEqual('one')
-            expect((yield* this.os.find([2])).val).toEqual('two')
-            expect((yield* this.os.find([3])).val).toEqual('three')
-            expect((yield* this.os.find([4])).val).toEqual('four')
-            expect((yield* this.os.find([5])).val).toEqual('five')
-            done()
-          })
-        })
-        it('5 elements do not exist anymore after deleting them', function (done) {
-          store.requestTransaction(function * () {
-            yield* this.os.put({val: 'four', id: [4]})
-            yield* this.os.put({val: 'one', id: [1]})
-            yield* this.os.put({val: 'three', id: [3]})
-            yield* this.os.put({val: 'two', id: [2]})
-            yield* this.os.put({val: 'five', id: [5]})
-            yield* this.os.delete([4])
-            expect(yield* this.os.find([4])).not.toBeTruthy()
-            yield* this.os.delete([3])
-            expect(yield* this.os.find([3])).not.toBeTruthy()
-            yield* this.os.delete([2])
-            expect(yield* this.os.find([2])).not.toBeTruthy()
-            yield* this.os.delete([1])
-            expect(yield* this.os.find([1])).not.toBeTruthy()
-            yield* this.os.delete([5])
-            expect(yield* this.os.find([5])).not.toBeTruthy()
-            done()
-          })
-        })
-      })
-      var numberOfOSTests = 1000
-      describe(`Random Tests - after adding&deleting (0.8/0.2) ${numberOfOSTests} times`, function () {
-        var elements = []
-        beforeAll(function (done) {
-          store = new Y[database](null, {
-            gcTimeout: -1,
-            namespace: 'testing'
-          })
-          store.requestTransaction(function * () {
-            for (var i = 0; i < numberOfOSTests; i++) {
-              var r = Math.random()
-              if (r < 0.8) {
-                var obj = [Math.floor(Math.random() * numberOfOSTests * 10000)]
-                if (!(yield* this.os.find(obj))) {
-                  elements.push(obj)
-                  yield* this.os.put({id: obj})
-                }
-              } else if (elements.length > 0) {
-                var elemid = Math.floor(Math.random() * elements.length)
-                var elem = elements[elemid]
-                elements = elements.filter(function (e) {
-                  return !Y.utils.compareIds(e, elem)
-                })
-                yield* this.os.delete(elem)
-              }
-            }
-            done()
-          })
-        })
-        afterAll(function (done) {
-          store.requestTransaction(function * () {
-            yield* this.store.destroy()
-            done()
-          })
-        })
-        it('can find every object', function (done) {
-          store.requestTransaction(function * () {
-            for (var id of elements) {
-              expect((yield* this.os.find(id)).id).toEqual(id)
-            }
-            done()
-          })
-        })
-
-        it('can find every object with lower bound search', function (done) {
-          store.requestTransaction(function * () {
-            for (var id of elements) {
-              var e = yield* this.os.findWithLowerBound(id)
-              expect(e.id).toEqual(id)
-            }
-            done()
-          })
-        })
-
-        it('iterating over a tree with lower bound yields the right amount of results', function (done) {
-          var lowerBound = elements[Math.floor(Math.random() * elements.length)]
-          var expectedResults = elements.filter(function (e, pos) {
-            return (Y.utils.smaller(lowerBound, e) || Y.utils.compareIds(e, lowerBound)) && elements.indexOf(e) === pos
-          }).length
-
-          var actualResults = 0
-          store.requestTransaction(function * () {
-            yield* this.os.iterate(this, lowerBound, null, function * (val) {
-              expect(val).toBeDefined()
-              actualResults++
-            })
-            expect(expectedResults).toEqual(actualResults)
-            done()
-          })
-        })
-
-        it('iterating over a tree without bounds yield the right amount of results', function (done) {
-          var lowerBound = null
-          var expectedResults = elements.filter(function (e, pos) {
-            return elements.indexOf(e) === pos
-          }).length
-          var actualResults = 0
-          store.requestTransaction(function * () {
-            yield* this.os.iterate(this, lowerBound, null, function * (val) {
-              expect(val).toBeDefined()
-              actualResults++
-            })
-            expect(expectedResults).toEqual(actualResults)
-            done()
-          })
-        })
-
-        it('iterating over a tree with upper bound yields the right amount of results', function (done) {
-          var upperBound = elements[Math.floor(Math.random() * elements.length)]
-          var expectedResults = elements.filter(function (e, pos) {
-            return (Y.utils.smaller(e, upperBound) || Y.utils.compareIds(e, upperBound)) && elements.indexOf(e) === pos
-          }).length
-
-          var actualResults = 0
-          store.requestTransaction(function * () {
-            yield* this.os.iterate(this, null, upperBound, function * (val) {
-              expect(val).toBeDefined()
-              actualResults++
-            })
-            expect(expectedResults).toEqual(actualResults)
-            done()
-          })
-        })
-
-        it('iterating over a tree with upper and lower bounds yield the right amount of results', function (done) {
-          var b1 = elements[Math.floor(Math.random() * elements.length)]
-          var b2 = elements[Math.floor(Math.random() * elements.length)]
-          var upperBound, lowerBound
-          if (Y.utils.smaller(b1, b2)) {
-            lowerBound = b1
-            upperBound = b2
-          } else {
-            lowerBound = b2
-            upperBound = b1
-          }
-          var expectedResults = elements.filter(function (e, pos) {
-            return (Y.utils.smaller(lowerBound, e) || Y.utils.compareIds(e, lowerBound)) &&
-              (Y.utils.smaller(e, upperBound) || Y.utils.compareIds(e, upperBound)) && elements.indexOf(e) === pos
-          }).length
-          var actualResults = 0
-          store.requestTransaction(function * () {
-            yield* this.os.iterate(this, lowerBound, upperBound, function * (val) {
-              expect(val).toBeDefined()
-              actualResults++
-            })
-            expect(expectedResults).toEqual(actualResults)
-            done()
-          })
-        })
-      })
-    })
-  })
-}

src/Notes.md

@@ -1,12 +0,0 @@
-
-# Notes
-
-### Terminology
-
-* DB: DataBase that holds all the information of the shared object. It is devided into the OS, DS, and SS. This can be a persistent database or an in-memory database. Depending on the type of database, it could make sense to store OS, DS, and SS in different tables, or maybe different databases.
-* OS: OperationStore holds all the operations. An operation is a js object with a fixed number of name fields.
-* DS: DeleteStore holds the information about which operations are deleted and which operations were garbage collected (no longer available in the OS).
-* SS: StateSet holds the current state of the OS. SS.getState(username) refers to the amount of operations that were received by that respective user.
-* Op: Operation defines an action on a shared type. But it is also the format in which we store the model of a type. This is why it is also called a Struct/Structure.
-* Type and Structure: We crearly distinguish between type and structure. Short explanation: A type (e.g. Strings, Numbers) have a number of functions that you can apply on them. (+) is well defined on both of them. They are *modeled* by a structure - the functions really change the structure of a type. Types can be implemented differently but still provide the same functionality. In Yjs, almost all types are realized as a doubly linked list (on which Yjs can provide eventual convergence)
-*

src/SpecHelper.js

@@ -1,404 +0,0 @@
-/* eslint-env browser, jasmine */
-
-/*
-  This is just a compilation of functions that help to test this library!
-*/
-
-// When testing, you store everything on the global object. We call it g
-
-var Y = require('./y.js')
-require('../../y-memory/src/Memory.js')(Y)
-require('../../y-array/src/Array.js')(Y)
-require('../../y-map/src/Map.js')(Y)
-require('../../y-indexeddb/src/IndexedDB.js')(Y)
-
-module.exports = Y
-
-var g
-if (typeof global !== 'undefined') {
-  g = global
-} else if (typeof window !== 'undefined') {
-  g = window
-} else {
-  throw new Error('No global object?')
-}
-g.g = g
-
-// Helper methods for the random number generator
-Math.seedrandom = require('seedrandom')
-
-g.generateRandomSeed = function generateRandomSeed () {
-  var seed
-  if (typeof window !== 'undefined' && window.location.hash.length > 1) {
-    seed = window.location.hash.slice(1) // first character is the hash!
-    console.warn('Using random seed that was specified in the url!')
-  } else {
-    seed = JSON.stringify(Math.random())
-  }
-  console.info('Using random seed: ' + seed)
-  g.setRandomSeed(seed)
-}
-
-g.setRandomSeed = function setRandomSeed (seed) {
-  Math.seedrandom.currentSeed = seed
-  Math.seedrandom(Math.seedrandom.currentSeed, { global: true })
-}
-
-g.generateRandomSeed()
-
-g.YConcurrency_TestingMode = true
-
-jasmine.DEFAULT_TIMEOUT_INTERVAL = 200000
-
-g.describeManyTimes = function describeManyTimes (times, name, f) {
-  for (var i = 0; i < times; i++) {
-    describe(name, f)
-  }
-}
-
-/*
-  Wait for a specified amount of time (in ms). defaults to 5ms
-*/
-function wait (t) {
-  if (t == null) {
-    t = 0
-  }
-  return new Promise(function (resolve) {
-    setTimeout(function () {
-      resolve()
-    }, t)
-  })
-}
-g.wait = wait
-
-g.databases = ['memory']
-if (typeof window !== 'undefined') {
-  g.databases.push('indexeddb')
-} else {
-  g.databases.push('leveldb')
-}
-/*
-  returns a random element of o.
-  works on Object, and Array
-*/
-function getRandom (o) {
-  if (o instanceof Array) {
-    return o[Math.floor(Math.random() * o.length)]
-  } else if (o.constructor === Object) {
-    return o[getRandom(Object.keys(o))]
-  }
-}
-g.getRandom = getRandom
-
-function getRandomNumber (n) {
-  if (n == null) {
-    n = 9999
-  }
-  return Math.floor(Math.random() * n)
-}
-g.getRandomNumber = getRandomNumber
-
-function getRandomString () {
-  var chars = 'abcdefghijklmnopqrstuvwxyzäüöABCDEFGHIJKLMNOPQRSTUVWXYZÄÜÖ'
-  var char = chars[getRandomNumber(chars.length)] // ü\n\n\n\n\n\n\n'
-  var length = getRandomNumber(7)
-  var string = ''
-  for (var i = 0; i < length; i++) {
-    string += char
-  }
-  return string
-}
-g.getRandomString = getRandomString
-
-function * applyTransactions (relAmount, numberOfTransactions, objects, users, transactions, noReconnect) {
-  g.generateRandomSeed() // create a new seed, so we can re-create the behavior
-  for (var i = 0; i < numberOfTransactions * relAmount + 1; i++) {
-    var r = Math.random()
-    if (r > 0.95) {
-      // 10% chance of toggling concurrent user interactions.
-      // There will be an artificial delay until ops can be executed by the type,
-      // therefore, operations of the database will be (pre)transformed until user operations arrive
-      yield (function simulateConcurrentUserInteractions (type) {
-        if (!(type instanceof Y.utils.CustomType) && type.y instanceof Y.utils.CustomType) {
-          // usually we expect type to be a custom type. But in YXml we share an object {y: YXml, dom: Dom} instead
-          type = type.y
-        }
-        if (type.eventHandler.awaiting === 0 && type.eventHandler._debuggingAwaiting !== true) {
-          type.eventHandler.awaiting = 1
-          type.eventHandler._debuggingAwaiting = true
-        } else {
-          // fixAwaitingInType will handle _debuggingAwaiting
-          return fixAwaitingInType(type)
-        }
-      })(getRandom(objects))
-    } else if (r >= 0.5) {
-      // 40% chance to flush
-      yield Y.utils.globalRoom.flushOne() // flushes for some user.. (not necessarily 0)
-    } else if (noReconnect || r >= 0.05) {
-      // 45% chance to create operation
-      var done = getRandom(transactions)(getRandom(objects))
-      if (done != null) {
-        yield done
-      } else {
-        yield wait()
-      }
-      yield Y.utils.globalRoom.whenTransactionsFinished()
-    } else {
-      // 5% chance to disconnect/reconnect
-      var u = getRandom(users)
-      yield Promise.all(objects.map(fixAwaitingInType))
-      if (u.connector.isDisconnected()) {
-        yield u.reconnect()
-      } else {
-        yield u.disconnect()
-      }
-      yield Promise.all(objects.map(fixAwaitingInType))
-    }
-  }
-}
-
-function fixAwaitingInType (type) {
-  if (!(type instanceof Y.utils.CustomType) && type.y instanceof Y.utils.CustomType) {
-    // usually we expect type to be a custom type. But in YXml we share an object {y: YXml, dom: Dom} instead
-    type = type.y
-  }
-  return new Promise(function (resolve) {
-    type.os.whenTransactionsFinished().then(function () {
-      // _debuggingAwaiting artificially increases the awaiting property. We need to make sure that we only do that once / reverse the effect once
-      type.os.requestTransaction(function * () {
-        if (type.eventHandler.awaiting > 0 && type.eventHandler._debuggingAwaiting === true) {
-          type.eventHandler._debuggingAwaiting = false
-          yield* type.eventHandler.awaitOps(this, function * () { /* mock function */ })
-        }
-        wait(50).then(type.os.whenTransactionsFinished()).then(wait(50)).then(resolve)
-      })
-    })
-  })
-}
-g.fixAwaitingInType = fixAwaitingInType
-
-g.applyRandomTransactionsNoGCNoDisconnect = async(function * applyRandomTransactions (users, objects, transactions, numberOfTransactions) {
-  yield* applyTransactions(1, numberOfTransactions, objects, users, transactions, true)
-  yield Y.utils.globalRoom.flushAll()
-  yield Promise.all(objects.map(fixAwaitingInType))
-})
-
-g.applyRandomTransactionsAllRejoinNoGC = async(function * applyRandomTransactions (users, objects, transactions, numberOfTransactions) {
-  yield* applyTransactions(1, numberOfTransactions, objects, users, transactions)
-  yield Promise.all(objects.map(fixAwaitingInType))
-  yield Y.utils.globalRoom.flushAll()
-  yield Promise.all(objects.map(fixAwaitingInType))
-  for (var u in users) {
-    yield Promise.all(objects.map(fixAwaitingInType))
-    yield users[u].reconnect()
-    yield Promise.all(objects.map(fixAwaitingInType))
-  }
-  yield Promise.all(objects.map(fixAwaitingInType))
-  yield Y.utils.globalRoom.flushAll()
-  yield Promise.all(objects.map(fixAwaitingInType))
-  yield g.garbageCollectAllUsers(users)
-})
-
-g.applyRandomTransactionsWithGC = async(function * applyRandomTransactions (users, objects, transactions, numberOfTransactions) {
-  yield* applyTransactions(1, numberOfTransactions, objects, users.slice(1), transactions)
-  yield Y.utils.globalRoom.flushAll()
-  yield Promise.all(objects.map(fixAwaitingInType))
-  for (var u in users) {
-    // TODO: here, we enforce that two users never sync at the same time with u[0]
-    //       enforce that in the connector itself!
-    yield users[u].reconnect()
-  }
-  yield Y.utils.globalRoom.flushAll()
-  yield Promise.all(objects.map(fixAwaitingInType))
-  yield g.garbageCollectAllUsers(users)
-})
-
-g.garbageCollectAllUsers = async(function * garbageCollectAllUsers (users) {
-  yield Y.utils.globalRoom.flushAll()
-  for (var i in users) {
-    yield users[i].db.emptyGarbageCollector()
-  }
-})
-
-g.compareAllUsers = async(function * compareAllUsers (users) {
-  var s1, s2 // state sets
-  var ds1, ds2 // delete sets
-  var allDels1, allDels2 // all deletions
-  var db1 = [] // operation store of user1
-
-  yield Y.utils.globalRoom.flushAll()
-  yield g.garbageCollectAllUsers(users)
-  yield Y.utils.globalRoom.flushAll()
-
-  // disconnect, then reconnect all users
-  // We do this to make sure that the gc is updated by everyone
-  for (var i = 0; i < users.length; i++) {
-    yield users[i].disconnect()
-    yield wait()
-    yield users[i].reconnect()
-  }
-  yield wait()
-  yield Y.utils.globalRoom.flushAll()
-
-  // t1 and t2 basically do the same. They define t[1,2], ds[1,2], and allDels[1,2]
-  function * t1 () {
-    s1 = yield* this.getStateSet()
-    ds1 = yield* this.getDeleteSet()
-    allDels1 = []
-    yield* this.ds.iterate(this, null, null, function * (d) {
-      allDels1.push(d)
-    })
-  }
-  function * t2 () {
-    s2 = yield* this.getStateSet()
-    ds2 = yield* this.getDeleteSet()
-    allDels2 = []
-    yield* this.ds.iterate(this, null, null, function * (d) {
-      allDels2.push(d)
-    })
-  }
-
-  var buffer = Y.utils.globalRoom.buffers
-  for (var name in buffer) {
-    if (buffer[name].length > 0) {
-      // not all ops were transmitted..
-      debugger // eslint-disable-line
-    }
-  }
-
-  for (var uid = 0; uid < users.length; uid++) {
-    var u = users[uid]
-    u.db.requestTransaction(function * () {
-      var sv = yield* this.getStateVector()
-      for (var s of sv) {
-        yield* this.updateState(s.user)
-      }
-      // compare deleted ops against deleteStore
-      yield* this.os.iterate(this, null, null, function * (o) {
-        if (o.deleted === true) {
-          expect(yield* this.isDeleted(o.id)).toBeTruthy()
-        }
-      })
-      // compare deleteStore against deleted ops
-      var ds = []
-      yield* this.ds.iterate(this, null, null, function * (d) {
-        ds.push(d)
-      })
-      for (var j in ds) {
-        var d = ds[j]
-        for (var i = 0; i < d.len; i++) {
-          var o = yield* this.getInsertion([d.id[0], d.id[1] + i])
-          // gc'd or deleted
-          if (d.gc) {
-            expect(o).toBeFalsy()
-          } else {
-            expect(o.deleted).toBeTruthy()
-          }
-        }
-      }
-    })
-    // compare allDels tree
-    if (s1 == null) {
-      u.db.requestTransaction(function * () {
-        yield* t1.call(this)
-        yield* this.os.iterate(this, null, null, function * (o) {
-          o = Y.utils.copyObject(o)
-          delete o.origin
-          delete o.originOf
-          db1.push(o)
-        })
-      })
-    } else {
-      u.db.requestTransaction(function * () {
-        yield* t2.call(this)
-        var db2 = []
-        yield* this.os.iterate(this, null, null, function * (o) {
-          o = Y.utils.copyObject(o)
-          delete o.origin
-          delete o.originOf
-          db2.push(o)
-        })
-        expect(s1).toEqual(s2)
-        expect(allDels1).toEqual(allDels2) // inner structure
-        expect(ds1).toEqual(ds2) // exported structure
-        db2.forEach((o, i) => {
-          expect(db1[i]).toEqual(o)
-        })
-      })
-    }
-    yield u.db.whenTransactionsFinished()
-  }
-})
-
-g.createUsers = async(function * createUsers (self, numberOfUsers, database, initType) {
-  if (Y.utils.globalRoom.users[0] != null) {
-    yield Y.utils.globalRoom.flushAll()
-  }
-  // destroy old users
-  for (var u in Y.utils.globalRoom.users) {
-    Y.utils.globalRoom.users[u].y.destroy()
-  }
-  self.users = null
-
-  var promises = []
-  for (var i = 0; i < numberOfUsers; i++) {
-    promises.push(Y({
-      db: {
-        name: database,
-        namespace: 'User ' + i,
-        cleanStart: true,
-        gcTimeout: -1,
-        gc: true,
-        repairCheckInterval: -1
-      },
-      connector: {
-        name: 'Test',
-        debug: false
-      },
-      share: {
-        root: initType || 'Map'
-      }
-    }))
-  }
-  self.users = yield Promise.all(promises)
-  self.types = self.users.map(function (u) { return u.share.root })
-  return self.users
-})
-
-/*
-  Until async/await arrives in js, we use this function to wait for promises
-  by yielding them.
-*/
-function async (makeGenerator) {
-  return function (arg) {
-    var generator = makeGenerator.apply(this, arguments)
-
-    function handle (result) {
-      if (result.done) return Promise.resolve(result.value)
-
-      return Promise.resolve(result.value).then(function (res) {
-        return handle(generator.next(res))
-      }, function (err) {
-        return handle(generator.throw(err))
-      })
-    }
-    try {
-      return handle(generator.next())
-    } catch (ex) {
-      generator.throw(ex)
-      // return Promise.reject(ex)
-    }
-  }
-}
-g.async = async
-
-function logUsers (self) {
-  if (self.constructor === Array) {
-    self = {users: self}
-  }
-  self.users[0].db.logTable()
-  self.users[1].db.logTable()
-  self.users[2].db.logTable()
-}
-
-g.logUsers = logUsers

src/Struct.js

@@ -1,414 +0,0 @@
-/* @flow */
-'use strict'
-
-/*
- An operation also defines the structure of a type. This is why operation and
- structure are used interchangeably here.
-
- It must be of the type Object. I hope to achieve some performance
- improvements when working on databases that support the json format.
-
- An operation must have the following properties:
-
- * encode
-     - Encode the structure in a readable format (preferably string- todo)
- * decode (todo)
-     - decode structure to json
- * execute
-     - Execute the semantics of an operation.
- * requiredOps
-     - Operations that are required to execute this operation.
-*/
-module.exports = function (Y/* :any */) {
-  var Struct = {
-    /* This is the only operation that is actually not a structure, because
-    it is not stored in the OS. This is why it _does not_ have an id
-
-    op = {
-      target: Id
-    }
-    */
-    Delete: {
-      encode: function (op) {
-        return {
-          target: op.target,
-          length: op.length || 0,
-          struct: 'Delete'
-        }
-      },
-      requiredOps: function (op) {
-        return [] // [op.target]
-      },
-      execute: function * (op) {
-        return yield* this.deleteOperation(op.target, op.length || 1)
-      }
-    },
-    Insert: {
-      /* {
-          content: [any],
-          opContent: Id,
-          id: Id,
-          left: Id,
-          origin: Id,
-          right: Id,
-          parent: Id,
-          parentSub: string (optional), // child of Map type
-        }
-      */
-      encode: function (op/* :Insertion */) /* :Insertion */ {
-        // TODO: you could not send the "left" property, then you also have to
-        // "op.left = null" in $execute or $decode
-        var e/* :any */ = {
-          id: op.id,
-          left: op.left,
-          right: op.right,
-          origin: op.origin,
-          parent: op.parent,
-          struct: op.struct
-        }
-        if (op.parentSub != null) {
-          e.parentSub = op.parentSub
-        }
-        if (op.hasOwnProperty('opContent')) {
-          e.opContent = op.opContent
-        } else {
-          e.content = op.content.slice()
-        }
-
-        return e
-      },
-      requiredOps: function (op) {
-        var ids = []
-        if (op.left != null) {
-          ids.push(op.left)
-        }
-        if (op.right != null) {
-          ids.push(op.right)
-        }
-        if (op.origin != null && !Y.utils.compareIds(op.left, op.origin)) {
-          ids.push(op.origin)
-        }
-        // if (op.right == null && op.left == null) {
-        ids.push(op.parent)
-
-        if (op.opContent != null) {
-          ids.push(op.opContent)
-        }
-        return ids
-      },
-      getDistanceToOrigin: function * (op) {
-        if (op.left == null) {
-          return 0
-        } else {
-          var d = 0
-          var o = yield* this.getInsertion(op.left)
-          while (!Y.utils.matchesId(o, op.origin)) {
-            d++
-            if (o.left == null) {
-              break
-            } else {
-              o = yield* this.getInsertion(o.left)
-            }
-          }
-          return d
-        }
-      },
-      /*
-      # $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!)
-      */
-      execute: function * (op) {
-        var i // loop counter
-
-        // during this function some ops may get split into two pieces (e.g. with getInsertionCleanEnd)
-        // We try to merge them later, if possible
-        var tryToRemergeLater = []
-
-        if (op.origin != null) { // TODO: !== instead of !=
-          // we save in origin that op originates in it
-          // we need that later when we eventually garbage collect origin (see transaction)
-          var origin = yield* this.getInsertionCleanEnd(op.origin)
-          if (origin.originOf == null) {
-            origin.originOf = []
-          }
-          origin.originOf.push(op.id)
-          yield* this.setOperation(origin)
-          if (origin.right != null) {
-            tryToRemergeLater.push(origin.right)
-          }
-        }
-        var distanceToOrigin = i = yield* Struct.Insert.getDistanceToOrigin.call(this, op) // most cases: 0 (starts from 0)
-
-        // now we begin to insert op in the list of insertions..
-        var o
-        var parent
-        var start
-
-        // find o. o is the first conflicting operation
-        if (op.left != null) {
-          o = yield* this.getInsertionCleanEnd(op.left)
-          if (!Y.utils.compareIds(op.left, op.origin) && o.right != null) {
-            // only if not added previously
-            tryToRemergeLater.push(o.right)
-          }
-          o = (o.right == null) ? null : yield* this.getOperation(o.right)
-        } else { // left == null
-          parent = yield* this.getOperation(op.parent)
-          let startId = op.parentSub ? parent.map[op.parentSub] : parent.start
-          start = startId == null ? null : yield* this.getOperation(startId)
-          o = start
-        }
-
-        // make sure to split op.right if necessary (also add to tryCombineWithLeft)
-        if (op.right != null) {
-          tryToRemergeLater.push(op.right)
-          yield* this.getInsertionCleanStart(op.right)
-        }
-
-        // handle conflicts
-        while (true) {
-          if (o != null && !Y.utils.compareIds(o.id, op.right)) {
-            var oOriginDistance = yield* Struct.Insert.getDistanceToOrigin.call(this, o)
-            if (oOriginDistance === i) {
-              // case 1
-              if (o.id[0] < op.id[0]) {
-                op.left = Y.utils.getLastId(o)
-                distanceToOrigin = i + 1 // just ignore o.content.length, doesn't make a difference
-              }
-            } else if (oOriginDistance < i) {
-              // case 2
-              if (i - distanceToOrigin <= oOriginDistance) {
-                op.left = Y.utils.getLastId(o)
-                distanceToOrigin = i + 1 // just ignore o.content.length, doesn't make a difference
-              }
-            } else {
-              break
-            }
-            i++
-            if (o.right != null) {
-              o = yield* this.getInsertion(o.right)
-            } else {
-              o = null
-            }
-          } else {
-            break
-          }
-        }
-
-        // reconnect..
-        var left = null
-        var right = null
-        if (parent == null) {
-          parent = yield* this.getOperation(op.parent)
-        }
-
-        // reconnect left and set right of op
-        if (op.left != null) {
-          left = yield* this.getInsertion(op.left)
-          // link left
-          op.right = left.right
-          left.right = op.id
-
-          yield* this.setOperation(left)
-        } else {
-          // set op.right from parent, if necessary
-          op.right = op.parentSub ? parent.map[op.parentSub] || null : parent.start
-        }
-        // reconnect right
-        if (op.right != null) {
-          // TODO: wanna connect right too?
-          right = yield* this.getOperation(op.right)
-          right.left = Y.utils.getLastId(op)
-
-          // if right exists, and it is supposed to be gc'd. Remove it from the gc
-          if (right.gc != null) {
-            if (right.content != null && right.content.length > 1) {
-              right = yield* this.getInsertionCleanEnd(right.id)
-            }
-            this.store.removeFromGarbageCollector(right)
-          }
-          yield* this.setOperation(right)
-        }
-
-        // update parents .map/start/end properties
-        if (op.parentSub != null) {
-          if (left == null) {
-            parent.map[op.parentSub] = op.id
-            yield* this.setOperation(parent)
-          }
-          // is a child of a map struct.
-          // Then also make sure that only the most left element is not deleted
-          // We do not call the type in this case (this is what the third parameter is for)
-          if (op.right != null) {
-            yield* this.deleteOperation(op.right, 1, true)
-          }
-          if (op.left != null) {
-            yield* this.deleteOperation(op.id, 1, true)
-          }
-        } else {
-          if (right == null || left == null) {
-            if (right == null) {
-              parent.end = Y.utils.getLastId(op)
-            }
-            if (left == null) {
-              parent.start = op.id
-            }
-            yield* this.setOperation(parent)
-          }
-        }
-
-        // try to merge original op.left and op.origin
-        for (i = 0; i < tryToRemergeLater.length; i++) {
-          var m = yield* this.getOperation(tryToRemergeLater[i])
-          yield* this.tryCombineWithLeft(m)
-        }
-      }
-    },
-    List: {
-      /*
-      {
-        start: null,
-        end: null,
-        struct: "List",
-        type: "",
-        id: this.os.getNextOpId(1)
-      }
-      */
-      create: function (id) {
-        return {
-          start: null,
-          end: null,
-          struct: 'List',
-          id: id
-        }
-      },
-      encode: function (op) {
-        var e = {
-          struct: 'List',
-          id: op.id,
-          type: op.type
-        }
-        if (op.requires != null) {
-          e.requires = op.requires
-        }
-        if (op.info != null) {
-          e.info = op.info
-        }
-        return e
-      },
-      requiredOps: function () {
-        /*
-        var ids = []
-        if (op.start != null) {
-          ids.push(op.start)
-        }
-        if (op.end != null){
-          ids.push(op.end)
-        }
-        return ids
-        */
-        return []
-      },
-      execute: function * (op) {
-        op.start = null
-        op.end = null
-      },
-      ref: function * (op, pos) {
-        if (op.start == null) {
-          return null
-        }
-        var res = null
-        var o = yield* this.getOperation(op.start)
-
-        while (true) {
-          if (!o.deleted) {
-            res = o
-            pos--
-          }
-          if (pos >= 0 && o.right != null) {
-            o = yield* this.getOperation(o.right)
-          } else {
-            break
-          }
-        }
-        return res
-      },
-      map: function * (o, f) {
-        o = o.start
-        var res = []
-        while (o != null) { // TODO: change to != (at least some convention)
-          var operation = yield* this.getOperation(o)
-          if (!operation.deleted) {
-            res.push(f(operation))
-          }
-          o = operation.right
-        }
-        return res
-      }
-    },
-    Map: {
-      /*
-        {
-          map: {},
-          struct: "Map",
-          type: "",
-          id: this.os.getNextOpId(1)
-        }
-      */
-      create: function (id) {
-        return {
-          id: id,
-          map: {},
-          struct: 'Map'
-        }
-      },
-      encode: function (op) {
-        var e = {
-          struct: 'Map',
-          type: op.type,
-          id: op.id,
-          map: {} // overwrite map!!
-        }
-        if (op.requires != null) {
-          e.requires = op.requires
-        }
-        if (op.info != null) {
-          e.info = op.info
-        }
-        return e
-      },
-      requiredOps: function () {
-        return []
-      },
-      execute: function * () {},
-      /*
-        Get a property by name
-      */
-      get: function * (op, name) {
-        var oid = op.map[name]
-        if (oid != null) {
-          var res = yield* this.getOperation(oid)
-          if (res == null || res.deleted) {
-            return void 0
-          } else if (res.opContent == null) {
-            return res.content[0]
-          } else {
-            return yield* this.getType(res.opContent)
-          }
-        }
-      }
-    }
-  }
-  Y.Struct = Struct
-}

