13.6.11

fix Y.Text formatting issue - closes #606
add linear as a user of Yjs
2024-01-21 11:30:14 +01:00 · 2024-01-21 11:27:12 +01:00 · 2024-01-15 14:11:28 +01:00 · 2024-01-10 17:27:03 +01:00 · 2023-12-28 15:31:00 +01:00 · 2023-12-23 11:16:57 +01:00
57 changed files with 3799 additions and 3952 deletions
--- a/.github/workflows/node.js.yml
+++ b/.github/workflows/node.js.yml
@@ -16,14 +16,16 @@ jobs:

    strategy:
      matrix:
-        node-version: [10.x, 12.x, 14.x]
+        node-version: [16.x, 20.x]

    steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
    - name: Use Node.js ${{ matrix.node-version }}
-      uses: actions/setup-node@v1
+      uses: actions/setup-node@v3
      with:
        node-version: ${{ matrix.node-version }}
    - run: npm ci
-    - run: npm run build --if-present
-    - run: npm test
+    - run: npm run lint
+    - run: npm run test
+      env:
+        CI: true
--- a/.github/workflows/nodejs.yml
+++ b/.github/workflows/nodejs.yml
@@ -1,31 +