src/Utils.js

@@ -1,795 +0,0 @@
-/* @flow */
-'use strict'
-
-/*
-  EventHandler is an helper class for constructing custom types.
-
-  Why: When constructing custom types, you sometimes want your types to work
-  synchronous: E.g.
-  ``` Synchronous
-    mytype.setSomething("yay")
-    mytype.getSomething() === "yay"
-  ```
-  versus
-  ``` Asynchronous
-    mytype.setSomething("yay")
-    mytype.getSomething() === undefined
-    mytype.waitForSomething().then(function(){
-      mytype.getSomething() === "yay"
-    })
-  ```
-
-  The structures usually work asynchronously (you have to wait for the
-  database request to finish). EventHandler helps you to make your type
-  synchronous.
-*/
-module.exports = function (Y /* : any*/) {
-  Y.utils = {}
-
-  Y.utils.bubbleEvent = function (type, event) {
-    type.eventHandler.callEventListeners(event)
-    event.path = []
-    while (type != null && type._deepEventHandler != null) {
-      type._deepEventHandler.callEventListeners(event)
-      var parent = null
-      if (type._parent != null) {
-        parent = type.os.getType(type._parent)
-      }
-      if (parent != null && parent._getPathToChild != null) {
-        event.path = [parent._getPathToChild(type._model)].concat(event.path)
-        type = parent
-      } else {
-        type = null
-      }
-    }
-  }
-
-  class EventListenerHandler {
-    constructor () {
-      this.eventListeners = []
-    }
-    destroy () {
-      this.eventListeners = null
-    }
-     /*
-      Basic event listener boilerplate...
-    */
-    addEventListener (f) {
-      this.eventListeners.push(f)
-    }
-    removeEventListener (f) {
-      this.eventListeners = this.eventListeners.filter(function (g) {
-        return f !== g
-      })
-    }
-    removeAllEventListeners () {
-      this.eventListeners = []
-    }
-    callEventListeners (event) {
-      for (var i = 0; i < this.eventListeners.length; i++) {
-        try {
-          var _event = {}
-          for (var name in event) {
-            _event[name] = event[name]
-          }
-          this.eventListeners[i](_event)
-        } catch (e) {
-          console.error('Your observer threw an error. This error was caught so that Yjs still can ensure data consistency! In order to debug this error you have to check "Pause On Caught Exceptions"', e)
-        }
-      }
-    }
-  }
-  Y.utils.EventListenerHandler = EventListenerHandler
-
-  class EventHandler extends EventListenerHandler {
-    /* ::
-    waiting: Array<Insertion | Deletion>;
-    awaiting: number;
-    onevent: Function;
-    eventListeners: Array<Function>;
-    */
-    /*
-      onevent: is called when the structure changes.
-
-      Note: "awaiting opertations" is used to denote operations that were
-      prematurely called. Events for received operations can not be executed until
-      all prematurely called operations were executed ("waiting operations")
-    */
-    constructor (onevent /* : Function */) {
-      super()
-      this.waiting = []
-      this.awaiting = 0
-      this.onevent = onevent
-    }
-    destroy () {
-      super.destroy()
-      this.waiting = null
-      this.onevent = null
-    }
-    /*
-      Call this when a new operation arrives. It will be executed right away if
-      there are no waiting operations, that you prematurely executed
-    */
-    receivedOp (op) {
-      if (this.awaiting <= 0) {
-        this.onevent(op)
-      } else if (op.struct === 'Delete') {
-        var self = this
-        var checkDelete = function checkDelete (d) {
-          if (d.length == null) {
-            throw new Error('This shouldn\'t happen! d.length must be defined!')
-          }
-          // we check if o deletes something in self.waiting
-          // if so, we remove the deleted operation
-          for (var w = 0; w < self.waiting.length; w++) {
-            var i = self.waiting[w]
-            if (i.struct === 'Insert' && i.id[0] === d.target[0]) {
-              var iLength = i.hasOwnProperty('content') ? i.content.length : 1
-              var dStart = d.target[1]
-              var dEnd = d.target[1] + (d.length || 1)
-              var iStart = i.id[1]
-              var iEnd = i.id[1] + iLength
-              // Check if they don't overlap
-              if (iEnd <= dStart || dEnd <= iStart) {
-                // no overlapping
-                continue
-              }
-              // we check all overlapping cases. All cases:
-              /*
-                1)  iiiii
-                      ddddd
-                    --> modify i and d
-                2)  iiiiiii
-                      ddddd
-                    --> modify i, remove d
-                3)  iiiiiii
-                      ddd
-                    --> remove d, modify i, and create another i (for the right hand side)
-                4)  iiiii
-                    ddddddd
-                    --> remove i, modify d
-                5)  iiiiiii
-                    ddddddd
-                    --> remove both i and d (**)
-                6)  iiiiiii
-                    ddddd
-                    --> modify i, remove d
-                7)    iii
-                    ddddddd
-                    --> remove i, create and apply two d with checkDelete(d) (**)
-                8)    iiiii
-                    ddddddd
-                    --> remove i, modify d (**)
-                9)    iiiii
-                    ddddd
-                    --> modify i and d
-                (**) (also check if i contains content or type)
-              */
-              // TODO: I left some debugger statements, because I want to debug all cases once in production. REMEMBER END TODO
-              if (iStart < dStart) {
-                if (dStart < iEnd) {
-                  if (iEnd < dEnd) {
-                    // Case 1
-                    // remove the right part of i's content
-                    i.content.splice(dStart - iStart)
-                    // remove the start of d's deletion
-                    d.length = dEnd - iEnd
-                    d.target = [d.target[0], iEnd]
-                    continue
-                  } else if (iEnd === dEnd) {
-                    // Case 2
-                    i.content.splice(dStart - iStart)
-                    // remove d, we do that by simply ending this function
-                    return
-                  } else { // (dEnd < iEnd)
-                    // Case 3
-                    var newI = {
-                      id: [i.id[0], dEnd],
-                      content: i.content.slice(dEnd - iStart),
-                      struct: 'Insert'
-                    }
-                    self.waiting.push(newI)
-                    i.content.splice(dStart - iStart)
-                    return
-                  }
-                }
-              } else if (dStart === iStart) {
-                if (iEnd < dEnd) {
-                  // Case 4
-                  d.length = dEnd - iEnd
-                  d.target = [d.target[0], iEnd]
-                  i.content = []
-                  continue
-                } else if (iEnd === dEnd) {
-                  // Case 5
-                  self.waiting.splice(w, 1)
-                  return
-                } else { // (dEnd < iEnd)
-                  // Case 6
-                  i.content = i.content.slice(dEnd - iStart)
-                  i.id = [i.id[0], dEnd]
-                  return
-                }
-              } else { // (dStart < iStart)
-                if (iStart < dEnd) {
-                  // they overlap
-                  /*
-                  7)    iii
-                      ddddddd
-                      --> remove i, create and apply two d with checkDelete(d) (**)
-                  8)    iiiii
-                      ddddddd
-                      --> remove i, modify d (**)
-                  9)    iiiii
-                      ddddd
-                      --> modify i and d
-                  */
-                  if (iEnd < dEnd) {
-                    // Case 7
-                    // debugger // TODO: You did not test this case yet!!!! (add the debugger here)
-                    self.waiting.splice(w, 1)
-                    checkDelete({
-                      target: [d.target[0], dStart],
-                      length: iStart - dStart,
-                      struct: 'Delete'
-                    })
-                    checkDelete({
-                      target: [d.target[0], iEnd],
-                      length: iEnd - dEnd,
-                      struct: 'Delete'
-                    })
-                    return
-                  } else if (iEnd === dEnd) {
-                    // Case 8
-                    self.waiting.splice(w, 1)
-                    w--
-                    d.length -= iLength
-                    continue
-                  } else { // dEnd < iEnd
-                    // Case 9
-                    d.length = iStart - dStart
-                    i.content.splice(0, dEnd - iStart)
-                    i.id = [i.id[0], dEnd]
-                    continue
-                  }
-                }
-              }
-            }
-          }
-          // finished with remaining operations
-          self.waiting.push(d)
-        }
-        if (op.key == null) {
-          // deletes in list
-          checkDelete(op)
-        } else {
-          // deletes in map
-          this.waiting.push(op)
-        }
-      } else {
-        this.waiting.push(op)
-      }
-    }
-    /*
-      You created some operations, and you want the `onevent` function to be
-      called right away. Received operations will not be executed untill all
-      prematurely called operations are executed
-    */
-    awaitAndPrematurelyCall (ops) {
-      this.awaiting++
-      ops.map(Y.utils.copyOperation).forEach(this.onevent)
-    }
-    * awaitOps (transaction, f, args) {
-      function notSoSmartSort (array) {
-        // this function sorts insertions in a executable order
-        var result = []
-        while (array.length > 0) {
-          for (var i = 0; i < array.length; i++) {
-            var independent = true
-            for (var j = 0; j < array.length; j++) {
-              if (Y.utils.matchesId(array[j], array[i].left)) {
-                // array[i] depends on array[j]
-                independent = false
-                break
-              }
-            }
-            if (independent) {
-              result.push(array.splice(i, 1)[0])
-              i--
-            }
-          }
-        }
-        return result
-      }
-      var before = this.waiting.length
-      // somehow create new operations
-      yield* f.apply(transaction, args)
-      // remove all appended ops / awaited ops
-      this.waiting.splice(before)
-      if (this.awaiting > 0) this.awaiting--
-      // if there are no awaited ops anymore, we can update all waiting ops, and send execute them (if there are still no awaited ops)
-      if (this.awaiting === 0 && this.waiting.length > 0) {
-        // update all waiting ops
-        for (let i = 0; i < this.waiting.length; i++) {
-          var o = this.waiting[i]
-          if (o.struct === 'Insert') {
-            var _o = yield* transaction.getInsertion(o.id)
-            if (_o.parentSub != null && _o.left != null) {
-              // if o is an insertion of a map struc (parentSub is defined), then it shouldn't be necessary to compute left
-              this.waiting.splice(i, 1)
-              i-- // update index
-            } else if (!Y.utils.compareIds(_o.id, o.id)) {
-              // o got extended
-              o.left = [o.id[0], o.id[1] - 1]
-            } else if (_o.left == null) {
-              o.left = null
-            } else {
-              // find next undeleted op
-              var left = yield* transaction.getInsertion(_o.left)
-              while (left.deleted != null) {
-                if (left.left != null) {
-                  left = yield* transaction.getInsertion(left.left)
-                } else {
-                  left = null
-                  break
-                }
-              }
-              o.left = left != null ? Y.utils.getLastId(left) : null
-            }
-          }
-        }
-        // the previous stuff was async, so we have to check again!
-        // We also pull changes from the bindings, if there exists such a method, this could increase awaiting too
-        if (this._pullChanges != null) {
-          this._pullChanges()
-        }
-        if (this.awaiting === 0) {
-          // sort by type, execute inserts first
-          var ins = []
-          var dels = []
-          this.waiting.forEach(function (o) {
-            if (o.struct === 'Delete') {
-              dels.push(o)
-            } else {
-              ins.push(o)
-            }
-          })
-          this.waiting = []
-          // put in executable order
-          ins = notSoSmartSort(ins)
-          // this.onevent can trigger the creation of another operation
-          // -> check if this.awaiting increased & stop computation if it does
-          for (var i = 0; i < ins.length; i++) {
-            if (this.awaiting === 0) {
-              this.onevent(ins[i])
-            } else {
-              this.waiting = this.waiting.concat(ins.slice(i))
-              break
-            }
-          }
-          for (i = 0; i < dels.length; i++) {
-            if (this.awaiting === 0) {
-              this.onevent(dels[i])
-            } else {
-              this.waiting = this.waiting.concat(dels.slice(i))
-              break
-            }
-          }
-        }
-      }
-    }
-    // TODO: Remove awaitedInserts and awaitedDeletes in favor of awaitedOps, as they are deprecated and do not always work
-    // Do this in one of the coming releases that are breaking anyway
-    /*
-      Call this when you successfully awaited the execution of n Insert operations
-    */
-    awaitedInserts (n) {
-      var ops = this.waiting.splice(this.waiting.length - n)
-      for (var oid = 0; oid < ops.length; oid++) {
-        var op = ops[oid]
-        if (op.struct === 'Insert') {
-          for (var i = this.waiting.length - 1; i >= 0; i--) {
-            let w = this.waiting[i]
-            // TODO: do I handle split operations correctly here? Super unlikely, but yeah..
-            // Also: can this case happen? Can op be inserted in the middle of a larger op that is in $waiting?
-            if (w.struct === 'Insert') {
-              if (Y.utils.matchesId(w, op.left)) {
-                // include the effect of op in w
-                w.right = op.id
-                // exclude the effect of w in op
-                op.left = w.left
-              } else if (Y.utils.compareIds(w.id, op.right)) {
-                // similar..
-                w.left = Y.utils.getLastId(op)
-                op.right = w.right
-              }
-            }
-          }
-        } else {
-          throw new Error('Expected Insert Operation!')
-        }
-      }
-      this._tryCallEvents(n)
-    }
-    /*
-      Call this when you successfully awaited the execution of n Delete operations
-    */
-    awaitedDeletes (n, newLeft) {
-      var ops = this.waiting.splice(this.waiting.length - n)
-      for (var j = 0; j < ops.length; j++) {
-        var del = ops[j]
-        if (del.struct === 'Delete') {
-          if (newLeft != null) {
-            for (var i = 0; i < this.waiting.length; i++) {
-              let w = this.waiting[i]
-              // We will just care about w.left
-              if (w.struct === 'Insert' && Y.utils.compareIds(del.target, w.left)) {
-                w.left = newLeft
-              }
-            }
-          }
-        } else {
-          throw new Error('Expected Delete Operation!')
-        }
-      }
-      this._tryCallEvents(n)
-    }
-    /* (private)
-      Try to execute the events for the waiting operations
-    */
-    _tryCallEvents () {
-      function notSoSmartSort (array) {
-        var result = []
-        while (array.length > 0) {
-          for (var i = 0; i < array.length; i++) {
-            var independent = true
-            for (var j = 0; j < array.length; j++) {
-              if (Y.utils.matchesId(array[j], array[i].left)) {
-                // array[i] depends on array[j]
-                independent = false
-                break
-              }
-            }
-            if (independent) {
-              result.push(array.splice(i, 1)[0])
-              i--
-            }
-          }
-        }
-        return result
-      }
-      if (this.awaiting > 0) this.awaiting--
-      if (this.awaiting === 0 && this.waiting.length > 0) {
-        var ins = []
-        var dels = []
-        this.waiting.forEach(function (o) {
-          if (o.struct === 'Delete') {
-            dels.push(o)
-          } else {
-            ins.push(o)
-          }
-        })
-        ins = notSoSmartSort(ins)
-        ins.forEach(this.onevent)
-        dels.forEach(this.onevent)
-        this.waiting = []
-      }
-    }
-  }
-  Y.utils.EventHandler = EventHandler
-
-  /*
-    Default class of custom types!
-  */
-  class CustomType {
-    getPath () {
-      var parent = null
-      if (this._parent != null) {
-        parent = this.os.getType(this._parent)
-      }
-      if (parent != null && parent._getPathToChild != null) {
-        var firstKey = parent._getPathToChild(this._model)
-        var parentKeys = parent.getPath()
-        parentKeys.push(firstKey)
-        return parentKeys
-      } else {
-        return []
-      }
-    }
-  }
-  Y.utils.CustomType = CustomType
-
-  /*
-    A wrapper for the definition of a custom type.
-    Every custom type must have three properties:
-
-    * struct
-      - Structname of this type
-    * initType
-      - Given a model, creates a custom type
-    * class
-      - the constructor of the custom type (e.g. in order to inherit from a type)
-  */
-  class CustomTypeDefinition { // eslint-disable-line
-    /* ::
-    struct: any;
-    initType: any;
-    class: Function;
-    name: String;
-    */
-    constructor (def) {
-      if (def.struct == null ||
-        def.initType == null ||
-        def.class == null ||
-        def.name == null ||
-        def.createType == null
-      ) {
-        throw new Error('Custom type was not initialized correctly!')
-      }
-      this.struct = def.struct
-      this.initType = def.initType
-      this.createType = def.createType
-      this.class = def.class
-      this.name = def.name
-      if (def.appendAdditionalInfo != null) {
-        this.appendAdditionalInfo = def.appendAdditionalInfo
-      }
-      this.parseArguments = (def.parseArguments || function () {
-        return [this]
-      }).bind(this)
-      this.parseArguments.typeDefinition = this
-    }
-  }
-  Y.utils.CustomTypeDefinition = CustomTypeDefinition
-
-  Y.utils.isTypeDefinition = function isTypeDefinition (v) {
-    if (v != null) {
-      if (v instanceof Y.utils.CustomTypeDefinition) return [v]
-      else if (v.constructor === Array && v[0] instanceof Y.utils.CustomTypeDefinition) return v
-      else if (v instanceof Function && v.typeDefinition instanceof Y.utils.CustomTypeDefinition) return [v.typeDefinition]
-    }
-    return false
-  }
-
-  /*
-    Make a flat copy of an object
-    (just copy properties)
-  */
-  function copyObject (o) {
-    var c = {}
-    for (var key in o) {
-      c[key] = o[key]
-    }
-    return c
-  }
-  Y.utils.copyObject = copyObject
-
-  /*
-    Copy an operation, so that it can be manipulated.
-    Note: You must not change subproperties (except o.content)!
-  */
-  function copyOperation (o) {
-    o = copyObject(o)
-    if (o.content != null) {
-      o.content = o.content.map(function (c) { return c })
-    }
-    return o
-  }
-
-  Y.utils.copyOperation = copyOperation
-
-  /*
-    Defines a smaller relation on Id's
-  */
-  function smaller (a, b) {
-    return a[0] < b[0] || (a[0] === b[0] && (a[1] < b[1] || typeof a[1] < typeof b[1]))
-  }
-  Y.utils.smaller = smaller
-
-  function inDeletionRange (del, ins) {
-    return del.target[0] === ins[0] && del.target[1] <= ins[1] && ins[1] < del.target[1] + (del.length || 1)
-  }
-  Y.utils.inDeletionRange = inDeletionRange
-
-  function compareIds (id1, id2) {
-    if (id1 == null || id2 == null) {
-      return id1 === id2
-    } else {
-      return id1[0] === id2[0] && id1[1] === id2[1]
-    }
-  }
-  Y.utils.compareIds = compareIds
-
-  function matchesId (op, id) {
-    if (id == null || op == null) {
-      return id === op
-    } else {
-      if (id[0] === op.id[0]) {
-        if (op.content == null) {
-          return id[1] === op.id[1]
-        } else {
-          return id[1] >= op.id[1] && id[1] < op.id[1] + op.content.length
-        }
-      }
-    }
-  }
-  Y.utils.matchesId = matchesId
-
-  function getLastId (op) {
-    if (op.content == null || op.content.length === 1) {
-      return op.id
-    } else {
-      return [op.id[0], op.id[1] + op.content.length - 1]
-    }
-  }
-  Y.utils.getLastId = getLastId
-
-  function createEmptyOpsArray (n) {
-    var a = new Array(n)
-    for (var i = 0; i < a.length; i++) {
-      a[i] = {
-        id: [null, null]
-      }
-    }
-    return a
-  }
-
-  function createSmallLookupBuffer (Store) {
-    /*
-      This buffer implements a very small buffer that temporarily stores operations
-      after they are read / before they are written.
-      The buffer basically implements FIFO. Often requested lookups will be re-queued every time they are looked up / written.
-
-      It can speed up lookups on Operation Stores and State Stores. But it does not require notable use of memory or processing power.
-
-      Good for os and ss, bot not for ds (because it often uses methods that require a flush)
-
-      I tried to optimize this for performance, therefore no highlevel operations.
-    */
-    class SmallLookupBuffer extends Store {
-      constructor (arg1, arg2) {
-        // super(...arguments) -- do this when this is supported by stable nodejs
-        super(arg1, arg2)
-        this.writeBuffer = createEmptyOpsArray(5)
-        this.readBuffer = createEmptyOpsArray(10)
-      }
-      * find (id, noSuperCall) {
-        var i, r
-        for (i = this.readBuffer.length - 1; i >= 0; i--) {
-          r = this.readBuffer[i]
-          // we don't have to use compareids, because id is always defined!
-          if (r.id[1] === id[1] && r.id[0] === id[0]) {
-            // found r
-            // move r to the end of readBuffer
-            for (; i < this.readBuffer.length - 1; i++) {
-              this.readBuffer[i] = this.readBuffer[i + 1]
-            }
-            this.readBuffer[this.readBuffer.length - 1] = r
-            return r
-          }
-        }
-        var o
-        for (i = this.writeBuffer.length - 1; i >= 0; i--) {
-          r = this.writeBuffer[i]
-          if (r.id[1] === id[1] && r.id[0] === id[0]) {
-            o = r
-            break
-          }
-        }
-        if (i < 0 && noSuperCall === undefined) {
-          // did not reach break in last loop
-          // read id and put it to the end of readBuffer
-          o = yield* super.find(id)
-        }
-        if (o != null) {
-          for (i = 0; i < this.readBuffer.length - 1; i++) {
-            this.readBuffer[i] = this.readBuffer[i + 1]
-          }
-          this.readBuffer[this.readBuffer.length - 1] = o
-        }
-        return o
-      }
-      * put (o) {
-        var id = o.id
-        var i, r // helper variables
-        for (i = this.writeBuffer.length - 1; i >= 0; i--) {
-          r = this.writeBuffer[i]
-          if (r.id[1] === id[1] && r.id[0] === id[0]) {
-            // is already in buffer
-            // forget r, and move o to the end of writeBuffer
-            for (; i < this.writeBuffer.length - 1; i++) {
-              this.writeBuffer[i] = this.writeBuffer[i + 1]
-            }
-            this.writeBuffer[this.writeBuffer.length - 1] = o
-            break
-          }
-        }
-        if (i < 0) {
-          // did not reach break in last loop
-          // write writeBuffer[0]
-          var write = this.writeBuffer[0]
-          if (write.id[0] !== null) {
-            yield* super.put(write)
-          }
-          // put o to the end of writeBuffer
-          for (i = 0; i < this.writeBuffer.length - 1; i++) {
-            this.writeBuffer[i] = this.writeBuffer[i + 1]
-          }
-          this.writeBuffer[this.writeBuffer.length - 1] = o
-        }
-        // check readBuffer for every occurence of o.id, overwrite if found
-        // whether found or not, we'll append o to the readbuffer
-        for (i = 0; i < this.readBuffer.length - 1; i++) {
-          r = this.readBuffer[i + 1]
-          if (r.id[1] === id[1] && r.id[0] === id[0]) {
-            this.readBuffer[i] = o
-          } else {
-            this.readBuffer[i] = r
-          }
-        }
-        this.readBuffer[this.readBuffer.length - 1] = o
-      }
-      * delete (id) {
-        var i, r
-        for (i = 0; i < this.readBuffer.length; i++) {
-          r = this.readBuffer[i]
-          if (r.id[1] === id[1] && r.id[0] === id[0]) {
-            this.readBuffer[i] = {
-              id: [null, null]
-            }
-          }
-        }
-        yield* this.flush()
-        yield* super.delete(id)
-      }
-      * findWithLowerBound (id) {
-        var o = yield* this.find(id, true)
-        if (o != null) {
-          return o
-        } else {
-          yield* this.flush()
-          return yield* super.findWithLowerBound.apply(this, arguments)
-        }
-      }
-      * findWithUpperBound (id) {
-        var o = yield* this.find(id, true)
-        if (o != null) {
-          return o
-        } else {
-          yield* this.flush()
-          return yield* super.findWithUpperBound.apply(this, arguments)
-        }
-      }
-      * findNext () {
-        yield* this.flush()
-        return yield* super.findNext.apply(this, arguments)
-      }
-      * findPrev () {
-        yield* this.flush()
-        return yield* super.findPrev.apply(this, arguments)
-      }
-      * iterate () {
-        yield* this.flush()
-        yield* super.iterate.apply(this, arguments)
-      }
-      * flush () {
-        for (var i = 0; i < this.writeBuffer.length; i++) {
-          var write = this.writeBuffer[i]
-          if (write.id[0] !== null) {
-            yield* super.put(write)
-            this.writeBuffer[i] = {
-              id: [null, null]
-            }
-          }
-        }
-      }
-    }
-    return SmallLookupBuffer
-  }
-  Y.utils.createSmallLookupBuffer = createSmallLookupBuffer
-
-  // Generates a unique id, for use as a user id.
-  // Thx to @jed for this script https://gist.github.com/jed/982883
-  function generateGuid(a){return a?(a^Math.random()*16>>a/4).toString(16):([1e7]+-1e3+-4e3+-8e3+-1e11).replace(/[018]/g,generateGuid)} // eslint-disable-line
-  Y.utils.generateGuid = generateGuid
-}

src/index.js

@@ -0,0 +1,26 @@
+
+export {
+  Y,
+  Transaction,
+  YArray as Array,
+  YMap as Map,
+  YText as Text,
+  YXmlText as XmlText,
+  YXmlHook as XmlHook,
+  YXmlElement as XmlElement,
+  YXmlFragment as XmlFragment,
+  createCursorFromTypeOffset,
+  createCursorFromJSON,
+  createAbsolutePositionFromCursor,
+  writeCursor,
+  readCursor,
+  ID,
+  createID,
+  compareIDs,
+  getState,
+  getStates,
+  readStatesAsMap,
+  writeStates,
+  writeModel,
+  readModel
+} from './internals.js'

src/internals.js

@@ -0,0 +1,33 @@
+export * from './utils/DeleteSet.js'
+export * from './utils/EventHandler.js'
+export * from './utils/ID.js'
+export * from './utils/isParentOf.js'
+export * from './utils/cursor.js'
+export * from './utils/Snapshot.js'
+export * from './utils/StructStore.js'
+export * from './utils/Transaction.js'
+// export * from './utils/UndoManager.js'
+export * from './utils/Y.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/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/AbstractItem.js'
+export * from './structs/GC.js'
+export * from './structs/ItemBinary.js'
+export * from './structs/ItemDeleted.js'
+export * from './structs/ItemEmbed.js'
+export * from './structs/ItemFormat.js'
+export * from './structs/ItemJSON.js'
+export * from './structs/ItemString.js'
+export * from './structs/ItemType.js'
+
+export * from './utils/encoding.js'

src/structs/AbstractItem.js

@@ -0,0 +1,631 @@
+
+import {
+  readID,
+  createID,
+  writeID,
+  GC,
+  nextID,
+  AbstractStructRef,
+  AbstractStruct,
+  replaceStruct,
+  addStruct,
+  addToDeleteSet,
+  ItemDeleted,
+  findRootTypeKey,
+  compareIDs,
+  getItem,
+  getItemType,
+  getItemCleanEnd,
+  getItemCleanStart,
+  YEvent, StructStore, ID, AbstractType, Y, Transaction // eslint-disable-line
+} from '../internals.js'
+
+import * as error from 'lib0/error.js'
+import * as encoding from 'lib0/encoding.js'
+import * as decoding from 'lib0/decoding.js'
+import * as maplib from 'lib0/map.js'
+import * as set from 'lib0/set.js'
+import * as binary from 'lib0/binary.js'
+
+/**
+ * Split leftItem into two items
+ * @param {Transaction} transaction
+ * @param {AbstractItem} leftItem
+ * @param {number} diff
+ * @return {AbstractItem}
+ *
+ * @function
+ * @private
+ */
+export const splitItem = (transaction, leftItem, diff) => {
+  const id = leftItem.id
+  // create rightItem
+  const rightItem = leftItem.copy(
+    createID(id.client, id.clock + diff),
+    leftItem,
+    createID(id.client, id.clock + diff - 1),
+    leftItem.right,
+    leftItem.rightOrigin,
+    leftItem.parent,
+    leftItem.parentSub
+  )
+  if (leftItem.deleted) {
+    rightItem.deleted = true
+  }
+  // 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.add(rightItem.id)
+  return rightItem
+}
+
+/**
+ * Abstract class that represents any content.
+ */
+export class AbstractItem extends AbstractStruct {
+  /**
+   * @param {ID} id
+   * @param {AbstractItem | null} left
+   * @param {ID | null} origin
+   * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
+   * @param {AbstractType<any>} parent
+   * @param {string | null} parentSub
+   */
+  constructor (id, left, origin, right, rightOrigin, parent, parentSub) {
+    super(id)
+    /**
+     * The item that was originally to the left of this item.
+     * @type {ID | null}
+     * @readonly
+     */
+    this.origin = origin
+    /**
+     * The item that is currently to the left of this item.
+     * @type {AbstractItem | null}
+     */
+    this.left = left
+    /**
+     * The item that is currently to the right of this item.
+     * @type {AbstractItem | null}
+     */
+    this.right = right
+    /**
+     * The item that was originally to the right of this item.
+     * @readonly
+     * @type {ID | null}
+     */
+    this.rightOrigin = rightOrigin
+    /**
+     * The parent type.
+     * @type {AbstractType<any>}
+     * @readonly
+     */
+    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}
+     * @readonly
+     */
+    this.parentSub = parentSub
+    /**
+     * Whether this item was deleted or not.
+     * @type {Boolean}
+     */
+    this.deleted = false
+    /**
+     * If this type's effect is reundone this type refers to the type that undid
+     * this operation.
+     * @type {AbstractItem | null}
+     */
+    this.redone = null
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @private
+   */
+  integrate (transaction) {
+    const store = transaction.y.store
+    const id = this.id
+    const parent = this.parent
+    const parentSub = this.parentSub
+    const length = this.length
+    /**
+     * @type {AbstractItem|null}
+     */
+    let o
+    // set o to the first conflicting item
+    if (this.left !== null) {
+      o = this.left.right
+    } else if (parentSub !== null) {
+      o = parent._map.get(parentSub) || null
+      while (o !== null && o.left !== null) {
+        o = o.left
+      }
+    } else {
+      o = parent._start
+    }
+    // TODO: use something like DeleteSet here (a tree implementation would be best)
+    /**
+     * @type {Set<AbstractItem>}
+     */
+    const conflictingItems = new Set()
+    /**
+     * @type {Set<AbstractItem>}
+     */
+    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 < id.client) {
+          this.left = o
+          conflictingItems.clear()
+        }
+      } else if (o.origin !== null && itemsBeforeOrigin.has(getItem(store, o.origin))) {
+        // case 2
+        if (o.origin === null || !conflictingItems.has(getItem(store, o.origin))) {
+          this.left = o
+          conflictingItems.clear()
+        }
+      } else {
+        break
+      }
+      o = o.right
+    }
+    // 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 (parentSub !== null) {
+        r = parent._map.get(parentSub) || null
+        while (r !== null && r.left !== null) {
+          r = r.left
+        }
+      } else {
+        r = parent._start
+        parent._start = this
+      }
+      this.right = r
+    }
+    if (this.right !== null) {
+      this.right.left = this
+    } else if (parentSub !== null) {
+      // set as current parent value if right === null and this is parentSub
+      parent._map.set(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 (parentSub === null && this.countable && !this.deleted) {
+      parent._length += length
+    }
+    addStruct(store, this)
+    maplib.setIfUndefined(transaction.changed, parent, set.create).add(parentSub)
+    // @ts-ignore
+    if ((parent._item !== null && parent._item.deleted) || (this.right !== null && parentSub !== null)) {
+      // delete if parent is deleted or if this is not the current attribute value of parent
+      this.delete(transaction)
+    }
+  }
+
+  /**
+   * Returns the next non-deleted item
+   * @private
+   */
+  get next () {
+    let n = this.right
+    while (n !== null && n.deleted) {
+      n = n.right
+    }
+    return n
+  }
+
+  /**
+   * Returns the previous non-deleted item
+   * @private
+   */
+  get prev () {
+    let n = this.left
+    while (n !== null && n.deleted) {
+      n = n.left
+    }
+    return n
+  }
+
+  /**
+   * Creates an Item with the same effect as this Item (without position effect)
+   *
+   * @param {ID} id
+   * @param {AbstractItem | null} left
+   * @param {ID | null} origin
+   * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
+   * @param {AbstractType<any>} parent
+   * @param {string | null} parentSub
+   * @return {AbstractItem}
+   *
+   * @private
+   */
+  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
+    throw new Error('unimplemented')
+  }
+
+  /**
+   * Redoes the effect of this operation.
+   *
+   * @param {Transaction} transaction The Yjs instance.
+   * @param {Set<AbstractItem>} redoitems
+   *
+   * @private
+   */
+  redo (transaction, redoitems) {
+    if (this.redone !== null) {
+      return this.redone
+    }
+    /**
+     * @type {any}
+     */
+    let parent = this.parent
+    if (parent === null) {
+      return
+    }
+    let left, right
+    if (this.parentSub === null) {
+      // Is an array item. Insert at the old position
+      left = this.left
+      right = this
+    } else {
+      // Is a map item. Insert as current value
+      left = parent.type._map.get(this.parentSub)
+      right = null
+    }
+    // make sure that parent is redone
+    if (parent._deleted === true && parent.redone === null) {
+      // try to undo parent if it will be undone anyway
+      if (!redoitems.has(parent) || !parent.redo(transaction, redoitems)) {
+        return false
+      }
+    }
+    if (parent.redone !== null) {
+      while (parent.redone !== null) {
+        parent = parent.redone
+      }
+      // find next cloned_redo items
+      while (left !== null) {
+        if (left.redone !== null && left.redone.parent === parent) {
+          left = left.redone
+          break
+        }
+        left = left.left
+      }
+      while (right !== null) {
+        if (right.redone !== null && right.redone.parent === parent) {
+          right = right.redone
+        }
+        right = right.right
+      }
+    }
+    this.redone = this.copy(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, this.parentSub)
+    this.redone.integrate(transaction)
+    return true
+  }
+
+  /**
+   * Computes the last content address of this Item.
+   */
+  get lastId () {
+    return createID(this.id.client, this.id.clock + this.length - 1)
+  }
+
+  /**
+   * Computes the length of this Item.
+   */
+  get length () {
+    return 1
+  }
+
+  /**
+   * 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
+   */
+  get countable () {
+    return true
+  }
+
+  /**
+   * Do not call directly. Always split via StructStore!
+   *
+   * Splits this Item so that another Item can be inserted in-between.
+   * This must be overwritten if _length > 1
+   * Returns right part after split
+   *
+   * (see {@link ItemJSON}/{@link ItemString} for implementation)
+   *
+   * Does not integrate the struct, nor store it in struct store.
+   *
+   * This method should only be cally by StructStore.
+   *
+   * @param {Transaction} transaction
+   * @param {number} diff
+   * @return {AbstractItem}
+   *
+   * @private
+   */
+  splitAt (transaction, diff) {
+    throw new Error('unimplemented')
+  }
+
+  /**
+   * @param {AbstractItem} right
+   * @return {boolean}
+   *
+   * @private
+   */
+  mergeWith (right) {
+    if (compareIDs(right.origin, this.lastId) && this.right === right && compareIDs(this.rightOrigin, right.rightOrigin)) {
+      this.right = right.right
+      if (this.right !== null) {
+        this.right.left = this
+      }
+      return true
+    }
+    return false
+  }
+  /**
+   * Mark this Item as deleted.
+   *
+   * @param {Transaction} transaction
+   */
+  delete (transaction) {
+    if (!this.deleted) {
+      const parent = this.parent
+      // adjust the length of parent
+      if (this.countable && this.parentSub === null) {
+        parent._length -= this.length
+      }
+      this.deleted = true
+      addToDeleteSet(transaction.deleteSet, this.id, this.length)
+      maplib.setIfUndefined(transaction.changed, parent, set.create).add(this.parentSub)
+    }
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {StructStore} store
+   *
+   * @private
+   */
+  gcChildren (transaction, store) { }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {StructStore} store
+   *
+   * @private
+   */
+  gc (transaction, store) {
+    let r
+    if (this.parent._item !== null && this.parent._item.deleted) {
+      r = new GC(this.id, this.length)
+    } else {
+      r = new ItemDeleted(this.id, this.left, this.origin, this.right, this.rightOrigin, this.parent, this.parentSub, this.length)
+      if (r.right !== null) {
+        r.right.left = r
+      } else if (r.parentSub !== null) {
+        r.parent._map.set(r.parentSub, r)
+      }
+      if (r.left !== null) {
+        r.left.right = r
+      } else if (r.parentSub === null) {
+        r.parent._start = r
+      }
+    }
+    replaceStruct(store, this, r)
+    transaction._mergeStructs.add(r.id)
+  }
+
+  /**
+   * @return {Array<any>}
+   */
+  getContent () {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * 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 {encoding.Encoder} encoder The encoder to write data to.
+   * @param {number} offset
+   * @param {number} encodingRef
+   *
+   * @private
+   */
+  write (encoder, offset, encodingRef) {
+    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 = (encodingRef & 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
+    encoding.writeUint8(encoder, info)
+    if (origin !== null) {
+      writeID(encoder, origin)
+    }
+    if (rightOrigin !== null) {
+      writeID(encoder, rightOrigin)
+    }
+    if (origin === null && rightOrigin === null) {
+      const parent = this.parent
+      if (parent._item === null) {
+        // parent type on y._map
+        // find the correct key
+        // @ts-ignore we know that y exists
+        const ykey = findRootTypeKey(parent)
+        encoding.writeVarUint(encoder, 1) // write parentYKey
+        encoding.writeVarString(encoder, ykey)
+      } else {
+        encoding.writeVarUint(encoder, 0) // write parent id
+        // @ts-ignore _item is defined because parent is integrated
+        writeID(encoder, parent._item.id)
+      }
+      if (parentSub !== null) {
+        encoding.writeVarString(encoder, parentSub)
+      }
+    }
+  }
+}
+
+/**
+ * @private
+ */
+export class AbstractItemRef extends AbstractStructRef {
+  /**
+   * @param {decoding.Decoder} decoder
+   * @param {ID} id
+   * @param {number} info
+   */
+  constructor (decoder, id, info) {
+    super(id)
+    /**
+     * The item that was originally to the left of this item.
+     * @type {ID | null}
+     */
+    this.left = (info & binary.BIT8) === binary.BIT8 ? readID(decoder) : null
+    /**
+     * The item that was originally to the right of this item.
+     * @type {ID | null}
+     */
+    this.right = (info & binary.BIT7) === binary.BIT7 ? readID(decoder) : null
+    const canCopyParentInfo = (info & (binary.BIT7 | binary.BIT8)) === 0
+    const hasParentYKey = canCopyParentInfo ? decoding.readVarUint(decoder) === 1 : 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}
+     */
+    this.parentYKey = canCopyParentInfo && hasParentYKey ? decoding.readVarString(decoder) : null
+    /**
+     * The parent type.
+     * @type {ID | null}
+     */
+    this.parent = canCopyParentInfo && !hasParentYKey ? readID(decoder) : null
+    /**
+     * 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 = canCopyParentInfo && (info & binary.BIT6) === binary.BIT6 ? decoding.readVarString(decoder) : null
+    const missing = this._missing
+    if (this.left !== null) {
+      missing.push(this.left)
+    }
+    if (this.right !== null) {
+      missing.push(this.right)
+    }
+    if (this.parent !== null) {
+      missing.push(this.parent)
+    }
+  }
+}
+
+/**
+ * @param {AbstractItemRef} item
+ * @param {number} offset
+ *
+ * @function
+ * @private
+ */
+export const changeItemRefOffset = (item, offset) => {
+  item.id = createID(item.id.client, item.id.clock + offset)
+  item.left = createID(item.id.client, item.id.clock - 1)
+}
+
+export class ItemParams {
+  /**
+   * @param {AbstractItem?} left
+   * @param {AbstractItem?} right
+   * @param {AbstractType<YEvent>?} parent
+   * @param {string|null} parentSub
+   */
+  constructor (left, right, parent, parentSub) {
+    this.left = left
+    this.right = right
+    this.parent = parent
+    this.parentSub = parentSub
+  }
+}
+
+/**
+ * Outsourcing some of the logic of computing the item params from a received struct.
+ * If parent === null, it is expected to gc the read struct. Otherwise apply it.
+ *
+ * @param {Transaction} transaction
+ * @param {StructStore} store
+ * @param {ID|null} leftid
+ * @param {ID|null} rightid
+ * @param {ID|null} parentid
+ * @param {string|null} parentSub
+ * @param {string|null} parentYKey
+ * @return {ItemParams}
+ *
+ * @private
+ * @function
+ */
+export const computeItemParams = (transaction, store, leftid, rightid, parentid, parentSub, parentYKey) => {
+  const left = leftid === null ? null : getItemCleanEnd(transaction, store, leftid)
+  const right = rightid === null ? null : getItemCleanStart(transaction, store, rightid)
+  let parent = null
+  if (parentid !== null) {
+    const parentItem = getItemType(store, parentid)
+    switch (parentItem.constructor) {
+      case ItemDeleted:
+      case GC:
+        break
+      default:
+        parent = parentItem.type
+    }
+  } else if (parentYKey !== null) {
+    parent = transaction.y.get(parentYKey)
+  } else if (left !== null) {
+    if (left.constructor !== GC) {
+      parent = left.parent
+      parentSub = left.parentSub
+    }
+  } else if (right !== null) {
+    if (right.constructor !== GC) {
+      parent = right.parent
+      parentSub = right.parentSub
+    }
+  } else {
+    throw error.unexpectedCase()
+  }
+  return new ItemParams(left, right, parent, parentSub)
+}

src/structs/AbstractStruct.js

@@ -0,0 +1,98 @@
+
+import {
+  Y, StructStore, ID, Transaction // eslint-disable-line
+} from '../internals.js'
+
+import * as encoding from 'lib0/encoding.js' // eslint-disable-line
+import * as error from 'lib0/error.js'
+
+/**
+ * @private
+ */
+export class AbstractStruct {
+  /**
+   * @param {ID} id
+   */
+  constructor (id) {
+    /**
+     * The uniqe identifier of this struct.
+     * @type {ID}
+     * @readonly
+     */
+    this.id = id
+    this.deleted = false
+  }
+  /**
+   * 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
+  }
+  /**
+   * @type {number}
+   */
+  get length () {
+    throw error.methodUnimplemented()
+  }
+  /**
+   * @param {encoding.Encoder} encoder The encoder to write data to.
+   * @param {number} offset
+   * @param {number} encodingRef
+   * @private
+   */
+  write (encoder, offset, encodingRef) {
+    throw error.methodUnimplemented()
+  }
+  /**
+   * @param {Transaction} transaction
+   */
+  integrate (transaction) {
+    throw error.methodUnimplemented()
+  }
+}
+
+/**
+ * @private
+ */
+export class AbstractStructRef {
+  /**
+   * @param {ID} id
+   */
+  constructor (id) {
+    /**
+     * @type {Array<ID>}
+     */
+    this._missing = []
+    /**
+     * The uniqe identifier of this type.
+     * @type {ID}
+     */
+    this.id = id
+  }
+  /**
+   * @param {Transaction} transaction
+   * @return {Array<ID|null>}
+   */
+  getMissing (transaction) {
+    return this._missing
+  }
+  /**
+   * @param {Transaction} transaction
+   * @param {StructStore} store
+   * @param {number} offset
+   * @return {AbstractStruct}
+   */
+  toStruct (transaction, store, offset) {
+    throw error.methodUnimplemented()
+  }
+  /**
+   * @type {number}
+   */
+  get length () {
+    return 1
+  }
+}

src/structs/GC.js

@@ -0,0 +1,105 @@
+
+import {
+  AbstractStructRef,
+  AbstractStruct,
+  createID,
+  addStruct,
+  Y, StructStore, Transaction, ID // eslint-disable-line
+} from '../internals.js'
+
+import * as decoding from 'lib0/decoding.js'
+import * as encoding from 'lib0/encoding.js'
+
+export const structGCRefNumber = 0
+
+/**
+ * @private
+ */
+export class GC extends AbstractStruct {
+  /**
+   * @param {ID} id
+   * @param {number} length
+   */
+  constructor (id, length) {
+    super(id)
+    /**
+     * @type {number}
+     */
+    this._len = length
+    this.deleted = true
+  }
+
+  get length () {
+    return this._len
+  }
+
+  delete () {}
+
+  /**
+   * @param {AbstractStruct} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    this._len += right.length
+    return true
+  }
+
+  /**
+   * @param {Transaction} transaction
+   */
+  integrate (transaction) {
+    addStruct(transaction.y.store, this)
+  }
+
+  /**
+   * @param {encoding.Encoder} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    encoding.writeUint8(encoder, structGCRefNumber)
+    encoding.writeVarUint(encoder, this._len - offset)
+  }
+}
+
+/**
+ * @private
+ */
+export class GCRef extends AbstractStructRef {
+  /**
+   * @param {decoding.Decoder} decoder
+   * @param {ID} id
+   * @param {number} info
+   */
+  constructor (decoder, id, info) {
+    super(id)
+    /**
+     * @type {number}
+     */
+    this._len = decoding.readVarUint(decoder)
+  }
+  get length () {
+    return this._len
+  }
+  missing () {
+    return [
+      createID(this.id.client, this.id.clock - 1)
+    ]
+  }
+  /**
+   * @param {Transaction} transaction
+   * @param {StructStore} store
+   * @param {number} offset
+   * @return {GC}
+   */
+  toStruct (transaction, store, offset) {
+    if (offset > 0) {
+      // @ts-ignore
+      this.id = createID(this.id.client, this.id.clock + offset)
+      this._len = this._len - offset
+    }
+    return new GC(
+      this.id,
+      this._len
+    )
+  }
+}

src/structs/ItemBinary.js

@@ -0,0 +1,98 @@
+
+import {
+  AbstractItem,
+  AbstractItemRef,
+  computeItemParams,
+  GC,
+  StructStore, Transaction, AbstractType, ID // eslint-disable-line
+} from '../internals.js'
+
+import * as encoding from 'lib0/encoding.js'
+import * as decoding from 'lib0/decoding.js'
+
+/**
+ * @private
+ */
+export const structBinaryRefNumber = 1
+
+/**
+ * @private
+ */
+export class ItemBinary extends AbstractItem {
+  /**
+   * @param {ID} id
+   * @param {AbstractItem | null} left
+   * @param {ID | null} origin
+   * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
+   * @param {AbstractType<any>} parent
+   * @param {string | null} parentSub
+   * @param {ArrayBuffer} content
+   */
+  constructor (id, left, origin, right, rightOrigin, parent, parentSub, content) {
+    super(id, left, origin, right, rightOrigin, parent, parentSub)
+    this.content = content
+  }
+  getContent () {
+    return [this.content]
+  }
+  /**
+   * @param {ID} id
+   * @param {AbstractItem | null} left
+   * @param {ID | null} origin
+   * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
+   * @param {AbstractType<any>} parent
+   * @param {string | null} parentSub
+   */
+  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
+    return new ItemBinary(id, left, origin, right, rightOrigin, parent, parentSub, this.content)
+  }
+  /**
+   * @param {encoding.Encoder} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    super.write(encoder, offset, structBinaryRefNumber)
+    encoding.writePayload(encoder, this.content)
+  }
+}
+
+/**
+ * @private
+ */
+export class ItemBinaryRef extends AbstractItemRef {
+  /**
+   * @param {decoding.Decoder} decoder
+   * @param {ID} id
+   * @param {number} info
+   */
+  constructor (decoder, id, info) {
+    super(decoder, id, info)
+    /**
+     * @type {ArrayBuffer}
+     */
+    this.content = decoding.readPayload(decoder)
+  }
+  /**
+   * @param {Transaction} transaction
+   * @param {StructStore} store
+   * @param {number} offset
+   * @return {ItemBinary|GC}
+   */
+  toStruct (transaction, store, offset) {
+    const { left, right, parent, parentSub } = computeItemParams(transaction, store, this.left, this.right, this.parent, this.parentSub, this.parentYKey)
+    return parent === null
+      ? new GC(this.id, this.length)
+      : new ItemBinary(
+        this.id,
+        left,
+        this.left,
+        right,
+        this.right,
+        parent,
+        parentSub,
+        this.content
+      )
+  }
+}

src/structs/ItemDeleted.js

@@ -0,0 +1,142 @@
+
+import {
+  AbstractItem,
+  AbstractItemRef,
+  computeItemParams,
+  changeItemRefOffset,
+  GC,
+  splitItem,
+  addToDeleteSet,
+  Y, StructStore, Transaction, ID, AbstractType // eslint-disable-line
+} from '../internals.js'
+
+import * as encoding from 'lib0/encoding.js'
+import * as decoding from 'lib0/decoding.js'
+
+/**
+ * @private
+ */
+export const structDeletedRefNumber = 2
+
+/**
+ * @private
+ */
+export class ItemDeleted extends AbstractItem {
+  /**
+   * @param {ID} id
+   * @param {AbstractItem | null} left
+   * @param {ID | null} origin
+   * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
+   * @param {AbstractType<any>} parent
+   * @param {string | null} parentSub
+   * @param {number} length
+   */
+  constructor (id, left, origin, right, rightOrigin, parent, parentSub, length) {
+    super(id, left, origin, right, rightOrigin, parent, parentSub)
+    this._len = length
+    this.deleted = true
+  }
+  get length () {
+    return this._len
+  }
+  /**
+   * @param {ID} id
+   * @param {AbstractItem | null} left
+   * @param {ID | null} origin
+   * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
+   * @param {AbstractType<any>} parent
+   * @param {string | null} parentSub
+   */
+  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
+    return new ItemDeleted(id, left, origin, right, rightOrigin, parent, parentSub, this.length)
+  }
+  /**
+   * @param {Transaction} transaction
+   */
+  integrate (transaction) {
+    super.integrate(transaction)
+    addToDeleteSet(transaction.deleteSet, this.id, this.length)
+  }
+  /**
+   * @param {Transaction} transaction
+   * @param {number} diff
+   */
+  splitAt (transaction, diff) {
+    /**
+     * @type {ItemDeleted}
+     */
+    // @ts-ignore
+    const right = splitItem(transaction, this, diff)
+    right._len -= diff
+    this._len = diff
+    return right
+  }
+  /**
+   * @param {ItemDeleted} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    if (super.mergeWith(right)) {
+      this._len += right._len
+      return true
+    }
+    return false
+  }
+  /**
+   * @param {encoding.Encoder} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    super.write(encoder, offset, structDeletedRefNumber)
+    encoding.writeVarUint(encoder, this.length - offset)
+  }
+}
+
+/**
+ * @private
+ */
+export class ItemDeletedRef extends AbstractItemRef {
+  /**
+   * @param {decoding.Decoder} decoder
+   * @param {ID} id
+   * @param {number} info
+   */
+  constructor (decoder, id, info) {
+    super(decoder, id, info)
+    /**
+     * @type {number}
+     */
+    this.len = decoding.readVarUint(decoder)
+  }
+  get length () {
+    return this.len
+  }
+  /**
+   * @param {Transaction} transaction
+   * @param {StructStore} store
+   * @param {number} offset
+   * @return {ItemDeleted|GC}
+   */
+  toStruct (transaction, store, offset) {
+    if (offset > 0) {
+      changeItemRefOffset(this, offset)
+      this.len = this.len - offset
+    }
+
+    const { left, right, parent, parentSub } = computeItemParams(transaction, store, this.left, this.right, this.parent, this.parentSub, this.parentYKey)
+    return parent === null
+      ? new GC(this.id, this.length)
+      : new ItemDeleted(
+        this.id,
+        left,
+        this.left,
+        right,
+        this.right,
+        parent,
+        parentSub,
+        this.len
+      )
+  }
+}

src/structs/ItemEmbed.js

@@ -0,0 +1,95 @@
+
+import {
+  AbstractItem,
+  AbstractItemRef,
+  computeItemParams,
+  GC,
+  Transaction, StructStore, ID, AbstractType // eslint-disable-line
+} from '../internals.js'
+
+import * as encoding from 'lib0/encoding.js'
+import * as decoding from 'lib0/decoding.js'
+
+/**
+ * @private
+ */
+export const structEmbedRefNumber = 3
+
+/**
+ * @private
+ */
+export class ItemEmbed extends AbstractItem {
+  /**
+   * @param {ID} id
+   * @param {AbstractItem | null} left
+   * @param {ID | null} origin
+   * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
+   * @param {AbstractType<any>} parent
+   * @param {string | null} parentSub
+   * @param {Object} embed
+   */
+  constructor (id, left, origin, right, rightOrigin, parent, parentSub, embed) {
+    super(id, left, origin, right, rightOrigin, parent, parentSub)
+    this.embed = embed
+  }
+  /**
+   * @param {ID} id
+   * @param {AbstractItem | null} left
+   * @param {ID | null} origin
+   * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
+   * @param {AbstractType<any>} parent
+   * @param {string | null} parentSub
+   */
+  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
+    return new ItemEmbed(id, left, origin, right, rightOrigin, parent, parentSub, this.embed)
+  }
+  /**
+   * @param {encoding.Encoder} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    super.write(encoder, offset, structEmbedRefNumber)
+    encoding.writeVarString(encoder, JSON.stringify(this.embed))
+  }
+}
+
+/**
+ * @private
+ */
+export class ItemEmbedRef extends AbstractItemRef {
+  /**
+   * @param {decoding.Decoder} decoder
+   * @param {ID} id
+   * @param {number} info
+   */
+  constructor (decoder, id, info) {
+    super(decoder, id, info)
+    /**
+     * @type {ArrayBuffer}
+     */
+    this.embed = JSON.parse(decoding.readVarString(decoder))
+  }
+  /**
+   * @param {Transaction} transaction
+   * @param {StructStore} store
+   * @param {number} offset
+   * @return {ItemEmbed|GC}
+   */
+  toStruct (transaction, store, offset) {
+    const { left, right, parent, parentSub } = computeItemParams(transaction, store, this.left, this.right, this.parent, this.parentSub, this.parentYKey)
+    return parent === null
+      ? new GC(this.id, this.length)
+      : new ItemEmbed(
+        this.id,
+        left,
+        this.left,
+        right,
+        this.right,
+        parent,
+        parentSub,
+        this.embed
+      )
+  }
+}

src/structs/ItemFormat.js

@@ -0,0 +1,103 @@
+
+import {
+  AbstractItem,
+  AbstractItemRef,
+  computeItemParams,
+  GC,
+  Transaction, StructStore, ID, AbstractType // eslint-disable-line
+} from '../internals.js'
+
+import * as encoding from 'lib0/encoding.js'
+import * as decoding from 'lib0/decoding.js'
+
+/**
+ * @private
+ */
+export const structFormatRefNumber = 4
+
+/**
+ * @private
+ */
+export class ItemFormat extends AbstractItem {
+  /**
+   * @param {ID} id
+   * @param {AbstractItem | null} left
+   * @param {ID | null} origin
+   * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
+   * @param {AbstractType<any>} parent
+   * @param {string | null} parentSub
+   * @param {string} key
+   * @param {any} value
+   */
+  constructor (id, left, origin, right, rightOrigin, parent, parentSub, key, value) {
+    super(id, left, origin, right, rightOrigin, parent, parentSub)
+    this.key = key
+    this.value = value
+  }
+  /**
+   * @param {ID} id
+   * @param {AbstractItem | null} left
+   * @param {ID | null} origin
+   * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
+   * @param {AbstractType<any>} parent
+   * @param {string | null} parentSub
+   */
+  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
+    return new ItemFormat(id, left, origin, right, rightOrigin, parent, parentSub, this.key, this.value)
+  }
+  get countable () {
+    return false
+  }
+  /**
+   * @param {encoding.Encoder} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    super.write(encoder, offset, structFormatRefNumber)
+    encoding.writeVarString(encoder, this.key)
+    encoding.writeVarString(encoder, JSON.stringify(this.value))
+  }
+}
+
+/**
+ * @private
+ */
+export class ItemFormatRef extends AbstractItemRef {
+  /**
+   * @param {decoding.Decoder} decoder
+   * @param {ID} id
+   * @param {number} info
+   */
+  constructor (decoder, id, info) {
+    super(decoder, id, info)
+    /**
+     * @type {string}
+     */
+    this.key = decoding.readVarString(decoder)
+    this.value = JSON.parse(decoding.readVarString(decoder))
+  }
+  /**
+   * @param {Transaction} transaction
+   * @param {StructStore} store
+   * @param {number} offset
+   * @return {ItemFormat|GC}
+   */
+  toStruct (transaction, store, offset) {
+    const { left, right, parent, parentSub } = computeItemParams(transaction, store, this.left, this.right, this.parent, this.parentSub, this.parentYKey)
+    return parent === null
+      ? new GC(this.id, this.length)
+      : new ItemFormat(
+        this.id,
+        left,
+        this.left,
+        right,
+        this.right,
+        parent,
+        parentSub,
+        this.key,
+        this.value
+      )
+  }
+}

src/structs/ItemJSON.js

@@ -0,0 +1,152 @@
+
+import {
+  AbstractItem,
+  AbstractItemRef,
+  computeItemParams,
+  splitItem,
+  changeItemRefOffset,
+  GC,
+  Transaction, StructStore, Y, ID, AbstractType // eslint-disable-line
+} from '../internals.js'
+
+import * as encoding from 'lib0/encoding.js'
+import * as decoding from 'lib0/decoding.js'
+
+/**
+ * @private
+ */
+export const structJSONRefNumber = 5
+
+/**
+ * @private
+ */
+export class ItemJSON extends AbstractItem {
+  /**
+   * @param {ID} id
+   * @param {AbstractItem | null} left
+   * @param {ID | null} origin
+   * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
+   * @param {AbstractType<any>} parent
+   * @param {string | null} parentSub
+   * @param {Array<any>} content
+   */
+  constructor (id, left, origin, right, rightOrigin, parent, parentSub, content) {
+    super(id, left, origin, right, rightOrigin, parent, parentSub)
+    /**
+     * @type {Array<any>}
+     */
+    this.content = content
+  }
+  /**
+   * @param {ID} id
+   * @param {AbstractItem | null} left
+   * @param {ID | null} origin
+   * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
+   * @param {AbstractType<any>} parent
+   * @param {string | null} parentSub
+   */
+  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
+    return new ItemJSON(id, left, origin, right, rightOrigin, parent, parentSub, this.content)
+  }
+  get length () {
+    return this.content.length
+  }
+  getContent () {
+    return this.content
+  }
+  /**
+   * @param {Transaction} transaction
+   * @param {number} diff
+   */
+  splitAt (transaction, diff) {
+    /**
+     * @type {ItemJSON}
+     */
+    // @ts-ignore
+    const right = splitItem(transaction, this, diff)
+    right.content = this.content.splice(diff)
+    return right
+  }
+  /**
+   * @param {ItemJSON} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    if (super.mergeWith(right)) {
+      this.content = this.content.concat(right.content)
+      return true
+    }
+    return false
+  }
+  /**
+   * @param {encoding.Encoder} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    super.write(encoder, offset, structJSONRefNumber)
+    const len = this.content.length
+    encoding.writeVarUint(encoder, len - offset)
+    for (let i = offset; i < len; i++) {
+      const c = this.content[i]
+      encoding.writeVarString(encoder, c === undefined ? 'undefined' : JSON.stringify(c))
+    }
+  }
+}
+
+/**
+ * @private
+ */
+export class ItemJSONRef extends AbstractItemRef {
+  /**
+   * @param {decoding.Decoder} decoder
+   * @param {ID} id
+   * @param {number} info
+   */
+  constructor (decoder, id, info) {
+    super(decoder, id, info)
+    const len = decoding.readVarUint(decoder)
+    const cs = []
+    for (let i = 0; i < len; i++) {
+      const c = decoding.readVarString(decoder)
+      if (c === 'undefined') {
+        cs.push(undefined)
+      } else {
+        cs.push(JSON.parse(c))
+      }
+    }
+    /**
+     * @type {Array<any>}
+     */
+    this.content = cs
+  }
+  get length () {
+    return this.content.length
+  }
+  /**
+   * @param {Transaction} transaction
+   * @param {StructStore} store
+   * @param {number} offset
+   * @return {ItemJSON|GC}
+   */
+  toStruct (transaction, store, offset) {
+    if (offset > 0) {
+      changeItemRefOffset(this, offset)
+      this.content = this.content.slice(offset)
+    }
+    const { left, right, parent, parentSub } = computeItemParams(transaction, store, this.left, this.right, this.parent, this.parentSub, this.parentYKey)
+    return parent === null
+      ? new GC(this.id, this.length)
+      : new ItemJSON(
+        this.id,
+        left,
+        this.left,
+        right,
+        this.right,
+        parent,
+        parentSub,
+        this.content
+      )
+  }
+}

src/structs/ItemString.js

@@ -0,0 +1,137 @@
+
+import {
+  AbstractItem,
+  AbstractItemRef,
+  computeItemParams,
+  splitItem,
+  changeItemRefOffset,
+  GC,
+  Transaction, StructStore, Y, ID, AbstractType // eslint-disable-line
+} from '../internals.js'
+
+import * as encoding from 'lib0/encoding.js'
+import * as decoding from 'lib0/decoding.js'
+
+export const structStringRefNumber = 6
+
+/**
+ * @private
+ */
+export class ItemString extends AbstractItem {
+  /**
+   * @param {ID} id
+   * @param {AbstractItem | null} left
+   * @param {ID | null} origin
+   * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
+   * @param {AbstractType<any>} parent
+   * @param {string | null} parentSub
+   * @param {string} string
+   */
+  constructor (id, left, origin, right, rightOrigin, parent, parentSub, string) {
+    super(id, left, origin, right, rightOrigin, parent, parentSub)
+    /**
+     * @type {string}
+     */
+    this.string = string
+  }
+  /**
+   * @param {ID} id
+   * @param {AbstractItem | null} left
+   * @param {ID | null} origin
+   * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
+   * @param {AbstractType<any>} parent
+   * @param {string | null} parentSub
+   */
+  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
+    return new ItemString(id, left, origin, right, rightOrigin, parent, parentSub, this.string)
+  }
+  getContent () {
+    return this.string.split('')
+  }
+  get length () {
+    return this.string.length
+  }
+  /**
+   * @param {Transaction} transaction
+   * @param {number} diff
+   * @return {ItemString}
+   */
+  splitAt (transaction, diff) {
+    /**
+     * @type {ItemString}
+     */
+    // @ts-ignore
+    const right = splitItem(transaction, this, diff)
+    right.string = this.string.slice(diff)
+    this.string = this.string.slice(0, diff)
+    return right
+  }
+  /**
+   * @param {ItemString} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    if (super.mergeWith(right)) {
+      this.string += right.string
+      return true
+    }
+    return false
+  }
+  /**
+   * @param {encoding.Encoder} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    super.write(encoder, offset, structStringRefNumber)
+    encoding.writeVarString(encoder, offset === 0 ? this.string : this.string.slice(offset))
+  }
+}
+
+/**
+ * @private
+ */
+export class ItemStringRef extends AbstractItemRef {
+  /**
+   * @param {decoding.Decoder} decoder
+   * @param {ID} id
+   * @param {number} info
+   */
+  constructor (decoder, id, info) {
+    super(decoder, id, info)
+    /**
+     * @type {string}
+     */
+    this.string = decoding.readVarString(decoder)
+  }
+  get length () {
+    return this.string.length
+  }
+  /**
+   * @param {Transaction} transaction
+   * @param {StructStore} store
+   * @param {number} offset
+   * @return {ItemString|GC}
+   */
+  toStruct (transaction, store, offset) {
+    if (offset > 0) {
+      changeItemRefOffset(this, offset)
+      this.string = this.string.slice(offset)
+    }
+
+    const { left, right, parent, parentSub } = computeItemParams(transaction, store, this.left, this.right, this.parent, this.parentSub, this.parentYKey)
+    return parent === null
+      ? new GC(this.id, this.length)
+      : new ItemString(
+        this.id,
+        left,
+        this.left,
+        right,
+        this.right,
+        parent,
+        parentSub,
+        this.string
+      )
+  }
+}

src/structs/ItemType.js

@@ -0,0 +1,178 @@
+
+import {
+  AbstractItem,
+  AbstractItemRef,
+  computeItemParams,
+  readYArray,
+  readYMap,
+  readYText,
+  readYXmlElement,
+  readYXmlFragment,
+  readYXmlHook,
+  readYXmlText,
+  StructStore, Y, GC, Transaction, ID, AbstractType // eslint-disable-line
+} from '../internals.js'
+
+import * as encoding from 'lib0/encoding.js' // eslint-disable-line
+import * as decoding from 'lib0/decoding.js'
+
+/**
+ * @private
+ */
+export const structTypeRefNumber = 7
+
+/**
+ * @type {Array<function(decoding.Decoder):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 ItemType extends AbstractItem {
+  /**
+   * @param {ID} id
+   * @param {AbstractItem | null} left
+   * @param {ID | null} origin
+   * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
+   * @param {AbstractType<any>} parent
+   * @param {string | null} parentSub
+   * @param {AbstractType<any>} type
+   */
+  constructor (id, left, origin, right, rightOrigin, parent, parentSub, type) {
+    super(id, left, origin, right, rightOrigin, parent, parentSub)
+    this.type = type
+  }
+
+  getContent () {
+    return [this.type]
+  }
+  /**
+   * @param {ID} id
+   * @param {AbstractItem | null} left
+   * @param {ID | null} origin
+   * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
+   * @param {AbstractType<any>} parent
+   * @param {string | null} parentSub
+   * @return {ItemType}
+   */
+  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
+    return new ItemType(id, left, origin, right, rightOrigin, parent, parentSub, this.type._copy())
+  }
+  /**
+   * @param {Transaction} transaction
+   */
+  integrate (transaction) {
+    super.integrate(transaction)
+    this.type._integrate(transaction.y, this)
+  }
+  /**
+   * @param {encoding.Encoder} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    super.write(encoder, offset, structTypeRefNumber)
+    this.type._write(encoder)
+  }
+  /**
+   * Mark this Item as deleted.
+   *
+   * @param {Transaction} transaction The Yjs instance
+   * @private
+   */
+  delete (transaction) {
+    super.delete(transaction)
+    transaction.changed.delete(this.type)
+    transaction.changedParentTypes.delete(this.type)
+    this.gcChildren(transaction, transaction.y.store)
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {StructStore} store
+   */
+  gcChildren (transaction, store) {
+    let item = this.type._start
+    while (item !== null) {
+      item.gc(transaction, store)
+      item = item.right
+    }
+    this.type._start = null
+    this.type._map.forEach(item => {
+      while (item !== null) {
+        item.gc(transaction, store)
+        // @ts-ignore
+        item = item.left
+      }
+    })
+    this._map = new Map()
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {StructStore} store
+   */
+  gc (transaction, store) {
+    super.gc(transaction, store)
+    this.gcChildren(transaction, store)
+  }
+}
+
+/**
+ * @private
+ */
+export class ItemTypeRef extends AbstractItemRef {
+  /**
+   * @param {decoding.Decoder} decoder
+   * @param {ID} id
+   * @param {number} info
+   */
+  constructor (decoder, id, info) {
+    super(decoder, id, info)
+    const typeRef = decoding.readVarUint(decoder)
+    /**
+     * @type {AbstractType<any>}
+     */
+    this.type = typeRefs[typeRef](decoder)
+  }
+  /**
+   * @param {Transaction} transaction
+   * @param {StructStore} store
+   * @param {number} offset
+   * @return {ItemType|GC}
+   */
+  toStruct (transaction, store, offset) {
+    const { left, right, parent, parentSub } = computeItemParams(transaction, store, this.left, this.right, this.parent, this.parentSub, this.parentYKey)
+    return parent === null
+      ? new GC(this.id, this.length)
+      : new ItemType(
+        this.id,
+        left,
+        this.left,
+        right,
+        this.right,
+        parent,
+        parentSub,
+        this.type
+      )
+  }
+}

src/types/AbstractType.js

@@ -0,0 +1,580 @@
+
+import {
+  removeEventHandlerListener,
+  callEventHandlerListeners,
+  addEventHandlerListener,
+  createEventHandler,
+  ItemType,
+  nextID,
+  isVisible,
+  ItemJSON,
+  ItemBinary,
+  createID,
+  getItemCleanStart,
+  Y, Snapshot, Transaction, EventHandler, YEvent, AbstractItem, // eslint-disable-line
+} from '../internals.js'
+
+import * as map from 'lib0/map.js'
+import * as iterator from 'lib0/iterator.js'
+import * as error from 'lib0/error.js'
+import * as encoding from 'lib0/encoding.js' // eslint-disable-line
+
+/**
+ * Call event listeners with an event. This will also add an event to all
+ * parents (for `.observeDeep` handlers).
+ * @private
+ *
+ * @template EventType
+ * @param {AbstractType<EventType>} type
+ * @param {Transaction} transaction
+ * @param {EventType} event
+ */
+export const callTypeObservers = (type, transaction, event) => {
+  callEventHandlerListeners(type._eH, event, transaction)
+  const changedParentTypes = transaction.changedParentTypes
+  while (true) {
+    // @ts-ignore
+    map.setIfUndefined(changedParentTypes, type, () => []).push(event)
+    if (type._item === null) {
+      break
+    }
+    type = type._item.parent
+  }
+}
+
+/**
+ * @template EventType
+ * Abstract Yjs Type class
+ */
+export class AbstractType {
+  constructor () {
+    /**
+     * @type {ItemType|null}
+     */
+    this._item = null
+    /**
+     * @private
+     * @type {Map<string,AbstractItem>}
+     */
+    this._map = new Map()
+    /**
+     * @private
+     * @type {AbstractItem|null}
+     */
+    this._start = null
+    /**
+     * @private
+     * @type {Y|null}
+     */
+    this._y = null
+    this._length = 0
+    /**
+     * Event handlers
+     * @type {EventHandler<EventType,Transaction>}
+     */
+    this._eH = createEventHandler()
+    /**
+     * Deep event handlers
+     * @type {EventHandler<Array<YEvent>,Transaction>}
+     */
+    this._dEH = createEventHandler()
+  }
+
+  /**
+   * 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 {Y} y The Yjs instance
+   * @param {ItemType|null} item
+   * @private
+   */
+  _integrate (y, item) {
+    this._y = y
+    this._item = item
+  }
+
+  /**
+   * @return {AbstractType<EventType>}
+   * @private
+   */
+  _copy () {
+    throw new Error('unimplemented')
+  }
+
+  /**
+   * @param {encoding.Encoder} encoder
+   * @private
+   */
+  _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.
+   *
+   * @private
+   */
+  _callObserver (transaction, parentSubs) { /* skip if no type is specified */ }
+
+  /**
+   * 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 {Object | Array | number | string}
+   */
+  toJSON () {}
+}
+
+/**
+ * @param {AbstractType<any>} type
+ * @return {Array<any>}
+ *
+ * @private
+ * @function
+ */
+export const typeArrayToArray = type => {
+  const cs = []
+  let n = type._start
+  while (n !== null) {
+    if (n.countable && !n.deleted) {
+      const c = n.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,AbstractType<any>):void} f A function to execute on every element of this YArray.
+ *
+ * @private
+ * @function
+ */
+export const typeArrayForEach = (type, f) => {
+  let index = 0
+  let n = type._start
+  while (n !== null) {
+    if (n.countable && !n.deleted) {
+      const c = n.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 typeArrayMap = (type, f) => {
+  /**
+   * @type {Array<any>}
+   */
+  const result = []
+  typeArrayForEach(type, (c, i) => {
+    result.push(f(c, i, type))
+  })
+  return result
+}
+
+/**
+ * @param {AbstractType<any>} type
+ * @return {IterableIterator<any>}
+ *
+ * @private
+ * @function
+ */
+export const typeArrayCreateIterator = 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
+        }
+      }
+      // currentContent could exist from the last iteration
+      if (currentContent === null) {
+        // we found n, so we can set currentContent
+        currentContent = n.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 typeArrayForEachSnapshot = (type, f, snapshot) => {
+  let index = 0
+  let n = type._start
+  while (n !== null) {
+    if (n.countable && isVisible(n, snapshot)) {
+      const c = n.getContent()
+      for (let i = 0; i < c.length; i++) {
+        f(c[i], index++, type)
+      }
+    }
+    n = n.right
+  }
+}
+
+/**
+ * @param {AbstractType<any>} type
+ * @param {number} index
+ * @return {any}
+ *
+ * @private
+ * @function
+ */
+export const typeArrayGet = (type, index) => {
+  for (let n = type._start; n !== null; n = n.right) {
+    if (!n.deleted && n.countable) {
+      if (index < n.length) {
+        return n.getContent()[index]
+      }
+      index -= n.length
+    }
+  }
+}
+
+/**
+ * @param {Transaction} transaction
+ * @param {AbstractType<any>} parent
+ * @param {AbstractItem?} referenceItem
+ * @param {Array<Object<string,any>|Array<any>|number|string|ArrayBuffer>} content
+ *
+ * @private
+ * @function
+ */
+export const typeArrayInsertGenericsAfter = (transaction, parent, referenceItem, content) => {
+  let left = referenceItem
+  const right = referenceItem === null ? parent._start : referenceItem.right
+  /**
+   * @type {Array<Object|Array|number>}
+   */
+  let jsonContent = []
+  const packJsonContent = () => {
+    if (jsonContent.length > 0) {
+      left = new ItemJSON(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, null, jsonContent)
+      left.integrate(transaction)
+      jsonContent = []
+    }
+  }
+  content.forEach(c => {
+    switch (c.constructor) {
+      case Number:
+      case Object:
+      case Array:
+      case String:
+        jsonContent.push(c)
+        break
+      default:
+        packJsonContent()
+        switch (c.constructor) {
+          case ArrayBuffer:
+            // @ts-ignore c is definitely an ArrayBuffer
+            left = new ItemBinary(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, null, c)
+            // @ts-ignore
+            left.integrate(transaction)
+            break
+          default:
+            if (c instanceof AbstractType) {
+              left = new ItemType(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, null, c)
+              left.integrate(transaction)
+            } else {
+              throw new Error('Unexpected content type in insert operation')
+            }
+        }
+    }
+  })
+  packJsonContent()
+}
+
+/**
+ * @param {Transaction} transaction
+ * @param {AbstractType<any>} parent
+ * @param {number} index
+ * @param {Array<Object<string,any>|Array<any>|number|string|ArrayBuffer>} content
+ *
+ * @private
+ * @function
+ */
+export const typeArrayInsertGenerics = (transaction, parent, index, content) => {
+  if (index === 0) {
+    return typeArrayInsertGenericsAfter(transaction, parent, null, content)
+  }
+  let n = parent._start
+  for (; n !== null; n = n.right) {
+    if (!n.deleted && n.countable) {
+      if (index <= n.length) {
+        if (index < n.length) {
+          // insert in-between
+          getItemCleanStart(transaction, transaction.y.store, createID(n.id.client, n.id.clock + index))
+        }
+        break
+      }
+      index -= n.length
+    }
+  }
+  return typeArrayInsertGenericsAfter(transaction, parent, n, content)
+}
+
+/**
+ * @param {Transaction} transaction
+ * @param {AbstractType<any>} parent
+ * @param {number} index
+ * @param {number} length
+ *
+ * @private
+ * @function
+ */
+export const typeArrayDelete = (transaction, parent, index, length) => {
+  if (length === 0) { return }
+  let n = parent._start
+  // compute the first item to be deleted
+  for (; n !== null; n = n.right) {
+    if (!n.deleted && n.countable) {
+      if (index <= n.length) {
+        if (index < n.length && index > 0) {
+          n = getItemCleanStart(transaction, transaction.y.store, createID(n.id.client, n.id.clock + index))
+        }
+        break
+      }
+      index -= n.length
+    }
+  }
+  // delete all items until done
+  while (length > 0 && n !== null) {
+    if (!n.deleted) {
+      if (length < n.length) {
+        getItemCleanStart(transaction, transaction.y.store, createID(n.id.client, n.id.clock + length))
+      }
+      n.delete(transaction)
+      length -= n.length
+    }
+    n = n.right
+  }
+  if (length > 0) {
+    throw error.create('array length exceeded')
+  }
+}
+
+/**
+ * @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|Array<any>|string|ArrayBuffer|AbstractType<any>} value
+ *
+ * @private
+ * @function
+ */
+export const typeMapSet = (transaction, parent, key, value) => {
+  const left = parent._map.get(key) || null
+  if (value == null) {
+    new ItemJSON(nextID(transaction), left, left === null ? null : left.lastId, null, null, parent, key, [value]).integrate(transaction)
+    return
+  }
+  switch (value.constructor) {
+    case Number:
+    case Object:
+    case Array:
+    case String:
+      new ItemJSON(nextID(transaction), left, left === null ? null : left.lastId, null, null, parent, key, [value]).integrate(transaction)
+      break
+    case ArrayBuffer:
+      new ItemBinary(nextID(transaction), left, left === null ? null : left.lastId, null, null, parent, key, value).integrate(transaction)
+      break
+    default:
+      if (value instanceof AbstractType) {
+        new ItemType(nextID(transaction), left, left === null ? null : left.lastId, null, null, parent, key, value).integrate(transaction)
+      } else {
+        throw new Error('Unexpected content type')
+      }
+  }
+}
+
+/**
+ * @param {AbstractType<any>} parent
+ * @param {string} key
+ * @return {Object<string,any>|number|Array<any>|string|ArrayBuffer|AbstractType<any>|undefined}
+ *
+ * @private
+ * @function
+ */
+export const typeMapGet = (parent, key) => {
+  const val = parent._map.get(key)
+  return val !== undefined && !val.deleted ? val.getContent()[0] : undefined
+}
+
+/**
+ * @param {AbstractType<any>} parent
+ * @return {Object<string,Object<string,any>|number|Array<any>|string|ArrayBuffer|AbstractType<any>|undefined>}
+ *
+ * @private
+ * @function
+ */
+export const typeMapGetAll = (parent) => {
+  /**
+   * @type {Object<string,any>}
+   */
+  let res = {}
+  for (const [key, value] of parent._map) {
+    if (!value.deleted) {
+      res[key] = value.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|Array<any>|string|ArrayBuffer|AbstractType<any>|undefined}
+ *
+ * @private
+ * @function
+ */
+export const typeMapGetSnapshot = (parent, key, snapshot) => {
+  let v = parent._map.get(key) || null
+  while (v !== null && (!snapshot.sm.has(v.id.client) || v.id.clock >= (snapshot.sm.get(v.id.client) || 0))) {
+    v = v.left
+  }
+  return v !== null && isVisible(v, snapshot) ? v.getContent()[v.length - 1] : undefined
+}
+
+/**
+ * @param {Map<string,AbstractItem>} map
+ * @return {IterableIterator<Array<any>>}
+ *
+ * @private
+ * @function
+ */
+export const createMapIterator = map => iterator.iteratorFilter(map.entries(), entry => !entry[1].deleted)

src/types/YArray.js

@@ -0,0 +1,213 @@
+/**
+ * @module YArray
+ */
+
+import {
+  YEvent,
+  AbstractType,
+  typeArrayGet,
+  typeArrayToArray,
+  typeArrayForEach,
+  typeArrayCreateIterator,
+  typeArrayInsertGenerics,
+  typeArrayDelete,
+  typeArrayMap,
+  YArrayRefID,
+  callTypeObservers,
+  transact,
+  Y, Transaction, ItemType, // eslint-disable-line
+} from '../internals.js'
+
+import * as decoding from 'lib0/decoding.js' // eslint-disable-line
+import * as encoding from 'lib0/encoding.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 {IterableIterator<T>}
+ */
+export class YArray extends AbstractType {
+  constructor () {
+    super()
+    /**
+     * @type {Array<any>?}
+     * @private
+     */
+    this._prelimContent = []
+  }
+  /**
+   * 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 {Y} y The Yjs instance
+   * @param {ItemType} item
+   *
+   * @private
+   */
+  _integrate (y, item) {
+    super._integrate(y, item)
+    // @ts-ignore
+    this.insert(0, this._prelimContent)
+    this._prelimContent = null
+  }
+  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.
+   *
+   * @private
+   */
+  _callObserver (transaction, parentSubs) {
+    callTypeObservers(this, transaction, new YArrayEvent(this, transaction))
+  }
+
+  /**
+   * 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 typeArrayGet(this, index)
+  }
+
+  /**
+   * Transforms this YArray to a JavaScript Array.
+   *
+   * @return {Array<T>}
+   */
+  toArray () {
+    return typeArrayToArray(this)
+  }
+
+  /**
+   * 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 T,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) {
+    // @ts-ignore
+    return typeArrayMap(this, f)
+  }
+
+  /**
+   * Executes a provided function on once on overy element of this YArray.
+   *
+   * @param {function(T,number):void} f A function to execute on every element of this YArray.
+   */
+  forEach (f) {
+    typeArrayForEach(this, f)
+  }
+
+  /**
+   * @return {IterableIterator<T>}
+   */
+  [Symbol.iterator] () {
+    return typeArrayCreateIterator(this)
+  }
+
+  /**
+   * 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._y !== null) {
+      transact(this._y, transaction => {
+        typeArrayDelete(transaction, this, index, length)
+      })
+    } else {
+      // @ts-ignore _prelimContent is defined because this is not yet integrated
+      this._prelimContent.splice(index, length)
+    }
+  }
+
+  /**
+   * 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 (this._y !== null) {
+      transact(this._y, transaction => {
+        typeArrayInsertGenerics(transaction, this, index, content)
+      })
+    } else {
+      // @ts-ignore _prelimContent is defined because this is not yet integrated
+      this._prelimContent.splice(index, 0, ...content)
+    }
+  }
+
+  /**
+   * Appends content to this YArray.
+   *
+   * @param {Array<T>} content Array of content to append.
+   */
+  push (content) {
+    this.insert(this.length, content)
+  }
+
+  /**
+   * @param {encoding.Encoder} encoder
+   * @private
+   */
+  _write (encoder) {
+    encoding.writeVarUint(encoder, YArrayRefID)
+  }
+}
+
+/**
+ * @param {decoding.Decoder} decoder
+ *
+ * @private
+ * @function
+ */
+export const readYArray = decoder => new YArray()

src/types/YMap.js

@@ -0,0 +1,202 @@
+
+/**
+ * @module YMap
+ */
+
+import {
+  YEvent,
+  AbstractType,
+  typeMapDelete,
+  typeMapSet,
+  typeMapGet,
+  typeMapHas,
+  createMapIterator,
+  YMapRefID,
+  callTypeObservers,
+  transact,
+  Y, Transaction, ItemType, // eslint-disable-line
+} from '../internals.js'
+
+import * as encoding from 'lib0/encoding.js'
+import * as decoding from 'lib0/decoding.js' // eslint-disable-line
+import * as iterator from 'lib0/iterator.js'
+
+/**
+ * @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 T number|string|Object|Array|ArrayBuffer
+ * A shared Map implementation.
+ *
+ * @extends AbstractType<YMapEvent<T>>
+ * @implements {IterableIterator}
+ */
+export class YMap extends AbstractType {
+  constructor () {
+    super()
+    /**
+     * @type {Map<string,any>?}
+     * @private
+     */
+    this._prelimContent = new Map()
+  }
+  /**
+   * 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 {Y} y The Yjs instance
+   * @param {ItemType} item
+   *
+   * @private
+   */
+  _integrate (y, item) {
+    super._integrate(y, item)
+    // @ts-ignore
+    for (let [key, value] of this._prelimContent) {
+      this.set(key, value)
+    }
+    this._prelimContent = null
+  }
+  /**
+   * Creates YMapEvent and calls observers.
+   *
+   * @param {Transaction} transaction
+   * @param {Set<null|string>} parentSubs Keys changed on this type. `null` if list was modified.
+   *
+   * @private
+   */
+  _callObserver (transaction, parentSubs) {
+    callTypeObservers(this, transaction, new YMapEvent(this, transaction, parentSubs))
+  }
+
+  /**
+   * Transforms this Shared Type to a JSON object.
+   *
+   * @return {Object<string,T>}
+   */
+  toJSON () {
+    /**
+     * @type {Object<string,T>}
+     */
+    const map = {}
+    for (let [key, item] of this._map) {
+      if (!item.deleted) {
+        const v = item.getContent()[0]
+        map[key] = v instanceof AbstractType ? v.toJSON() : v
+      }
+    }
+    return map
+  }
+
+  /**
+   * Returns the keys for each element in the YMap Type.
+   *
+   * @return {Iterator<string>}
+   */
+  keys () {
+    return iterator.iteratorMap(createMapIterator(this._map), v => v[0])
+  }
+  /**
+   * Returns the value for each element in the YMap Type.
+   *
+   * @return {IterableIterator<T>}
+   */
+  entries () {
+    return iterator.iteratorMap(createMapIterator(this._map), v => v[1].getContent()[0])
+  }
+
+  /**
+   * @return {IterableIterator<T>}
+   */
+  [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._y !== null) {
+      transact(this._y, transaction => {
+        typeMapDelete(transaction, this, key)
+      })
+    } else {
+      // @ts-ignore
+      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 {T} value The value of the element to add
+   */
+  set (key, value) {
+    if (this._y !== null) {
+      transact(this._y, transaction => {
+        typeMapSet(transaction, this, key, value)
+      })
+    } else {
+      // @ts-ignore
+      this._prelimContent.set(key, value)
+    }
+    return value
+  }
+
+  /**
+   * Returns a specified element from this YMap.
+   *
+   * @param {string} key
+   * @return {T|undefined}
+   */
+  get (key) {
+    // @ts-ignore
+    return 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)
+  }
+
+  /**
+   * @param {encoding.Encoder} encoder
+   *
+   * @private
+   */
+  _write (encoder) {
+    encoding.writeVarUint(encoder, YMapRefID)
+  }
+}
+
+/**
+ * @param {decoding.Decoder} decoder
+ *
+ * @private
+ * @function
+ */
+export const readYMap = decoder => new YMap()

src/types/YText.js

@@ -0,0 +1,929 @@
+
+/**
+ * @module YText
+ */
+
+import {
+  YEvent,
+  ItemEmbed,
+  ItemString,
+  ItemFormat,
+  AbstractType,
+  nextID,
+  createID,
+  getItemCleanStart,
+  isVisible,
+  YTextRefID,
+  callTypeObservers,
+  transact,
+  Y, ItemType, AbstractItem, Snapshot, StructStore, Transaction // eslint-disable-line
+} from '../internals.js'
+
+import * as decoding from 'lib0/decoding.js' // eslint-disable-line
+import * as encoding from 'lib0/encoding.js'
+
+export class ItemListPosition {
+  /**
+   * @param {AbstractItem|null} left
+   * @param {AbstractItem|null} right
+   */
+  constructor (left, right) {
+    this.left = left
+    this.right = right
+  }
+}
+
+export class ItemTextListPosition extends ItemListPosition {
+  /**
+   * @param {AbstractItem|null} left
+   * @param {AbstractItem|null} right
+   * @param {Map<string,any>} currentAttributes
+   */
+  constructor (left, right, currentAttributes) {
+    super(left, right)
+    this.currentAttributes = currentAttributes
+  }
+}
+
+export class ItemInsertionResult extends ItemListPosition {
+  /**
+   * @param {AbstractItem|null} left
+   * @param {AbstractItem|null} right
+   * @param {Map<string,any>} negatedAttributes
+   */
+  constructor (left, right, negatedAttributes) {
+    super(left, right)
+    this.negatedAttributes = negatedAttributes
+  }
+}
+
+/**
+ * @param {Transaction} transaction
+ * @param {StructStore} store
+ * @param {Map<string,any>} currentAttributes
+ * @param {AbstractItem|null} left
+ * @param {AbstractItem|null} right
+ * @param {number} count
+ * @return {ItemTextListPosition}
+ *
+ * @private
+ * @function
+ */
+const findNextPosition = (transaction, store, currentAttributes, left, right, count) => {
+  while (right !== null && count > 0) {
+    switch (right.constructor) {
+      case ItemEmbed:
+      case ItemString:
+        if (!right.deleted) {
+          if (count < right.length) {
+            // split right
+            getItemCleanStart(transaction, store, createID(right.id.client, right.id.clock + count))
+          }
+          count -= right.length
+        }
+        break
+      case ItemFormat:
+        if (!right.deleted) {
+          // @ts-ignore right is ItemFormat
+          updateCurrentAttributes(currentAttributes, right)
+        }
+        break
+    }
+    left = right
+    right = right.right
+  }
+  return new ItemTextListPosition(left, right, currentAttributes)
+}
+
+/**
+ * @param {Transaction} transaction
+ * @param {StructStore} store
+ * @param {AbstractType<any>} parent
+ * @param {number} index
+ * @return {ItemTextListPosition}
+ *
+ * @private
+ * @function
+ */
+const findPosition = (transaction, store, parent, index) => {
+  let currentAttributes = new Map()
+  let left = null
+  let right = parent._start
+  return findNextPosition(transaction, store, currentAttributes, left, right, index)
+}
+
+/**
+ * Negate applied formats
+ *
+ * @param {Transaction} transaction
+ * @param {AbstractType<any>} parent
+ * @param {AbstractItem|null} left
+ * @param {AbstractItem|null} right
+ * @param {Map<string,any>} negatedAttributes
+ * @return {ItemListPosition}
+ *
+ * @private
+ * @function
+ */
+const insertNegatedAttributes = (transaction, parent, left, right, negatedAttributes) => {
+  // check if we really need to remove attributes
+  while (
+    right !== null && (
+      right.deleted === true || (
+        right.constructor === ItemFormat &&
+        // @ts-ignore right is ItemFormat
+        (negatedAttributes.get(right.key) === right.value)
+      )
+    )
+  ) {
+    if (!right.deleted) {
+      // @ts-ignore right is ItemFormat
+      negatedAttributes.delete(right.key)
+    }
+    left = right
+    right = right.right
+  }
+  for (let [key, val] of negatedAttributes) {
+    left = new ItemFormat(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, null, key, val)
+    left.integrate(transaction)
+  }
+  return {left, right}
+}
+
+/**
+ * @param {Map<string,any>} currentAttributes
+ * @param {ItemFormat} item
+ *
+ * @private
+ * @function
+ */
+const updateCurrentAttributes = (currentAttributes, item) => {
+  const value = item.value
+  const key = item.key
+  if (value === null) {
+    currentAttributes.delete(key)
+  } else {
+    currentAttributes.set(key, value)
+  }
+}
+
+/**
+ * @param {AbstractItem|null} left
+ * @param {AbstractItem|null} right
+ * @param {Map<string,any>} currentAttributes
+ * @param {Object<string,any>} attributes
+ * @return {ItemListPosition}
+ *
+ * @private
+ * @function
+ */
+const minimizeAttributeChanges = (left, right, currentAttributes, attributes) => {
+  // go right while attributes[right.key] === right.value (or right is deleted)
+  while (true) {
+    if (right === null) {
+      break
+    } else if (right.deleted) {
+      // continue
+    // @ts-ignore right is ItemFormat
+    } else if (right.constructor === ItemFormat && (attributes[right.key] || null) === right.value) {
+      // found a format, update currentAttributes and continue
+      // @ts-ignore right is ItemFormat
+      updateCurrentAttributes(currentAttributes, right)
+    } else {
+      break
+    }
+    left = right
+    right = right.right
+  }
+  return new ItemListPosition(left, right)
+}
+
+/**
+ * @param {Transaction} transaction
+ * @param {AbstractType<any>} parent
+ * @param {AbstractItem|null} left
+ * @param {AbstractItem|null} right
+ * @param {Map<string,any>} currentAttributes
+ * @param {Object<string,any>} attributes
+ * @return {ItemInsertionResult}
+ *
+ * @private
+ * @function
+ **/
+const insertAttributes = (transaction, parent, left, right, currentAttributes, attributes) => {
+  const negatedAttributes = new Map()
+  // insert format-start items
+  for (let key in attributes) {
+    const val = attributes[key]
+    const currentVal = currentAttributes.get(key)
+    if (currentVal !== val) {
+      // save negated attribute (set null if currentVal undefined)
+      negatedAttributes.set(key, currentVal || null)
+      left = new ItemFormat(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, null, key, val)
+      left.integrate(transaction)
+    }
+  }
+  return new ItemInsertionResult(left, right, negatedAttributes)
+}
+
+/**
+ * @param {Transaction} transaction
+ * @param {AbstractType<any>} parent
+ * @param {AbstractItem|null} left
+ * @param {AbstractItem|null} right
+ * @param {Map<string,any>} currentAttributes
+ * @param {string} text
+ * @param {Object<string,any>} attributes
+ * @return {ItemListPosition}
+ *
+ * @private
+ * @function
+ **/
+const insertText = (transaction, parent, left, right, currentAttributes, text, attributes) => {
+  for (let [key] of currentAttributes) {
+    if (attributes[key] === undefined) {
+      attributes[key] = null
+    }
+  }
+  const minPos = minimizeAttributeChanges(left, right, currentAttributes, attributes)
+  const insertPos = insertAttributes(transaction, parent, minPos.left, minPos.right, currentAttributes, attributes)
+  left = insertPos.left
+  right = insertPos.right
+  // insert content
+  if (text.constructor === String) {
+    left = new ItemString(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, null, text)
+  } else {
+    left = new ItemEmbed(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, null, text)
+  }
+  left.integrate(transaction)
+  return insertNegatedAttributes(transaction, parent, left, insertPos.right, insertPos.negatedAttributes)
+}
+
+/**
+ * @param {Transaction} transaction
+ * @param {AbstractType<any>} parent
+ * @param {AbstractItem|null} left
+ * @param {AbstractItem|null} right
+ * @param {Map<string,any>} currentAttributes
+ * @param {number} length
+ * @param {Object<string,any>} attributes
+ * @return {ItemListPosition}
+ *
+ * @private
+ * @function
+ */
+const formatText = (transaction, parent, left, right, currentAttributes, length, attributes) => {
+  const minPos = minimizeAttributeChanges(left, right, currentAttributes, attributes)
+  const insertPos = insertAttributes(transaction, parent, minPos.left, minPos.right, currentAttributes, attributes)
+  const negatedAttributes = insertPos.negatedAttributes
+  left = insertPos.left
+  right = insertPos.right
+  // iterate until first non-format or null is found
+  // delete all formats with attributes[format.key] != null
+  while (length > 0 && right !== null) {
+    if (right.deleted === false) {
+      switch (right.constructor) {
+        case ItemFormat:
+          // @ts-ignore right is ItemFormat
+          const attr = attributes[right.key]
+          if (attr !== undefined) {
+            // @ts-ignore right is ItemFormat
+            if (attr === right.value) {
+              // @ts-ignore right is ItemFormat
+              negatedAttributes.delete(right.key)
+            } else {
+              // @ts-ignore right is ItemFormat
+              negatedAttributes.set(right.key, right.value)
+            }
+            right.delete(transaction)
+          }
+          // @ts-ignore right is ItemFormat
+          updateCurrentAttributes(currentAttributes, right)
+          break
+        case ItemEmbed:
+        case ItemString:
+          if (length < right.length) {
+            getItemCleanStart(transaction, transaction.y.store, createID(right.id.client, right.id.clock + length))
+          }
+          length -= right.length
+          break
+      }
+    }
+    left = right
+    right = right.right
+  }
+  return insertNegatedAttributes(transaction, parent, left, right, negatedAttributes)
+}
+
+/**
+ * @param {Transaction} transaction
+ * @param {AbstractItem|null} left
+ * @param {AbstractItem|null} right
+ * @param {Map<string,any>} currentAttributes
+ * @param {number} length
+ * @return {ItemListPosition}
+ *
+ * @private
+ * @function
+ */
+const deleteText = (transaction, left, right, currentAttributes, length) => {
+  while (length > 0 && right !== null) {
+    if (right.deleted === false) {
+      switch (right.constructor) {
+        case ItemFormat:
+          // @ts-ignore right is ItemFormat
+          updateCurrentAttributes(currentAttributes, right)
+          break
+        case ItemEmbed:
+        case ItemString:
+          if (length < right.length) {
+            getItemCleanStart(transaction, transaction.y.store, createID(right.id.client, right.id.clock + length))
+          }
+          length -= right.length
+          right.delete(transaction)
+          break
+      }
+    }
+    left = right
+    right = right.right
+  }
+  return { left, right }
+}
+
+/**
+ * The Quill Delta format represents changes on a text document with
+ * formatting information. For mor information visit {@link https://quilljs.com/docs/delta/|Quill Delta}
+ *
+ * @example
+ *   {
+ *     ops: [
+ *       { insert: 'Gandalf', attributes: { bold: true } },
+ *       { insert: ' the ' },
+ *       { insert: 'Grey', attributes: { color: '#cccccc' } }
+ *     ]
+ *   }
+ *
+ */
+
+/**
+  * Attributes that can be assigned to a selection of text.
+  *
+  * @example
+  *   {
+  *     bold: true,
+  *     font-size: '40px'
+  *   }
+  *
+  * @typedef {Object} TextAttributes
+  */
+
+/**
+ * @typedef {Object} DeltaItem
+ * @property {number|undefined} DeltaItem.delete
+ * @property {number|undefined} DeltaItem.retain
+ * @property {string|undefined} DeltaItem.string
+ * @property {Object<string,any>} DeltaItem.attributes
+ */
+
+/**
+ * Event that describes the changes on a YText type.
+ */
+class YTextEvent extends YEvent {
+  /**
+   * @param {YText} ytext
+   * @param {Transaction} transaction
+   */
+  constructor (ytext, transaction) {
+    super(ytext, transaction)
+    /**
+     * @private
+     * @type {Array<DeltaItem>|null}
+     */
+    this._delta = null
+  }
+  /**
+   * Compute the changes in the delta format.
+   * A {@link https://quilljs.com/docs/delta/|Quill Delta}) that represents the changes on the document.
+   *
+   * @type {Array<DeltaItem>}
+   *
+   * @public
+   */
+  get delta () {
+    if (this._delta === null) {
+      const y = this.target._y
+      // @ts-ignore
+      transact(y, transaction => {
+        /**
+         * @type {Array<DeltaItem>}
+         */
+        const delta = []
+        const currentAttributes = new Map() // saves all current attributes for insert
+        const oldAttributes = new Map()
+        let item = this.target._start
+        /**
+         * @type {string?}
+         */
+        let action = null
+        /**
+         * @type {Object<string,any>}
+         */
+        let attributes = {} // counts added or removed new attributes for retain
+        let insert = ''
+        let retain = 0
+        let deleteLen = 0
+        this._delta = delta
+        const addOp = () => {
+          if (action !== null) {
+            /**
+             * @type {any}
+             */
+            let op
+            switch (action) {
+              case 'delete':
+                op = { delete: deleteLen }
+                deleteLen = 0
+                break
+              case 'insert':
+                op = { insert }
+                if (currentAttributes.size > 0) {
+                  op.attributes = {}
+                  for (let [key, value] of currentAttributes) {
+                    if (value !== null) {
+                      op.attributes[key] = value
+                    }
+                  }
+                }
+                insert = ''
+                break
+              case 'retain':
+                op = { retain }
+                if (Object.keys(attributes).length > 0) {
+                  op.attributes = {}
+                  for (let key in attributes) {
+                    op.attributes[key] = attributes[key]
+                  }
+                }
+                retain = 0
+                break
+            }
+            delta.push(op)
+            action = null
+          }
+        }
+        while (item !== null) {
+          switch (item.constructor) {
+            case ItemEmbed:
+              if (this.adds(item)) {
+                addOp()
+                action = 'insert'
+                // @ts-ignore item is ItemFormat
+                insert = item.embed
+                addOp()
+              } else if (this.deletes(item)) {
+                if (action !== 'delete') {
+                  addOp()
+                  action = 'delete'
+                }
+                deleteLen += 1
+              } else if (!item.deleted) {
+                if (action !== 'retain') {
+                  addOp()
+                  action = 'retain'
+                }
+                retain += 1
+              }
+              break
+            case ItemString:
+              if (this.adds(item)) {
+                if (action !== 'insert') {
+                  addOp()
+                  action = 'insert'
+                }
+                // @ts-ignore
+                insert += item.string
+              } else if (this.deletes(item)) {
+                if (action !== 'delete') {
+                  addOp()
+                  action = 'delete'
+                }
+                deleteLen += item.length
+              } else if (!item.deleted) {
+                if (action !== 'retain') {
+                  addOp()
+                  action = 'retain'
+                }
+                retain += item.length
+              }
+              break
+            case ItemFormat:
+              if (this.adds(item)) {
+                // @ts-ignore item is ItemFormat
+                const curVal = currentAttributes.get(item.key) || null
+                // @ts-ignore item is ItemFormat
+                if (curVal !== item.value) {
+                  if (action === 'retain') {
+                    addOp()
+                  }
+                  // @ts-ignore item is ItemFormat
+                  if (item.value === (oldAttributes.get(item.key) || null)) {
+                    // @ts-ignore item is ItemFormat
+                    delete attributes[item.key]
+                  } else {
+                    // @ts-ignore item is ItemFormat
+                    attributes[item.key] = item.value
+                  }
+                } else {
+                  item.delete(transaction)
+                }
+              } else if (this.deletes(item)) {
+                // @ts-ignore item is ItemFormat
+                oldAttributes.set(item.key, item.value)
+                // @ts-ignore item is ItemFormat
+                const curVal = currentAttributes.get(item.key) || null
+                // @ts-ignore item is ItemFormat
+                if (curVal !== item.value) {
+                  if (action === 'retain') {
+                    addOp()
+                  }
+                  // @ts-ignore item is ItemFormat
+                  attributes[item.key] = curVal
+                }
+              } else if (!item.deleted) {
+                // @ts-ignore item is ItemFormat
+                oldAttributes.set(item.key, item.value)
+                // @ts-ignore item is ItemFormat
+                const attr = attributes[item.key]
+                if (attr !== undefined) {
+                  // @ts-ignore item is ItemFormat
+                  if (attr !== item.value) {
+                    if (action === 'retain') {
+                      addOp()
+                    }
+                    // @ts-ignore item is ItemFormat
+                    if (item.value === null) {
+                      // @ts-ignore item is ItemFormat
+                      attributes[item.key] = item.value
+                    } else {
+                      // @ts-ignore item is ItemFormat
+                      delete attributes[item.key]
+                    }
+                  } else {
+                    item.delete(transaction)
+                  }
+                }
+              }
+              if (!item.deleted) {
+                if (action === 'insert') {
+                  addOp()
+                }
+                // @ts-ignore item is ItemFormat
+                updateCurrentAttributes(currentAttributes, item)
+              }
+              break
+          }
+          item = item.right
+        }
+        addOp()
+        while (this._delta.length > 0) {
+          let lastOp = this._delta[this._delta.length - 1]
+          if (lastOp.retain !== undefined && lastOp.attributes === undefined) {
+            // retain delta's if they don't assign attributes
+            this._delta.pop()
+          } else {
+            break
+          }
+        }
+      })
+    }
+    // @ts-ignore _delta is defined above
+    return this._delta
+  }
+}
+
+/**
+ * Type that represents text with formatting information.
+ *
+ * This type replaces y-richtext as this implementation is able to handle
+ * block formats (format information on a paragraph), embeds (complex elements
+ * like pictures and videos), and text formats (**bold**, *italic*).
+ *
+ * @extends AbstractType<YTextEvent>
+ */
+export class YText extends AbstractType {
+  /**
+   * @param {String} [string] The initial value of the YText.
+   */
+  constructor (string) {
+    super()
+    /**
+     * @type {Array<string>?}
+     * @private
+     */
+    this._prelimContent = string !== undefined ? [string] : []
+  }
+
+  get length () {
+    return this._length
+  }
+
+  /**
+   * @param {Y} y
+   * @param {ItemType} item
+   *
+   * @private
+   */
+  _integrate (y, item) {
+    super._integrate(y, item)
+    // @ts-ignore this._prelimContent is still defined
+    this.insert(0, this._prelimContent.join(''))
+    this._prelimContent = null
+  }
+
+  /**
+   * Creates YTextEvent and calls observers.
+   *
+   * @param {Transaction} transaction
+   * @param {Set<null|string>} parentSubs Keys changed on this type. `null` if list was modified.
+   *
+   * @private
+   */
+  _callObserver (transaction, parentSubs) {
+    callTypeObservers(this, transaction, new YTextEvent(this, transaction))
+  }
+
+  toDom () {
+    return document.createTextNode(this.toString())
+  }
+
+  /**
+   * Returns the unformatted string representation of this YText type.
+   *
+   * @public
+   */
+  toString () {
+    let str = ''
+    /**
+     * @type {AbstractItem|null}
+     */
+    let n = this._start
+    while (n !== null) {
+      if (!n.deleted && n.countable && n.constructor === ItemString) {
+        // @ts-ignore
+        str += n.string
+      }
+      n = n.right
+    }
+    return str
+  }
+
+  toDomString () {
+    // @ts-ignore
+    return this.toDelta().map(delta => {
+      const nestedNodes = []
+      for (let nodeName in delta.attributes) {
+        const attrs = []
+        for (let 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[i]
+          str += ` ${attr.key}="${attr.value}"`
+        }
+        str += '>'
+      }
+      str += delta.insert
+      for (let i = nestedNodes.length - 1; i >= 0; i--) {
+        str += `</${nestedNodes[i].nodeName}>`
+      }
+      return str
+    })
+  }
+
+  /**
+   * Apply a {@link Delta} on this shared YText type.
+   *
+   * @param {any} delta The changes to apply on this element.
+   *
+   * @public
+   */
+  applyDelta (delta) {
+    if (this._y !== null) {
+      transact(this._y, transaction => {
+        /**
+         * @type {ItemListPosition}
+         */
+        let pos = new ItemListPosition(null, this._start)
+        const currentAttributes = new Map()
+        for (let i = 0; i < delta.length; i++) {
+          const op = delta[i]
+          if (op.insert !== undefined) {
+            pos = insertText(transaction, this, pos.left, pos.right, currentAttributes, op.insert, op.attributes || {})
+          } else if (op.retain !== undefined) {
+            pos = formatText(transaction, this, pos.left, pos.right, currentAttributes, op.retain, op.attributes || {})
+          } else if (op.delete !== undefined) {
+            pos = deleteText(transaction, pos.left, pos.right, currentAttributes, op.delete)
+          }
+        }
+      })
+    }
+  }
+
+  /**
+   * Returns the Delta representation of this YText type.
+   *
+   * @param {Snapshot} [snapshot]
+   * @param {Snapshot} [prevSnapshot]
+   * @return {any} The Delta representation of this type.
+   *
+   * @public
+   */
+  toDelta (snapshot, prevSnapshot) {
+    /**
+     * @type{Array<any>}
+     */
+    const ops = []
+    const currentAttributes = new Map()
+    let str = ''
+    /**
+     * @type {AbstractItem|null}
+     */
+    // @ts-ignore
+    let n = this._start
+    function packStr () {
+      if (str.length > 0) {
+        // pack str with attributes to ops
+        /**
+         * @type {Object<string,any>}
+         */
+        const attributes = {}
+        let addAttributes = false
+        for (let [key, value] of currentAttributes) {
+          addAttributes = true
+          attributes[key] = value
+        }
+        /**
+         * @type {Object<string,any>}
+         */
+        const op = { insert: str }
+        if (addAttributes) {
+          op.attributes = attributes
+        }
+        ops.push(op)
+        str = ''
+      }
+    }
+    while (n !== null) {
+      if (isVisible(n, snapshot) || (prevSnapshot !== undefined && isVisible(n, prevSnapshot))) {
+        switch (n.constructor) {
+          case ItemString:
+            const cur = currentAttributes.get('ychange')
+            if (snapshot !== undefined && !isVisible(n, snapshot)) {
+              if (cur === undefined || cur.user !== n.id.client || cur.state !== 'removed') {
+                packStr()
+                currentAttributes.set('ychange', { user: n.id.client, state: 'removed' })
+              }
+            } else if (prevSnapshot !== undefined && !isVisible(n, prevSnapshot)) {
+              if (cur === undefined || cur.user !== n.id.client || cur.state !== 'added') {
+                packStr()
+                currentAttributes.set('ychange', { user: n.id.client, state: 'added' })
+              }
+            } else if (cur !== undefined) {
+              packStr()
+              currentAttributes.delete('ychange')
+            }
+            // @ts-ignore
+            str += n.string
+            break
+          case ItemFormat:
+            packStr()
+            // @ts-ignore
+            updateCurrentAttributes(currentAttributes, n)
+            break
+        }
+      }
+      n = n.right
+    }
+    packStr()
+    return ops
+  }
+
+  /**
+   * Insert text at a given index.
+   *
+   * @param {number} index The index at which to start inserting.
+   * @param {String} text The text to insert at the specified position.
+   * @param {TextAttributes} attributes Optionally define some formatting
+   *                                    information to apply on the inserted
+   *                                    Text.
+   * @public
+   */
+  insert (index, text, attributes = {}) {
+    if (text.length <= 0) {
+      return
+    }
+    const y = this._y
+    if (y !== null) {
+      transact(y, transaction => {
+        const {left, right, currentAttributes} = findPosition(transaction, y.store, this, index)
+        insertText(transaction, this, left, right, currentAttributes, text, attributes)
+      })
+    }
+  }
+
+  /**
+   * Inserts an embed at a index.
+   *
+   * @param {number} index The index to insert the embed at.
+   * @param {Object} embed The Object that represents the embed.
+   * @param {TextAttributes} attributes Attribute information to apply on the
+   *                                    embed
+   *
+   * @public
+   */
+  insertEmbed (index, embed, attributes = {}) {
+    if (embed.constructor !== Object) {
+      throw new Error('Embed must be an Object')
+    }
+    const y = this._y
+    if (y !== null) {
+      transact(y, transaction => {
+        const { left, right, currentAttributes } = findPosition(transaction, y.store, this, index)
+        insertText(transaction, this, left, right, currentAttributes, embed, attributes)
+      })
+    }
+  }
+
+  /**
+   * Deletes text starting from an index.
+   *
+   * @param {number} index Index at which to start deleting.
+   * @param {number} length The number of characters to remove. Defaults to 1.
+   *
+   * @public
+   */
+  delete (index, length) {
+    if (length === 0) {
+      return
+    }
+    const y = this._y
+    if (y !== null) {
+      transact(y, transaction => {
+        const { left, right, currentAttributes } = findPosition(transaction, y.store, this, index)
+        deleteText(transaction, left, right, currentAttributes, length)
+      })
+    }
+  }
+
+  /**
+   * Assigns properties to a range of text.
+   *
+   * @param {number} index The position where to start formatting.
+   * @param {number} length The amount of characters to assign properties to.
+   * @param {TextAttributes} attributes Attribute information to apply on the
+   *                                    text.
+   *
+   * @public
+   */
+  format (index, length, attributes) {
+    const y = this._y
+    if (y !== null) {
+      transact(y, transaction => {
+        let { left, right, currentAttributes } = findPosition(transaction, y.store, this, index)
+        if (right === null) {
+          return
+        }
+        formatText(transaction, this, left, right, currentAttributes, length, attributes)
+      })
+    }
+  }
+
+  /**
+   * @param {encoding.Encoder} encoder
+   *
+   * @private
+   */
+  _write (encoder) {
+    encoding.writeVarUint(encoder, YTextRefID)
+  }
+}
+
+/**
+ * @param {decoding.Decoder} decoder
+ * @return {YText}
+ *
+ * @private
+ * @function
+ */
+export const readYText = decoder => new YText()

src/types/YXmlElement.js

@@ -0,0 +1,490 @@
+/**
+ * @module YXml
+ */
+
+import {
+  YXmlEvent,
+  AbstractType,
+  typeArrayMap,
+  typeArrayForEach,
+  typeMapGet,
+  typeMapGetAll,
+  typeArrayInsertGenerics,
+  typeArrayDelete,
+  typeMapSet,
+  typeMapDelete,
+  YXmlElementRefID,
+  callTypeObservers,
+  transact,
+  Y, Transaction, ItemType, YXmlText, YXmlHook, Snapshot // eslint-disable-line
+} from '../internals.js'
+
+import * as encoding from 'lib0/encoding.js'
+import * as decoding from 'lib0/decoding.js'
+
+/**
+ * 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 {IterableIterator}
+ */
+export class YXmlTreeWalker {
+  /**
+   * @param {YXmlFragment | YXmlElement} root
+   * @param {function(AbstractType<any>):boolean} [f]
+   */
+  constructor (root, f = () => true) {
+    this._filter = f
+    this._root = root
+    /**
+     * @type {ItemType | null}
+     */
+    // @ts-ignore
+    this._currentNode = root._start
+    this._firstCall = true
+  }
+
+  [Symbol.iterator] () {
+    return this
+  }
+  /**
+   * Get the next node.
+   *
+   * @return {IteratorResult<YXmlElement|YXmlText|YXmlHook>} The next node.
+   *
+   * @public
+   */
+  next () {
+    let n = this._currentNode
+    if (n !== null && (!this._firstCall || n.deleted || !this._filter(n.type))) { // if first call, we check if we can use the first item
+      do {
+        if (!n.deleted && (n.type.constructor === YXmlElement || n.type.constructor === YXmlFragment) && n.type._start !== null) {
+          // walk down in the tree
+          // @ts-ignore
+          n = n.type._start
+        } else {
+          // walk right or up in the tree
+          while (n !== null) {
+            if (n.right !== null) {
+              // @ts-ignore
+              n = n.right
+              break
+            } else if (n.parent === this._root) {
+              n = null
+            } else {
+              n = n.parent._item
+            }
+          }
+        }
+      } while (n !== null && (n.deleted || !this._filter(n.type)))
+    }
+    this._firstCall = false
+    this._currentNode = n
+    if (n === null) {
+      // @ts-ignore return undefined if done=true (the expected result)
+      return { value: undefined, done: true }
+    }
+    // @ts-ignore
+    return { value: n.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 {
+  /**
+   * 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 === 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 === query))
+  }
+
+  /**
+   * Creates YXmlEvent and calls observers.
+   * @private
+   *
+   * @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))
+  }
+
+  toString () {
+    return this.toDomString()
+  }
+
+  /**
+   * Get the string representation of all the children of this YXmlFragment.
+   *
+   * @return {string} The string representation of all children.
+   */
+  toDomString () {
+    return typeArrayMap(this, xml => xml.toDomString()).join('')
+  }
+
+  /**
+   * 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)
+    }
+    typeArrayForEach(this, xmlType => {
+      fragment.insertBefore(xmlType.toDom(_document, hooks, binding), null)
+    })
+    return fragment
+  }
+}
+
+/**
+ * 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.toUpperCase()
+    /**
+     * @type {Array<any>|null}
+     * @private
+     */
+    this._prelimContent = []
+    /**
+     * @type {Map<string, any>|null}
+     * @private
+     */
+    this._prelimAttrs = new Map()
+  }
+
+  /**
+   * 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 {Y} y The Yjs instance
+   * @param {ItemType} item
+   * @private
+   */
+  _integrate (y, item) {
+    super._integrate(y, item)
+    // @ts-ignore
+    this.insert(0, this._prelimContent)
+    this._prelimContent = null
+    // @ts-ignore
+    this._prelimAttrs.forEach((value, key) => {
+      this.setAttribute(key, value)
+    })
+    this._prelimContent = null
+  }
+
+  /**
+   * Creates an Item with the same effect as this Item (without position effect)
+   *
+   * @return {YXmlElement}
+   * @private
+   */
+  _copy () {
+    return new YXmlElement(this.nodeName)
+  }
+
+  toString () {
+    return this.toDomString()
+  }
+
+  /**
+   * Returns the string representation 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
+   */
+  toDomString () {
+    const attrs = this.getAttributes()
+    const stringBuilder = []
+    const keys = []
+    for (let 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}>${super.toDomString()}</${nodeName}>`
+  }
+
+  /**
+   * Removes an attribute from this YXmlElement.
+   *
+   * @param {String} attributeName The attribute name that is to be removed.
+   *
+   * @public
+   */
+  removeAttribute (attributeName) {
+    if (this._y !== null) {
+      transact(this._y, transaction => {
+        typeMapDelete(transaction, this, attributeName)
+      })
+    } else {
+      // @ts-ignore
+      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._y !== null) {
+      transact(this._y, transaction => {
+        typeMapSet(transaction, this, attributeName, attributeValue)
+      })
+    } else {
+      // @ts-ignore
+      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) {
+    // @ts-ignore
+    return typeMapGet(this, attributeName)
+  }
+
+  /**
+   * Returns all attribute name/value pairs in a JSON Object.
+   *
+   * @param {Snapshot} [snapshot]
+   * @return {Object} A JSON Object that describes the attributes.
+   *
+   * @public
+   */
+  getAttributes (snapshot) {
+    return typeMapGetAll(this)
+  }
+
+  /**
+   * 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._y !== null) {
+      transact(this._y, transaction => {
+        typeArrayInsertGenerics(transaction, this, index, content)
+      })
+    } else {
+      // @ts-ignore _prelimContent is defined because this is not yet integrated
+      this._prelimContent.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._y !== null) {
+      transact(this._y, transaction => {
+        typeArrayDelete(transaction, this, index, length)
+      })
+    } else {
+      // @ts-ignore _prelimContent is defined because this is not yet integrated
+      this._prelimContent.splice(index, length)
+    }
+  }
+
+  /**
+   * 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)
+    let attrs = this.getAttributes()
+    for (let key in attrs) {
+      dom.setAttribute(key, attrs[key])
+    }
+    typeArrayForEach(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.
+   *
+   * @private
+   * @param {encoding.Encoder} encoder The encoder to write data to.
+   */
+  _write (encoder) {
+    encoding.writeVarUint(encoder, YXmlElementRefID)
+    encoding.writeVarString(encoder, this.nodeName)
+  }
+}
+
+/**
+ * @param {decoding.Decoder} decoder
+ * @return {YXmlElement}
+ *
+ * @private
+ * @function
+ */
+export const readYXmlElement = decoder => new YXmlElement(decoding.readVarString(decoder))
+/**
+ * @param {decoding.Decoder} decoder
+ * @return {YXmlFragment}
+ *
+ * @private
+ * @function
+ */
+export const readYXmlFragment = decoder => new YXmlFragment()

src/types/YXmlEvent.js

@@ -0,0 +1,39 @@
+
+import {
+  YEvent,
+  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|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|null>}
+     */
+    this.attributesChanged = new Set()
+    subs.forEach((sub) => {
+      if (sub === null) {
+        this.childListChanged = true
+      } else {
+        this.attributesChanged.add(sub)
+      }
+    })
+  }
+}

src/types/YXmlHook.js

@@ -0,0 +1,90 @@
+
+import {
+  YMap,
+  YXmlHookRefID
+} from '../internals.js'
+import * as encoding from 'lib0/encoding.js'
+import * as decoding from 'lib0/decoding.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)
+   *
+   * @private
+   */
+  _copy () {
+    return new YXmlHook(this.hookName)
+  }
+
+  /**
+   * 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 {encoding.Encoder} encoder The encoder to write data to.
+   *
+   * @private
+   */
+  _write (encoder) {
+    super._write(encoder)
+    encoding.writeVarUint(encoder, YXmlHookRefID)
+    encoding.writeVarString(encoder, this.hookName)
+  }
+}
+
+/**
+ * @param {decoding.Decoder} decoder
+ * @return {YXmlHook}
+ *
+ * @private
+ * @function
+ */
+export const readYXmlHook = decoder =>
+  new YXmlHook(decoding.readVarString(decoder))

src/types/YXmlText.js

@@ -0,0 +1,51 @@
+
+import { YText, YXmlTextRefID } from '../internals.js'
+
+import * as encoding from 'lib0/encoding.js'
+import * as decoding from 'lib0/decoding.js' // eslint-disable-line
+
+/**
+ * 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 {
+  /**
+   * 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
+  }
+  /**
+   * @param {encoding.Encoder} encoder
+   *
+   * @private
+   */
+  _write (encoder) {
+    encoding.writeVarUint(encoder, YXmlTextRefID)
+  }
+}
+
+/**
+ * @param {decoding.Decoder} decoder
+ * @return {YXmlText}
+ *
+ * @private
+ * @function
+ */
+export const readYXmlText = decoder => new YXmlText()

src/utils/DeleteSet.js

@@ -0,0 +1,249 @@
+
+import {
+  findIndexSS,
+  createID,
+  getState,
+  AbstractItem, StructStore, Transaction, ID // eslint-disable-line
+} from '../internals.js'
+
+import * as math from 'lib0/math.js'
+import * as map from 'lib0/map.js'
+import * as encoding from 'lib0/encoding.js'
+import * as decoding from 'lib0/decoding.js'
+
+/**
+ * @private
+ */
+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.
+ *
+ * @private
+ */
+export class DeleteSet {
+  constructor () {
+    /**
+     * @type {Map<number,Array<DeleteItem>>}
+     * @private
+     */
+    this.clients = new Map()
+  }
+}
+
+/**
+ * @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 += right.len
+      } else {
+        if (j < i) {
+          dels[j] = right
+        }
+        j++
+      }
+    }
+    dels.length = j
+  })
+}
+
+/**
+ * @param {DeleteSet} ds
+ * @param {ID} id
+ * @param {number} length
+ *
+ * @private
+ * @function
+ */
+export const addToDeleteSet = (ds, id, length) => {
+  map.setIfUndefined(ds.clients, id.client, () => []).push(new DeleteItem(id.clock, length))
+}
+
+/**
+ * @param {StructStore} ss
+ * @return {DeleteSet} Merged and sorted DeleteSet
+ *
+ * @private
+ * @function
+ */
+export const createDeleteSetFromStructStore = ss => {
+  const ds = new DeleteSet()
+  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.id.clock === clock + len && 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 {encoding.Encoder} encoder
+ * @param {DeleteSet} ds
+ *
+ * @private
+ * @function
+ */
+export const writeDeleteSet = (encoder, ds) => {
+  encoding.writeVarUint(encoder, ds.clients.size)
+  ds.clients.forEach((dsitems, client) => {
+    encoding.writeVarUint(encoder, client)
+    const len = dsitems.length
+    encoding.writeVarUint(encoder, len)
+    for (let i = 0; i < len; i++) {
+      const item = dsitems[i]
+      encoding.writeVarUint(encoder, item.clock)
+      encoding.writeVarUint(encoder, item.len)
+    }
+  })
+}
+
+/**
+ * @param {decoding.Decoder} decoder
+ * @param {Transaction} transaction
+ * @param {StructStore} store
+ *
+ * @private
+ * @function
+ */
+export const readDeleteSet = (decoder, transaction, store) => {
+  const unappliedDS = new DeleteSet()
+  const numClients = decoding.readVarUint(decoder)
+  for (let i = 0; i < numClients; i++) {
+    const client = decoding.readVarUint(decoder)
+    const numberOfDeletes = decoding.readVarUint(decoder)
+    const structs = store.clients.get(client) || []
+    const state = getState(store, client)
+    for (let i = 0; i < numberOfDeletes; i++) {
+      const clock = decoding.readVarUint(decoder)
+      const len = decoding.readVarUint(decoder)
+      if (clock < state) {
+        if (state < clock + len) {
+          addToDeleteSet(unappliedDS, createID(client, state), clock + len - state)
+        }
+        let index = findIndexSS(structs, clock)
+        /**
+         * We can ignore the case of GC and Delete structs, because we are going to skip them
+         * @type {AbstractItem}
+         */
+        // @ts-ignore
+        let struct = structs[index]
+        // split the first item if necessary
+        if (!struct.deleted && struct.id.clock < clock) {
+          structs.splice(index + 1, 0, struct.splitAt(transaction, 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 < clock + len) {
+            if (!struct.deleted) {
+              if (clock + len < struct.id.clock + struct.length) {
+                structs.splice(index, 0, struct.splitAt(transaction, clock + len - struct.id.clock))
+              }
+              struct.delete(transaction)
+            }
+          } else {
+            break
+          }
+        }
+      } else {
+        addToDeleteSet(unappliedDS, createID(client, clock), len)
+      }
+    }
+  }
+  if (unappliedDS.clients.size > 0) {
+    const unappliedDSEncoder = encoding.createEncoder()
+    writeDeleteSet(unappliedDSEncoder, unappliedDS)
+    store.pendingDeleteReaders.push(decoding.createDecoder(encoding.toBuffer(unappliedDSEncoder)))
+  }
+}

src/utils/EventHandler.js

@@ -0,0 +1,82 @@
+import * as f from 'lib0/function.js'
+
+/**
+ * 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) => {
+  eventHandler.l = eventHandler.l.filter(g => f !== g)
+}
+
+/**
+ * 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 +1,100 @@
+
+import { AbstractType } from '../internals' // eslint-disable-line
+
+import * as decoding from 'lib0/decoding.js'
+import * as encoding from 'lib0/encoding.js'
+import * as error from 'lib0/error.js'
+
+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
+  }
+  /**
+   * @deprecated
+   * @todo remove and adapt relative position implementation
+   */
+  toJSON () {
+    return {
+      client: this.client,
+      clock: this.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 (let [key, value] of type._y.share) {
+    if (value === type) {
+      return key
+    }
+  }
+  throw error.unexpectedCase()
+}

src/utils/Snapshot.js

@@ -0,0 +1,44 @@
+
+import {
+  DeleteSet,
+  isDeleted,
+  AbstractItem // eslint-disable-line
+} from '../internals.js'
+
+export class Snapshot {
+  /**
+   * @param {DeleteSet} ds delete store
+   * @param {Map<number,number>} sm state map
+   * @param {Map<number,string>} userMap
+   * @private
+   */
+  constructor (ds, sm, userMap) {
+    /**
+     * @type {DeleteSet}
+     * @private
+     */
+    this.ds = new DeleteSet()
+    /**
+     * State Map
+     * @type {Map<number,number>}
+     * @private
+     */
+    this.sm = sm
+    /**
+     * @type {Map<number,string>}
+     * @private
+     */
+    this.userMap = userMap
+  }
+}
+
+/**
+ * @param {AbstractItem} item
+ * @param {Snapshot|undefined} snapshot
+ *
+ * @protected
+ * @function
+ */
+export const isVisible = (item, snapshot) => snapshot === undefined ? !item.deleted : (
+  snapshot.sm.has(item.id.client) && (snapshot.sm.get(item.id.client) || 0) > item.id.clock && !isDeleted(snapshot.ds, item.id)
+)

src/utils/StructStore.js

@@ -0,0 +1,303 @@
+
+import {
+  GC,
+  Transaction, AbstractStructRef, ID, ItemType, AbstractItem, AbstractStruct // eslint-disable-line
+} from '../internals.js'
+
+import * as math from 'lib0/math.js'
+import * as error from 'lib0/error.js'
+import * as encoding from 'lib0/encoding.js'
+import * as decoding from 'lib0/decoding.js'
+
+export class StructStore {
+  constructor () {
+    /**
+     * @type {Map<number,Array<AbstractStruct>>}
+     * @private
+     */
+    this.clients = new Map()
+    /**
+     * Store incompleted struct reads here
+     * `i` denotes to the next read operation
+     * We could shift the array of refs instead, but shift is incredible
+     * slow in Chrome for arrays with more than 100k elements
+     * @see tryResumePendingStructRefs
+     * @type {Map<number,{i:number,refs:Array<AbstractStructRef>}>}
+     * @private
+     */
+    this.pendingClientsStructRefs = new Map()
+    /**
+     * Stack of pending structs waiting for struct dependencies
+     * Maximum length of stack is structReaders.size
+     * @type {Array<AbstractStructRef>}
+     * @private
+     */
+    this.pendingStack = []
+    /**
+     * @type {Array<decoding.Decoder>}
+     * @private
+     */
+    this.pendingDeleteReaders = []
+  }
+}
+
+/**
+ * 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 getStates = 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 {AbstractStruct} 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<any>} structs
+ * @param {number} clock
+ * @return {number}
+ *
+ * @private
+ * @function
+ */
+export const findIndexSS = (structs, clock) => {
+  let left = 0
+  let right = structs.length - 1
+  while (left <= right) {
+    const midindex = math.floor((left + right) / 2)
+    const mid = structs[midindex]
+    const midclock = mid.id.clock
+    if (midclock <= clock) {
+      if (clock < midclock + mid.length) {
+        return midindex
+      }
+      left = midindex + 1
+    } else {
+      right = midindex - 1
+    }
+  }
+  // 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 {AbstractStruct}
+ *
+ * @private
+ * @function
+ */
+export const find = (store, id) => {
+  /**
+   * @type {Array<AbstractStruct>}
+   */
+  // @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.
+ *
+ * @param {StructStore} store
+ * @param {ID} id
+ * @return {AbstractItem}
+ *
+ * @private
+ * @function
+ */
+// @ts-ignore
+export const getItem = (store, id) => find(store, id)
+
+/**
+ * Expects that id is actually in store. This function throws or is an infinite loop otherwise.
+ *
+ * @param {StructStore} store
+ * @param {ID} id
+ * @return {ItemType}
+ *
+ * @private
+ * @function
+ */
+// @ts-ignore
+export const getItemType = (store, id) => find(store, id)
+
+/**
+ * Expects that id is actually in store. This function throws or is an infinite loop otherwise.
+ *
+ * @param {Transaction} transaction
+ * @param {StructStore} store
+ * @param {ID} id
+ * @return {AbstractItem}
+ *
+ * @private
+ * @function
+ */
+export const getItemCleanStart = (transaction, store, id) => {
+  /**
+   * @type {Array<AbstractItem>}
+   */
+  // @ts-ignore
+  const structs = store.clients.get(id.client)
+  const index = findIndexSS(structs, id.clock)
+  /**
+   * @type {AbstractItem}
+   */
+  let struct = structs[index]
+  if (struct.id.clock < id.clock && struct.constructor !== GC) {
+    struct = struct.splitAt(transaction, id.clock - struct.id.clock)
+    structs.splice(index + 1, 0, struct)
+  }
+  return struct
+}
+
+/**
+ * Expects that id is actually in store. This function throws or is an infinite loop otherwise.
+ *
+ * @param {Transaction} transaction
+ * @param {StructStore} store
+ * @param {ID} id
+ * @return {AbstractItem}
+ *
+ * @private
+ * @function
+ */
+export const getItemCleanEnd = (transaction, store, id) => {
+  /**
+   * @type {Array<AbstractItem>}
+   */
+  // @ts-ignore
+  const structs = 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, struct.splitAt(transaction, id.clock - struct.id.clock + 1))
+  }
+  return struct
+}
+
+/**
+ * Replace `item` with `newitem` in store
+ * @param {StructStore} store
+ * @param {AbstractStruct} struct
+ * @param {AbstractStruct} newStruct
+ *
+ * @private
+ * @function
+ */
+export const replaceStruct = (store, struct, newStruct) => {
+  /**
+   * @type {Array<AbstractStruct>}
+   */
+  // @ts-ignore
+  const structs = store.clients.get(struct.id.client)
+  structs[findIndexSS(structs, struct.id.clock)] = newStruct
+}
+
+/**
+ * Read StateMap from Decoder and return as Map
+ *
+ * @param {decoding.Decoder} decoder
+ * @return {Map<number,number>}
+ *
+ * @private
+ * @function
+ */
+export const readStatesAsMap = decoder => {
+  const ss = new Map()
+  const ssLength = decoding.readVarUint(decoder)
+  for (let i = 0; i < ssLength; i++) {
+    const client = decoding.readVarUint(decoder)
+    const clock = decoding.readVarUint(decoder)
+    ss.set(client, clock)
+  }
+  return ss
+}
+
+/**
+ * Write StateMap to Encoder
+ *
+ * @param {encoding.Encoder} encoder
+ * @param {StructStore} store
+ *
+ * @private
+ * @function
+ */
+export const writeStates = (encoder, store) => {
+  encoding.writeVarUint(encoder, store.clients.size)
+  store.clients.forEach((structs, client) => {
+    const id = structs[structs.length - 1].id
+    encoding.writeVarUint(encoder, id.client)
+    encoding.writeVarUint(encoder, id.clock)
+  })
+  return encoder
+}

src/utils/Transaction.js

@@ -0,0 +1,244 @@
+
+import {
+  getState,
+  createID,
+  writeStructsFromTransaction,
+  writeDeleteSet,
+  DeleteSet,
+  sortAndMergeDeleteSet,
+  getStates,
+  findIndexSS,
+  callEventHandlerListeners,
+  AbstractItem,
+  ItemDeleted,
+  ID, AbstractType, AbstractStruct, YEvent, Y // eslint-disable-line
+} from '../internals.js'
+
+import * as encoding from 'lib0/encoding.js'
+import * as map from 'lib0/map.js'
+import * as math from 'lib0/math.js'
+
+/**
+ * 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 {Y} y
+   */
+  constructor (y) {
+    /**
+     * The Yjs instance.
+     * @type {Y}
+     */
+    this.y = y
+    /**
+     * 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 = getStates(y.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 {encoding.Encoder|null}
+     * @private
+     */
+    this._updateMessage = null
+    /**
+     * @type {Set<ID>}
+     * @private
+     */
+    this._mergeStructs = new Set()
+  }
+  /**
+   * @type {encoding.Encoder|null}
+   * @public
+   */
+  get updateMessage () {
+    // only create if content was added in transaction (state or ds changed)
+    if (this._updateMessage === null && (this.deleteSet.clients.size > 0 || map.any(this.afterState, (clock, client) => this.beforeState.get(client) !== clock))) {
+      const encoder = encoding.createEncoder()
+      sortAndMergeDeleteSet(this.deleteSet)
+      writeStructsFromTransaction(encoder, this)
+      writeDeleteSet(encoder, this.deleteSet)
+      this._updateMessage = encoder
+    }
+    return this._updateMessage
+  }
+}
+
+/**
+ * @param {Transaction} transaction
+ *
+ * @private
+ * @function
+ */
+export const nextID = transaction => {
+  const y = transaction.y
+  return createID(y.clientID, getState(y.store, y.clientID))
+}
+
+/**
+ * Implements the functionality of `y.transact(()=>{..})`
+ *
+ * @param {Y} y
+ * @param {function(Transaction):void} f
+ *
+ * @private
+ * @function
+ */
+export const transact = (y, f) => {
+  let initialCall = false
+  if (y._transaction === null) {
+    initialCall = true
+    y._transaction = new Transaction(y)
+    y.emit('beforeTransaction', [y._transaction, y])
+  }
+  const transaction = y._transaction
+  try {
+    f(transaction)
+  } finally {
+    if (initialCall) {
+      y._transaction = null
+      y.emit('beforeObserverCalls', [transaction, y])
+      // emit change events on changed types
+      transaction.changed.forEach((subs, itemtype) => {
+        itemtype._callObserver(transaction, subs)
+      })
+      transaction.changedParentTypes.forEach((events, type) => {
+        events = events
+          .filter(event =>
+            event.target._item === null || !event.target._item.deleted
+          )
+        events
+          .forEach(event => {
+            event.currentTarget = type
+          })
+        // we don't need to check for events.length
+        // because we know it has at least one element
+        callEventHandlerListeners(type._dEH, events, transaction)
+      })
+      // only call afterTransaction listeners if anything changed
+      transaction.afterState = getStates(transaction.y.store)
+      // when all changes & events are processed, emit afterTransaction event
+      // transaction cleanup
+      const store = transaction.y.store
+      const ds = transaction.deleteSet
+      // replace deleted items with ItemDeleted / GC
+      sortAndMergeDeleteSet(ds)
+      y.emit('afterTransaction', [transaction, y])
+      for (const [client, deleteItems] of ds.clients) {
+        /**
+         * @type {Array<AbstractStruct>}
+         */
+        // @ts-ignore
+        const structs = store.clients.get(client)
+        for (let di = 0; di < deleteItems.length; di++) {
+          const deleteItem = deleteItems[di]
+          for (let si = findIndexSS(structs, deleteItem.clock); si < structs.length; si++) {
+            const struct = structs[si]
+            if (deleteItem.clock + deleteItem.len <= struct.id.clock) {
+              break
+            }
+            if (struct.deleted && struct instanceof AbstractItem && (struct.constructor !== ItemDeleted || (struct.parent._item !== null && struct.parent._item.deleted))) {
+              // check if we can GC
+              struct.gc(transaction, store)
+            }
+          }
+        }
+      }
+      /**
+       * @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 AbstractItem && right.parentSub !== null && right.parent._map.get(right.parentSub) === right) {
+              // @ts-ignore we already did a constructor check above
+              right.parent._map.set(right.parentSub, left)
+            }
+          }
+        }
+      }
+      // on all affected store.clients props, try to merge
+      for (const [client, clock] of transaction.afterState) {
+        const beforeClock = transaction.beforeState.get(client) || 0
+        if (beforeClock !== clock) {
+          /**
+           * @type {Array<AbstractStruct>}
+           */
+          // @ts-ignore
+          const structs = 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
+      for (const mid of transaction._mergeStructs) {
+        const client = mid.client
+        const clock = mid.clock
+        /**
+         * @type {Array<AbstractStruct>}
+         */
+        // @ts-ignore
+        const structs = store.clients.get(client)
+        const replacedStructPos = findIndexSS(structs, clock)
+        if (replacedStructPos + 1 < structs.length) {
+          tryToMergeWithLeft(structs, replacedStructPos + 1)
+        }
+        if (replacedStructPos > 0) {
+          tryToMergeWithLeft(structs, replacedStructPos)
+        }
+      }
+      y.emit('afterTransactionCleanup', [transaction, y])
+    }
+  }
+}

src/utils/UndoManager.js

@@ -0,0 +1,202 @@
+// @ts-nocheck
+
+import {
+  isParentOf,
+  createID,
+  transact
+} from '../internals.js'
+
+/**
+ * @private
+ */
+class ReverseOperation {
+  constructor (y, transaction, bindingInfos) {
+    this.created = new Date()
+    const beforeState = transaction.beforeState
+    if (beforeState.has(y.userID)) {
+      this.toState = createID(y.userID, y.ss.getState(y.userID) - 1)
+      this.fromState = createID(y.userID, beforeState.get(y.userID))
+    } else {
+      this.toState = null
+      this.fromState = null
+    }
+    this.deletedStructs = new Set()
+    transaction.deletedStructs.forEach(struct => {
+      this.deletedStructs.add({
+        from: struct._id,
+        len: struct._length
+      })
+    })
+    /**
+     * Maps from binding to binding information (e.g. cursor information)
+     */
+    this.bindingInfos = bindingInfos
+  }
+}
+
+/**
+ * @private
+ * @function
+ */
+function applyReverseOperation (y, scope, reverseBuffer) {
+  let performedUndo = false
+  let undoOp = null
+  transact(y, () => {
+    while (!performedUndo && reverseBuffer.length > 0) {
+      undoOp = reverseBuffer.pop()
+      // make sure that it is possible to iterate {from}-{to}
+      if (undoOp.fromState !== null) {
+        y.os.getItemCleanStart(undoOp.fromState)
+        y.os.getItemCleanEnd(undoOp.toState)
+        y.os.iterate(undoOp.fromState, undoOp.toState, op => {
+          while (op._deleted && op._redone !== null) {
+            op = op._redone
+          }
+          if (op._deleted === false && isParentOf(scope, op)) {
+            performedUndo = true
+            op._delete(y)
+          }
+        })
+      }
+      const redoitems = new Set()
+      for (let del of undoOp.deletedStructs) {
+        const fromState = del.from
+        const toState = createID(fromState.user, fromState.clock + del.len - 1)
+        y.os.getItemCleanStart(fromState)
+        y.os.getItemCleanEnd(toState)
+        y.os.iterate(fromState, toState, op => {
+          if (
+            isParentOf(scope, op) &&
+            op._parent !== y &&
+            (
+              op._id.user !== y.userID ||
+              undoOp.fromState === null ||
+              op._id.clock < undoOp.fromState.clock ||
+              op._id.clock > undoOp.toState.clock
+            )
+          ) {
+            redoitems.add(op)
+          }
+        })
+      }
+      redoitems.forEach(op => {
+        const opUndone = op._redo(y, redoitems)
+        performedUndo = performedUndo || opUndone
+      })
+    }
+  })
+  if (performedUndo && undoOp !== null) {
+    // should be performed after the undo transaction
+    undoOp.bindingInfos.forEach((info, binding) => {
+      binding._restoreUndoStackInfo(info)
+    })
+  }
+  return performedUndo
+}
+
+/**
+ * Saves a history of locally applied operations. The UndoManager handles the
+ * undoing and redoing of locally created changes.
+ *
+ * @private
+ * @function
+ */
+export class UndoManager {
+  /**
+   * @param {YType} scope The scope on which to listen for changes.
+   * @param {Object} options Optionally provided configuration.
+   */
+  constructor (scope, options = {}) {
+    this.options = options
+    this._bindings = new Set(options.bindings)
+    options.captureTimeout = options.captureTimeout == null ? 500 : options.captureTimeout
+    this._undoBuffer = []
+    this._redoBuffer = []
+    this._scope = scope
+    this._undoing = false
+    this._redoing = false
+    this._lastTransactionWasUndo = false
+    const y = scope._y
+    this.y = y
+    let bindingInfos
+    y.on('beforeTransaction', (y, transaction, remote) => {
+      if (!remote) {
+        // Store binding information before transaction is executed
+        // By restoring the binding information, we can make sure that the state
+        // before the transaction can be recovered
+        bindingInfos = new Map()
+        this._bindings.forEach(binding => {
+          bindingInfos.set(binding, binding._getUndoStackInfo())
+        })
+      }
+    })
+    y.on('afterTransaction', (y, transaction, remote) => {
+      if (!remote && transaction.changedParentTypes.has(scope)) {
+        let reverseOperation = new ReverseOperation(y, transaction, bindingInfos)
+        if (!this._undoing) {
+          let lastUndoOp = this._undoBuffer.length > 0 ? this._undoBuffer[this._undoBuffer.length - 1] : null
+          if (
+            this._redoing === false &&
+            this._lastTransactionWasUndo === false &&
+            lastUndoOp !== null &&
+            ((options.captureTimeout < 0) || (reverseOperation.created.getTime() - lastUndoOp.created.getTime()) <= options.captureTimeout)
+          ) {
+            lastUndoOp.created = reverseOperation.created
+            if (reverseOperation.toState !== null) {
+              lastUndoOp.toState = reverseOperation.toState
+              if (lastUndoOp.fromState === null) {
+                lastUndoOp.fromState = reverseOperation.fromState
+              }
+            }
+            reverseOperation.deletedStructs.forEach(lastUndoOp.deletedStructs.add, lastUndoOp.deletedStructs)
+          } else {
+            this._lastTransactionWasUndo = false
+            this._undoBuffer.push(reverseOperation)
+          }
+          if (!this._redoing) {
+            this._redoBuffer = []
+          }
+        } else {
+          this._lastTransactionWasUndo = true
+          this._redoBuffer.push(reverseOperation)
+        }
+      }
+    })
+  }
+
+  /**
+   * Enforce that the next change is created as a separate item in the undo stack
+   *
+   * @private
+   * @function
+   */
+  flushChanges () {
+    this._lastTransactionWasUndo = true
+  }
+
+  /**
+   * Undo the last locally created change.
+   *
+   * @private
+   * @function
+   */
+  undo () {
+    this._undoing = true
+    const performedUndo = applyReverseOperation(this.y, this._scope, this._undoBuffer)
+    this._undoing = false
+    return performedUndo
+  }
+
+  /**
+   * Redo the last locally created change.
+   *
+   * @private
+   * @function
+   */
+  redo () {
+    this._redoing = true
+    const performedRedo = applyReverseOperation(this.y, this._scope, this._redoBuffer)
+    this._redoing = false
+    return performedRedo
+  }
+}

src/utils/Y.js

@@ -0,0 +1,169 @@
+/**
+ * @module Y
+ */
+
+import {
+  StructStore,
+  AbstractType,
+  YArray,
+  YText,
+  YMap,
+  YXmlFragment,
+  transact,
+  Transaction, YEvent // eslint-disable-line
+} from '../internals.js'
+
+import { Observable } from 'lib0/observable.js'
+import * as random from 'lib0/random.js'
+import * as map from 'lib0/map.js'
+
+/**
+ * A Yjs instance handles the state of shared data.
+ * @extends Observable<string>
+ */
+export class Y extends Observable {
+  /**
+   * @param {Object|undefined} conf configuration
+   */
+  constructor (conf = {}) {
+    super()
+    // todo: change to clientId
+    this.clientID = random.uint32()
+    /**
+     * @type {Map<string, AbstractType<YEvent>>}
+     */
+    this.share = new Map()
+    this.store = new StructStore()
+    /**
+     * @type {Transaction | null}
+     * @private
+     */
+    this._transaction = null
+  }
+  /**
+   * 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
+   *
+   * @public
+   */
+  transact (f) {
+    transact(this, f)
+  }
+  /**
+   * 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
+   * @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) {
+        const t = new Constr()
+        t._map = type._map
+        t._start = type._start
+        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)
+  }
+  /**
+   * @param {string} name
+   * @return {YMap<any>}
+   *
+   * @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)
+  }
+  /**
+   * Emit `destroy` event and unregister all event handlers.
+   *
+   * @protected
+   */
+  destroy () {
+    this.emit('destroyed', [true])
+    super.destroy()
+  }
+  /**
+   * @param {string} eventName
+   * @param {function} f
+   */
+  on (eventName, f) {
+    super.on(eventName, f)
+  }
+  /**
+   * @param {string} eventName
+   * @param {function} f
+   */
+  off (eventName, f) {
+    super.off(eventName, f)
+  }
+}

src/utils/YEvent.js

@@ -0,0 +1,108 @@
+
+import {
+  isDeleted,
+  AbstractType, Transaction, AbstractStruct // eslint-disable-line
+} from '../internals.js'
+
+/**
+ * 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
+  }
+
+  /**
+   * Computes the path from `y` to the changed type.
+   *
+   * 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.
+   *
+   * @param {AbstractStruct} struct
+   * @return {boolean}
+   */
+  deletes (struct) {
+    return isDeleted(this.transaction.deleteSet, struct.id)
+  }
+
+  /**
+   * Check if a struct is added by this event.
+   *
+   * @param {AbstractStruct} struct
+   * @return {boolean}
+   */
+  adds (struct) {
+    return struct.id.clock >= (this.transaction.beforeState.get(struct.id.client) || 0)
+  }
+}
+
+/**
+ * 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 = child._item.parent._start
+      while (c !== child._item && c !== null) {
+        if (!c.deleted) {
+          i++
+        }
+        c = c.right
+      }
+      path.unshift(i)
+    }
+    child = child._item.parent
+  }
+  return path
+}

src/utils/cursor.js

@@ -0,0 +1,266 @@
+/**
+ * @module Cursors
+ */
+
+import {
+  getItem,
+  getItemType,
+  createID,
+  writeID,
+  readID,
+  compareIDs,
+  getState,
+  findRootTypeKey,
+  AbstractItem,
+  ID, StructStore, Y, AbstractType // eslint-disable-line
+} from '../internals.js'
+
+import * as encoding from 'lib0/encoding.js'
+import * as decoding from 'lib0/decoding.js'
+import * as error from 'lib0/error.js'
+
+/**
+ * A Cursor is a relative position that is based on the Yjs model. In contrast to an
+ * absolute position (position by index), the Cursor can be
+ * recomputed when remote changes are received. For example:
+ *
+ * ```Insert(0, 'x')('a|bc') = 'xa|bc'``` Where | is the cursor position.
+ *
+ * A relative cursor position can be obtained with the function
+ *
+ * One of the properties must be defined.
+ *
+ * @example
+ *   // Current cursor position is at position 10
+ *   const relativePosition = createCursorFromOffset(yText, 10)
+ *   // modify yText
+ *   yText.insert(0, 'abc')
+ *   yText.delete(3, 10)
+ *   // Compute the cursor position
+ *   const absolutePosition = toAbsolutePosition(y, relativePosition)
+ *   absolutePosition.type === yText // => true
+ *   console.log('cursor location is ' + absolutePosition.offset) // => cursor location is 3
+ *
+ */
+export class Cursor {
+  /**
+   * @param {ID|null} type
+   * @param {string|null} tname
+   * @param {ID|null} item
+   */
+  constructor (type, tname, item) {
+    /**
+     * @type {ID|null}
+     */
+    this.type = type
+    /**
+     * @type {string|null}
+     */
+    this.tname = tname
+    /**
+     * @type {ID | null}
+     */
+    this.item = item
+  }
+  toJSON () {
+    const json = {}
+    if (this.type !== null) {
+      json.type = this.type.toJSON()
+    }
+    if (this.tname !== null) {
+      json.tname = this.tname
+    }
+    if (this.item !== null) {
+      json.item = this.item.toJSON()
+    }
+    return json
+  }
+}
+
+/**
+ * @param {Object} json
+ * @return {Cursor}
+ *
+ * @function
+ */
+export const createCursorFromJSON = json => new Cursor(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))
+
+export class AbsolutePosition {
+  /**
+   * @param {AbstractType<any>} type
+   * @param {number} offset
+   */
+  constructor (type, offset) {
+    /**
+     * @type {AbstractType<any>}
+     */
+    this.type = type
+    /**
+     * @type {number}
+     */
+    this.offset = offset
+  }
+}
+
+/**
+ * @param {AbstractType<any>} type
+ * @param {number} offset
+ *
+ * @function
+ */
+export const createAbsolutePosition = (type, offset) => new AbsolutePosition(type, offset)
+
+/**
+ * @param {AbstractType<any>} type
+ * @param {ID|null} item
+ *
+ * @function
+ */
+export const createCursor = (type, item) => {
+  let typeid = null
+  let tname = null
+  if (type._item === null) {
+    tname = findRootTypeKey(type)
+  } else {
+    typeid = type._item.id
+  }
+  return new Cursor(typeid, tname, item)
+}
+
+/**
+ * Create a relativePosition based on a absolute position.
+ *
+ * @param {AbstractType<any>} type The base type (e.g. YText or YArray).
+ * @param {number} offset The absolute position.
+ * @return {Cursor}
+ *
+ * @function
+ */
+export const createCursorFromTypeOffset = (type, offset) => {
+  let t = type._start
+  while (t !== null) {
+    if (!t.deleted && t.countable) {
+      if (t.length > offset) {
+        // case 1: found position somewhere in the linked list
+        return createCursor(type, createID(t.id.client, t.id.clock + offset))
+      }
+      offset -= t.length
+    }
+    t = t.right
+  }
+  return createCursor(type, null)
+}
+
+/**
+ * @param {encoding.Encoder} encoder
+ * @param {Cursor} rpos
+ *
+ * @function
+ */
+export const writeCursor = (encoder, rpos) => {
+  const { type, tname, item } = 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()
+  }
+  return encoder
+}
+
+/**
+ * @param {decoding.Decoder} decoder
+ * @param {Y} y
+ * @param {StructStore} store
+ * @return {Cursor|null}
+ *
+ * @function
+ */
+export const readCursor = (decoder, y, store) => {
+  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)
+    }
+  }
+  return new Cursor(type, tname, itemID)
+}
+
+/**
+ * @param {Cursor} cursor
+ * @param {Y} y
+ * @return {AbsolutePosition|null}
+ *
+ * @function
+ */
+export const createAbsolutePositionFromCursor = (cursor, y) => {
+  const store = y.store
+  const rightID = cursor.item
+  const typeID = cursor.type
+  const tname = cursor.tname
+  let type = null
+  let offset = 0
+  if (rightID !== null) {
+    if (getState(store, rightID.client) <= rightID.clock) {
+      return null
+    }
+    const right = getItem(store, rightID)
+    if (!(right instanceof AbstractItem)) {
+      return null
+    }
+    offset = right.deleted || !right.countable ? 0 : rightID.clock - right.id.clock
+    let n = right.left
+    while (n !== null) {
+      if (!n.deleted && n.countable) {
+        offset += n.length
+      }
+      n = n.left
+    }
+    type = right.parent
+  } else {
+    if (tname !== null) {
+      type = y.get(tname)
+    } else if (typeID !== null) {
+      type = getItemType(store, typeID).type
+    } else {
+      throw error.unexpectedCase()
+    }
+    offset = type._length
+  }
+  if (type._item !== null && type._item.deleted) {
+    return null
+  }
+  return createAbsolutePosition(type, offset)
+}
+
+/**
+ * @param {Cursor|null} a
+ * @param {Cursor|null} b
+ *
+ * @function
+ */
+export const compareCursors = (a, b) => a === b || (
+  a !== null && b !== null && a.tname === b.tname && (
+    (a.item !== null && b.item !== null && compareIDs(a.item, b.item)) ||
+    (a.type !== null && b.type !== null && compareIDs(a.type, b.type))
+  )
+)

src/utils/encoding.js

@@ -0,0 +1,321 @@
+
+/**
+ * @module encoding
+ */
+
+import {
+  findIndexSS,
+  GCRef,
+  ItemBinaryRef,
+  ItemDeletedRef,
+  ItemEmbedRef,
+  ItemFormatRef,
+  ItemJSONRef,
+  ItemStringRef,
+  ItemTypeRef,
+  writeID,
+  createID,
+  readID,
+  getState,
+  getStates,
+  readDeleteSet,
+  writeDeleteSet,
+  createDeleteSetFromStructStore,
+  Transaction, AbstractStruct, AbstractStructRef, StructStore, ID // eslint-disable-line
+} from '../internals.js'
+
+import * as encoding from 'lib0/encoding.js'
+import * as decoding from 'lib0/decoding.js'
+import * as binary from 'lib0/binary.js'
+
+/**
+ * @private
+ */
+export const structRefs = [
+  GCRef,
+  ItemBinaryRef,
+  ItemDeletedRef,
+  ItemEmbedRef,
+  ItemFormatRef,
+  ItemJSONRef,
+  ItemStringRef,
+  ItemTypeRef
+]
+
+/**
+ * @param {encoding.Encoder} encoder
+ * @param {Array<AbstractStruct>} 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
+  const startNewStructs = findIndexSS(structs, clock)
+  // write # encoded structs
+  encoding.writeVarUint(encoder, structs.length - startNewStructs)
+  writeID(encoder, createID(client, clock))
+  const firstStruct = structs[startNewStructs]
+  // write first struct with an offset
+  firstStruct.write(encoder, clock - firstStruct.id.clock, 0)
+  for (let i = startNewStructs + 1; i < structs.length; i++) {
+    structs[i].write(encoder, 0, 0)
+  }
+}
+
+/**
+ * @param {decoding.Decoder} decoder
+ * @param {number} numOfStructs
+ * @param {ID} nextID
+ * @return {Array<AbstractStructRef>}
+ *
+ * @private
+ * @function
+ */
+const readStructRefs = (decoder, numOfStructs, nextID) => {
+  /**
+   * @type {Array<AbstractStructRef>}
+   */
+  const refs = []
+  for (let i = 0; i < numOfStructs; i++) {
+    const info = decoding.readUint8(decoder)
+    const ref = new structRefs[binary.BITS5 & info](decoder, nextID, info)
+    nextID = createID(nextID.client, nextID.clock + ref.length)
+    refs.push(ref)
+  }
+  return refs
+}
+
+/**
+ * @param {encoding.Encoder} 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)
+    }
+  })
+  getStates(store).forEach((clock, client) => {
+    if (!_sm.has(client)) {
+      sm.set(client, 0)
+    }
+  })
+  // write # states that were updated
+  encoding.writeVarUint(encoder, sm.size)
+  sm.forEach((clock, client) => {
+    // @ts-ignore
+    writeStructs(encoder, store.clients.get(client), client, clock)
+  })
+}
+
+/**
+ * @param {decoding.Decoder} decoder The decoder object to read data from.
+ * @return {Map<number,Array<AbstractStructRef>>}
+ *
+ * @private
+ * @function
+ */
+export const readClientsStructRefs = decoder => {
+  /**
+   * @type {Map<number,Array<AbstractStructRef>>}
+   */
+  const clientRefs = new Map()
+  const numOfStateUpdates = decoding.readVarUint(decoder)
+  for (let i = 0; i < numOfStateUpdates; i++) {
+    const numberOfStructs = decoding.readVarUint(decoder)
+    const nextID = readID(decoder)
+    const refs = readStructRefs(decoder, numberOfStructs, nextID)
+    clientRefs.set(nextID.client, refs)
+  }
+  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
+ *
+ * @private
+ * @function
+ */
+const resumeStructIntegration = (transaction, store) => {
+  const stack = store.pendingStack
+  const clientsStructRefs = store.pendingClientsStructRefs
+  // iterate over all struct readers until we are done
+  while (stack.length !== 0 || clientsStructRefs.size !== 0) {
+    if (stack.length === 0) {
+      // take any first struct from clientsStructRefs and put it on the stack
+      const [client, structRefs] = clientsStructRefs.entries().next().value
+      stack.push(structRefs.refs[structRefs.i++])
+      if (structRefs.refs.length === structRefs.i) {
+        clientsStructRefs.delete(client)
+      }
+    }
+    const ref = stack[stack.length - 1]
+    const m = ref._missing
+    const client = ref.id.client
+    const localClock = getState(store, client)
+    const offset = ref.id.clock < localClock ? localClock - ref.id.clock : 0
+    if (ref.id.clock + offset !== localClock) {
+      // A previous message from this client is missing
+      // check if there is a pending structRef with a smaller clock and switch them
+      const structRefs = clientsStructRefs.get(client)
+      if (structRefs !== undefined) {
+        const r = structRefs.refs[structRefs.i]
+        if (r.id.clock < ref.id.clock) {
+          // put ref with smaller clock on stack instead and continue
+          structRefs.refs[structRefs.i] = ref
+          stack[stack.length - 1] = r
+          // sort the set because this approach might bring the list out of order
+          structRefs.refs = structRefs.refs.slice(structRefs.i).sort((r1, r2) => r1.id.client - r2.id.client)
+          structRefs.i = 0
+          continue
+        }
+      }
+      // wait until missing struct is available
+      return
+    }
+    while (m.length > 0) {
+      const missing = m[m.length - 1]
+      if (getState(store, missing.client) <= missing.clock) {
+        const client = missing.client
+        // get the struct reader that has the missing struct
+        const structRefs = clientsStructRefs.get(client)
+        if (structRefs === undefined) {
+          // This update message causally depends on another update message.
+          return
+        }
+        stack.push(structRefs.refs[structRefs.i++])
+        if (structRefs.i === structRefs.refs.length) {
+          clientsStructRefs.delete(client)
+        }
+        break
+      }
+      ref._missing.pop()
+    }
+    if (m.length === 0) {
+      if (offset < ref.length) {
+        ref.toStruct(transaction, store, offset).integrate(transaction)
+      }
+      stack.pop()
+    }
+  }
+}
+
+/**
+ * @param {Transaction} transaction
+ * @param {StructStore} store
+ *
+ * @private
+ * @function
+ */
+export const tryResumePendingDeleteReaders = (transaction, store) => {
+  const pendingReaders = store.pendingDeleteReaders
+  store.pendingDeleteReaders = []
+  for (let i = 0; i < pendingReaders.length; i++) {
+    readDeleteSet(pendingReaders[i], transaction, store)
+  }
+}
+
+/**
+ * @param {encoding.Encoder} encoder
+ * @param {Transaction} transaction
+ *
+ * @private
+ * @function
+ */
+export const writeStructsFromTransaction = (encoder, transaction) => writeClientsStructs(encoder, transaction.y.store, transaction.beforeState)
+
+/**
+ * @param {StructStore} store
+ * @param {Map<number, Array<AbstractStructRef>>} clientsStructsRefs
+ *
+ * @private
+ * @function
+ */
+const mergeReadStructsIntoPendingReads = (store, clientsStructsRefs) => {
+  const pendingClientsStructRefs = store.pendingClientsStructRefs
+  for (const [client, structRefs] of clientsStructsRefs) {
+    const pendingStructRefs = pendingClientsStructRefs.get(client)
+    if (pendingStructRefs === undefined) {
+      pendingClientsStructRefs.set(client, { refs: structRefs, i: 0 })
+    } else {
+      // merge into existing structRefs
+      const merged = pendingStructRefs.i > 0 ? pendingStructRefs.refs.slice(pendingStructRefs.i) : pendingStructRefs.refs
+      for (let i = 0; i < structRefs.length; i++) {
+        merged.push(structRefs[i])
+      }
+      pendingStructRefs.i = 0
+      pendingStructRefs.refs = merged.sort((r1, r2) => r1.id.clock - r2.id.clock)
+    }
+  }
+}
+
+/**
+ * Read the next Item in a Decoder and fill this Item with the read data.
+ *
+ * This is called when data is received from a remote peer.
+ *
+ * @param {decoding.Decoder} decoder The decoder object to read data from.
+ * @param {Transaction} transaction
+ * @param {StructStore} store
+ *
+ * @private
+ * @function
+ */
+export const readStructs = (decoder, transaction, store) => {
+  const clientsStructRefs = readClientsStructRefs(decoder)
+  mergeReadStructsIntoPendingReads(store, clientsStructRefs)
+  resumeStructIntegration(transaction, store)
+  tryResumePendingDeleteReaders(transaction, store)
+}
+
+/**
+ * @param {decoding.Decoder} decoder
+ * @param {Transaction} transaction
+ * @param {StructStore} store
+ *
+ * @function
+ */
+export const readModel = (decoder, transaction, store) => {
+  readStructs(decoder, transaction, store)
+  readDeleteSet(decoder, transaction, store)
+}
+
+/**
+ * @param {encoding.Encoder} encoder
+ * @param {StructStore} store
+ * @param {Map<number,number>} [targetState] The state of the target that receives the update. Leave empty to write all known structs
+ *
+ * @function
+ */
+export const writeModel = (encoder, store, targetState = new Map()) => {
+  writeClientsStructs(encoder, store, targetState)
+  writeDeleteSet(encoder, createDeleteSetFromStructStore(store))
+}

src/utils/isParentOf.js

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

src/y.js

@@ -1,237 +0,0 @@
-/* @flow */
-'use strict'
-
-require('./Connector.js')(Y)
-require('./Database.js')(Y)
-require('./Transaction.js')(Y)
-require('./Struct.js')(Y)
-require('./Utils.js')(Y)
-require('./Connectors/Test.js')(Y)
-
-Y.debug = require('debug')
-
-var requiringModules = {}
-
-module.exports = Y
-Y.requiringModules = requiringModules
-
-Y.extend = function (name, value) {
-  if (arguments.length === 2 && typeof name === 'string') {
-    if (value instanceof Y.utils.CustomTypeDefinition) {
-      Y[name] = value.parseArguments
-    } else {
-      Y[name] = value
-    }
-    if (requiringModules[name] != null) {
-      requiringModules[name].resolve()
-      delete requiringModules[name]
-    }
-  } else {
-    for (var i = 0; i < arguments.length; i++) {
-      var f = arguments[i]
-      if (typeof f === 'function') {
-        f(Y)
-      } else {
-        throw new Error('Expected function!')
-      }
-    }
-  }
-}
-
-Y.requestModules = requestModules
-function requestModules (modules) {
-  var sourceDir
-  if (Y.sourceDir === null) {
-    sourceDir = null
-  } else {
-    sourceDir = Y.sourceDir || '/bower_components'
-  }
-  // determine if this module was compiled for es5 or es6 (y.js vs. y.es6)
-  // if Insert.execute is a Function, then it isnt a generator..
-  // then load the es5(.js) files..
-  var extention = typeof regeneratorRuntime !== 'undefined' ? '.js' : '.es6'
-  var promises = []
-  for (var i = 0; i < modules.length; i++) {
-    var module = modules[i].split('(')[0]
-    var modulename = 'y-' + module.toLowerCase()
-    if (Y[module] == null) {
-      if (requiringModules[module] == null) {
-        // module does not exist
-        if (typeof window !== 'undefined' && window.Y !== 'undefined') {
-          if (sourceDir != null) {
-            var imported = document.createElement('script')
-            imported.src = sourceDir + '/' + modulename + '/' + modulename + extention
-            document.head.appendChild(imported)
-          }
-          let requireModule = {}
-          requiringModules[module] = requireModule
-          requireModule.promise = new Promise(function (resolve) {
-            requireModule.resolve = resolve
-          })
-          promises.push(requireModule.promise)
-        } else {
-          console.info('YJS: Please do not depend on automatic requiring of modules anymore! Extend modules as follows `require(\'y-modulename\')(Y)`')
-          require(modulename)(Y)
-        }
-      } else {
-        promises.push(requiringModules[modules[i]].promise)
-      }
-    }
-  }
-  return Promise.all(promises)
-}
-
-/* ::
-type MemoryOptions = {
-  name: 'memory'
-}
-type IndexedDBOptions = {
-  name: 'indexeddb',
-  namespace: string
-}
-type DbOptions = MemoryOptions | IndexedDBOptions
-
-type WebRTCOptions = {
-  name: 'webrtc',
-  room: string
-}
-type WebsocketsClientOptions = {
-  name: 'websockets-client',
-  room: string
-}
-type ConnectionOptions = WebRTCOptions | WebsocketsClientOptions
-
-type YOptions = {
-  connector: ConnectionOptions,
-  db: DbOptions,
-  types: Array<TypeName>,
-  sourceDir: string,
-  share: {[key: string]: TypeName}
-}
-*/
-
-function Y (opts/* :YOptions */) /* :Promise<YConfig> */ {
-  if (opts.hasOwnProperty('sourceDir')) {
-    Y.sourceDir = opts.sourceDir
-  }
-  opts.types = opts.types != null ? opts.types : []
-  var modules = [opts.db.name, opts.connector.name].concat(opts.types)
-  for (var name in opts.share) {
-    modules.push(opts.share[name])
-  }
-  return new Promise(function (resolve, reject) {
-    if (opts == null) reject('An options object is expected! ')
-    else if (opts.connector == null) reject('You must specify a connector! (missing connector property)')
-    else if (opts.connector.name == null) reject('You must specify connector name! (missing connector.name property)')
-    else if (opts.db == null) reject('You must specify a database! (missing db property)')
-    else if (opts.connector.name == null) reject('You must specify db name! (missing db.name property)')
-    else {
-      opts = Y.utils.copyObject(opts)
-      opts.connector = Y.utils.copyObject(opts.connector)
-      opts.db = Y.utils.copyObject(opts.db)
-      opts.share = Y.utils.copyObject(opts.share)
-      setTimeout(function () {
-        Y.requestModules(modules).then(function () {
-          var yconfig = new YConfig(opts)
-          yconfig.db.whenUserIdSet(function () {
-            yconfig.init(function () {
-              resolve(yconfig)
-            })
-          })
-        }).catch(reject)
-      }, 0)
-    }
-  })
-}
-
-class YConfig {
-  /* ::
-  db: Y.AbstractDatabase;
-  connector: Y.AbstractConnector;
-  share: {[key: string]: any};
-  options: Object;
-  */
-  constructor (opts, callback) {
-    this.options = opts
-    this.db = new Y[opts.db.name](this, opts.db)
-    this.connector = new Y[opts.connector.name](this, opts.connector)
-    this.connected = true
-  }
-  init (callback) {
-    var opts = this.options
-    var share = {}
-    this.share = share
-    this.db.requestTransaction(function * requestTransaction () {
-      // create shared object
-      for (var propertyname in opts.share) {
-        var typeConstructor = opts.share[propertyname].split('(')
-        var typeName = typeConstructor.splice(0, 1)
-        var type = Y[typeName]
-        var typedef = type.typeDefinition
-        var id = ['_', typedef.struct + '_' + typeName + '_' + propertyname + '_' + typeConstructor]
-        var args = []
-        if (typeConstructor.length === 1) {
-          try {
-            args = JSON.parse('[' + typeConstructor[0].split(')')[0] + ']')
-          } catch (e) {
-            throw new Error('Was not able to parse type definition! (share.' + propertyname + ')')
-          }
-          if (type.typeDefinition.parseArguments == null) {
-            throw new Error(typeName + ' does not expect arguments!')
-          } else {
-            args = typedef.parseArguments(args[0])[1]
-          }
-        }
-        share[propertyname] = yield* this.store.initType.call(this, id, args)
-      }
-      this.store.whenTransactionsFinished()
-        .then(callback)
-    })
-  }
-  isConnected () {
-    return this.connector.isSynced
-  }
-  disconnect () {
-    if (this.connected) {
-      this.connected = false
-      return this.connector.disconnect()
-    } else {
-      return Promise.resolve()
-    }
-  }
-  reconnect () {
-    if (!this.connected) {
-      this.connected = true
-      return this.connector.reconnect()
-    } else {
-      return Promise.resolve()
-    }
-  }
-  destroy () {
-    var self = this
-    return this.close().then(function () {
-      if (self.db.deleteDB != null) {
-        return self.db.deleteDB()
-      } else {
-        return Promise.resolve()
-      }
-    })
-  }
-  close () {
-    var self = this
-    this.share = null
-    if (this.connector.destroy != null) {
-      this.connector.destroy()
-    } else {
-      this.connector.disconnect()
-    }
-    return this.db.whenTransactionsFinished(function () {
-      this.db.destroyTypes()
-      // make sure to wait for all transactions before destroying the db
-      this.db.requestTransaction(function * () {
-        yield* self.db.destroy()
-      })
-      return this.db.whenTransactionsFinished()
-    })
-  }
-}

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>

tests/encoding.tests.js

@@ -0,0 +1,36 @@
+import * as t from 'lib0/testing.js'
+
+import {
+  structRefs,
+  structGCRefNumber,
+  structBinaryRefNumber,
+  structDeletedRefNumber,
+  structEmbedRefNumber,
+  structFormatRefNumber,
+  structJSONRefNumber,
+  structStringRefNumber,
+  structTypeRefNumber,
+  GCRef,
+  ItemBinaryRef,
+  ItemDeletedRef,
+  ItemEmbedRef,
+  ItemFormatRef,
+  ItemJSONRef,
+  ItemStringRef,
+  ItemTypeRef
+} from '../src/internals.js'
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testStructReferences = tc => {
+  t.assert(structRefs.length === 8)
+  t.assert(structRefs[structGCRefNumber] === GCRef)
+  t.assert(structRefs[structBinaryRefNumber] === ItemBinaryRef)
+  t.assert(structRefs[structDeletedRefNumber] === ItemDeletedRef)
+  t.assert(structRefs[structEmbedRefNumber] === ItemEmbedRef)
+  t.assert(structRefs[structFormatRefNumber] === ItemFormatRef)
+  t.assert(structRefs[structJSONRefNumber] === ItemJSONRef)
+  t.assert(structRefs[structStringRefNumber] === ItemStringRef)
+  t.assert(structRefs[structTypeRefNumber] === ItemTypeRef)
+}

tests/index.js

@@ -0,0 +1,22 @@
+
+import * as array from './y-array.tests.js'
+import * as map from './y-map.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 { runTests } from 'lib0/testing.js'
+import { isBrowser, isNode } from 'lib0/environment.js'
+import * as log from 'lib0/logging.js'
+
+if (isBrowser) {
+  log.createVConsole(document.body)
+}
+runTests({
+  map, array, text, xml, encoding
+}).then(success => {
+  /* istanbul ignore next */
+  if (isNode) {
+    process.exit(success ? 0 : 1)
+  }
+})

tests/testHelper.js

@@ -0,0 +1,397 @@
+import * as Y from '../src/index.js'
+
+import {
+  createDeleteSetFromStructStore,
+  getStates,
+  AbstractItem,
+  DeleteSet, StructStore // eslint-disable-line
+} from '../src/internals.js'
+
+import * as t from 'lib0/testing.js'
+import * as prng from 'lib0/prng.js'
+import { createMutex } from 'lib0/mutex.js'
+import * as encoding from 'lib0/encoding.js'
+import * as decoding from 'lib0/decoding.js'
+import * as syncProtocol from 'y-protocols/sync.js'
+
+/**
+ * @param {TestYInstance} y
+ * @param {Y.Transaction} transaction
+ */
+const afterTransaction = (y, transaction) => {
+  y.mMux(() => {
+    const m = transaction.updateMessage
+    if (m !== null) {
+      const encoder = encoding.createEncoder()
+      syncProtocol.writeUpdate(encoder, m)
+      broadcastMessage(y, encoding.toBuffer(encoder))
+    }
+  })
+}
+
+/**
+ * @param {TestYInstance} y // publish message created by `y` to all other online clients
+ * @param {ArrayBuffer} m
+ */
+const broadcastMessage = (y, m) => {
+  if (y.tc.onlineConns.has(y)) {
+    y.tc.onlineConns.forEach(remoteYInstance => {
+      if (remoteYInstance !== y) {
+        remoteYInstance._receive(m, y)
+      }
+    })
+  }
+}
+
+export class TestYInstance extends Y.Y {
+  /**
+   * @param {TestConnector} testConnector
+   * @param {number} clientID
+   */
+  constructor (testConnector, clientID) {
+    super()
+    this.userID = clientID // overwriting clientID
+    /**
+     * @type {TestConnector}
+     */
+    this.tc = testConnector
+    /**
+     * @type {Map<TestYInstance, Array<ArrayBuffer>>}
+     */
+    this.receiving = new Map()
+    /**
+     * Message mutex
+     * @type {Function}
+     */
+    this.mMux = createMutex()
+    testConnector.allConns.add(this)
+    // set up observe on local model
+    this.on('afterTransactionCleanup', afterTransaction)
+    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.store)
+      // publish SyncStep1
+      broadcastMessage(this, encoding.toBuffer(encoder))
+      this.tc.onlineConns.forEach(remoteYInstance => {
+        if (remoteYInstance !== this) {
+          // remote instance sends instance to this instance
+          const encoder = encoding.createEncoder()
+          syncProtocol.writeSyncStep1(encoder, remoteYInstance.store)
+          this._receive(encoding.toBuffer(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 {ArrayBuffer} 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()
+      receiver.mMux(() => {
+        // 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)
+      })
+      if (encoding.length(encoder) > 0) {
+        // send reply message
+        sender._receive(encoding.toBuffer(encoder), receiver)
+      }
+      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
+  }
+}
+
+/**
+ * @param {t.TestCase} tc
+ * @param {{users?:number}} conf
+ * @return {{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 } = {}) => {
+  /**
+   * @type {Object<string,any>}
+   */
+  const result = {
+    users: []
+  }
+  const gen = tc.prng
+  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.get('array', Y.Array)
+    result['map' + i] = y.get('map', Y.Map)
+    result['xml' + i] = y.get('xml', Y.XmlElement)
+    result['text' + i] = y.get('text', Y.Text)
+  }
+  testConnector.syncAll()
+  // @ts-ignore
+  return 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()) {}
+  const userArrayValues = users.map(u => u.getArray('array').toJSON().map(val => JSON.stringify(val)))
+  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.pendingDeleteReaders.length === 0)
+    t.assert(u.store.pendingStack.length === 0)
+    t.assert(u.store.pendingClientsStructRefs.size === 0)
+  }
+  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])
+    // @ts-ignore
+    t.compare(userTextValues[i].map(a => a.insert).join('').length, users[i].getText('text').length)
+    t.compare(userTextValues[i], userTextValues[i + 1])
+    t.compare(getStates(users[i].store), getStates(users[i + 1].store))
+    compareDS(createDeleteSetFromStructStore(users[i].store), createDeleteSetFromStructStore(users[i + 1].store))
+    compareStructStores(users[i].store, users[i + 1].store)
+  }
+  users.map(u => u.destroy())
+}
+
+/**
+ * @param {AbstractItem?} a
+ * @param {AbstractItem?} b
+ * @return {boolean}
+ */
+export const compareItemIDs = (a, b) => a === b || (a !== null && b != null && Y.compareIDs(a.id, b.id))
+
+/**
+ * @param {StructStore} ss1
+ * @param {StructStore} ss2
+ */
+export const compareStructStores = (ss1, ss2) => {
+  t.assert(ss1.clients.size === ss2.clients.size)
+  for (const [client, structs1] of ss1.clients) {
+    const structs2 = ss2.clients.get(client)
+    t.assert(structs2 !== undefined && structs1.length === structs2.length)
+    for (let i = 0; i < structs1.length; i++) {
+      const s1 = structs1[i]
+      // @ts-ignore
+      const s2 = structs2[i]
+      // checks for abstract struct
+      if (
+        s1.constructor !== s2.constructor ||
+        !Y.compareIDs(s1.id, s2.id) ||
+        s1.deleted !== s2.deleted ||
+        s1.length !== s2.length
+      ) {
+        t.fail('Structs dont match')
+      }
+      if (s1 instanceof AbstractItem) {
+        if (
+          !(s2 instanceof AbstractItem) ||
+          !((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 {DeleteSet} ds1
+ * @param {DeleteSet} ds2
+ */
+export const compareDS = (ds1, ds2) => {
+  t.assert(ds1.clients.size === ds2.clients.size)
+  for (const [client, deleteItems1] of ds1.clients) {
+    const deleteItems2 = ds2.clients.get(client)
+    t.assert(deleteItems2 !== undefined && deleteItems1.length === deleteItems2.length)
+    for (let i = 0; i < deleteItems1.length; i++) {
+      const di1 = deleteItems1[i]
+      // @ts-ignore
+      const di2 = deleteItems2[i]
+      if (di1.clock !== di2.clock || di1.len !== di2.len) {
+        t.fail('DeleteSets dont match')
+      }
+    }
+  }
+}
+
+/**
+ * @param {t.TestCase} tc
+ * @param {Array<function(TestYInstance,prng.PRNG):void>} mods
+ * @param {number} iterations
+ */
+export const applyRandomTests = (tc, mods, iterations) => {
+  const gen = tc.prng
+  const result = init(tc, { users: 5 })
+  const { testConnector, users } = result
+  for (var i = 0; i < iterations; i++) {
+    if (prng.int31(gen, 0, 100) <= 2) {
+      // 2% chance to disconnect/reconnect a random user
+      if (prng.bool(gen)) {
+        testConnector.disconnectRandom()
+      } else {
+        testConnector.reconnectRandom()
+      }
+    } else if (prng.int31(gen, 0, 100) <= 1) {
+      // 1% chance to flush all
+      testConnector.flushAllMessages()
+    } else if (prng.int31(gen, 0, 100) <= 50) {
+      // 50% chance to flush a random message
+      testConnector.flushRandomMessage()
+    }
+    let user = prng.oneOf(gen, users)
+    var test = prng.oneOf(gen, mods)
+    test(user, gen)
+  }
+  compare(users)
+  return result
+}

tests/y-array.tests.js

@@ -0,0 +1,422 @@
+import { init, compare, applyRandomTests, TestYInstance } from './testHelper.js' // eslint-disable-line
+
+import * as Y from '../src/index.js'
+import * as t from 'lib0/testing.js'
+import * as prng from 'lib0/prng.js'
+
+/**
+ * @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, 2, 3])
+  t.compare(array0.toJSON(), [1, 2, 3], '.toJSON() works')
+  testConnector.flushAllMessages()
+  t.compare(array1.toJSON(), [1, 2, 3], '.toJSON() works after sync')
+  compare(users)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testConcurrentInsertWithThreeConflicts = tc => {
+  var { 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 => {
+  var { 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 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)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testInsertAndDeleteEventsForTypes2 = tc => {
+  const { array0, users } = init(tc, { users: 2 })
+  /**
+   * @type {Array<Object<string,any>>}
+   */
+  let 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)
+}
+
+/**
+ * @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 testIteratingArrayContainingTypes = tc => {
+  const y = new Y.Y()
+  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 (let item of arr) {
+    t.assert(item.get('value') === cnt++, 'value is correct')
+  }
+  y.destroy()
+}
+
+let _uniqueNumber = 0
+const getUniqueNumber = () => _uniqueNumber++
+
+/**
+ * @type {Array<function(TestYInstance,prng.PRNG):void>}
+ */
+const arrayTransactions = [
+  function insert (user, gen) {
+    const yarray = user.getArray('array')
+    var uniqueNumber = getUniqueNumber()
+    var content = []
+    var len = prng.int31(gen, 1, 4)
+    for (var i = 0; i < len; i++) {
+      content.push(uniqueNumber)
+    }
+    var pos = prng.int31(gen, 0, yarray.length)
+    yarray.insert(pos, content)
+  },
+  function insertTypeArray (user, gen) {
+    const yarray = user.getArray('array')
+    var pos = prng.int31(gen, 0, yarray.length)
+    yarray.insert(pos, [new Y.Array()])
+    var array2 = yarray.get(pos)
+    array2.insert(0, [1, 2, 3, 4])
+  },
+  function insertTypeMap (user, gen) {
+    const yarray = user.getArray('array')
+    var pos = prng.int31(gen, 0, yarray.length)
+    yarray.insert(pos, [new Y.Map()])
+    var map = yarray.get(pos)
+    map.set('someprop', 42)
+    map.set('someprop', 43)
+    map.set('someprop', 44)
+  },
+  function _delete (user, gen) {
+    const yarray = user.getArray('array')
+    var length = yarray.length
+    if (length > 0) {
+      var somePos = prng.int31(gen, 0, length - 1)
+      var delLength = prng.int31(gen, 1, Math.min(2, length - somePos))
+      if (prng.bool(gen)) {
+        var type = yarray.get(somePos)
+        if (type.length > 0) {
+          somePos = prng.int31(gen, 0, type.length - 1)
+          delLength = prng.int31(gen, 0, Math.min(2, type.length - somePos))
+          type.delete(somePos, delLength)
+        }
+      } else {
+        yarray.delete(somePos, delLength)
+      }
+    }
+  }
+]
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYarrayTests20 = tc => {
+  applyRandomTests(tc, arrayTransactions, 3)
+}
+
+/**
+ * @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 +1,460 @@
+import { init, compare, applyRandomTests, TestYInstance } 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.js'
+import * as prng from 'lib0/prng.js'
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testBasicMapTests = tc => {
+  const { testConnector, users, map0, map1, map2 } = init(tc, { users: 3 })
+  users[2].disconnect()
+
+  map0.set('number', 1)
+  map0.set('string', 'hello Y')
+  map0.set('object', { key: { key2: 'value' } })
+  map0.set('y-map', new Y.Map())
+  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('number') === 1, 'client 0 computed the change (number)')
+  t.assert(map0.get('string') === 'hello Y', 'client 0 computed the change (string)')
+  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)')
+
+  users[2].connect()
+  testConnector.flushAllMessages()
+
+  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.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)')
+
+  // compare disconnected user
+  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.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 (let 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 (let user of users) {
+    var 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 (let user of users) {
+    var u = user.getMap('map')
+    t.compare(u.get('stuff'), 'c1')
+  }
+  compare(users)
+}
+
+/**
+ * @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 (let user of users) {
+    var u = user.getMap('map')
+    t.assert(u.get('stuff') === undefined)
+  }
+  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 (let user of users) {
+    var 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 (let user of users) {
+    var 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 (var 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 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(TestYInstance,prng.PRNG):void>}
+ */
+const mapTransactions = [
+  function set (user, gen) {
+    let key = prng.oneOf(gen, ['one', 'two'])
+    var value = prng.utf16String(gen)
+    user.getMap('map').set(key, value)
+  },
+  function setType (user, gen) {
+    let key = prng.oneOf(gen, ['one', 'two'])
+    var 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) {
+    let key = prng.oneOf(gen, ['one', 'two'])
+    user.getMap('map').delete(key)
+  }
+]
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testRepeatGeneratingYmapTests10 = tc => {
+  applyRandomTests(tc, mapTransactions, 10)
+}
+
+/**
+ * @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 +1,69 @@
+import { init, compare } from './testHelper.js'
+
+import * as t from 'lib0/testing.js'
+
+/**
+ * @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 }])
+  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.string === '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)
+}

tests/y-xml.tests.js

@@ -0,0 +1,75 @@
+import { init, compare } from './testHelper.js'
+import * as Y from '../src/index.js'
+
+import * as t from 'lib0/testing.js'
+
+/**
+ * @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 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 })
+  let paragraph1 = new Y.XmlElement('p')
+  let paragraph2 = new Y.XmlElement('p')
+  let text1 = new Y.XmlText('init')
+  let text2 = new Y.XmlText('text')
+  paragraph1.insert(0, [text1, text2])
+  xml0.insert(0, [paragraph1, paragraph2, new Y.XmlElement('img')])
+  let 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)
+}

tsconfig.json

@@ -0,0 +1,62 @@
+{
+  "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": "./",                       /* Concatenate and emit output to single file. */
+    // "outDir": "./build",                        /* 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. */
+    // "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": {},                           /* 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": 5,
+    // "types": ["./src/utils/typedefs.js"]
+  },
+  "include": ["./src/**/*", "./tests/**/*"],
+  "exclude": ["../lib0/**/*", "node_modules"]
+}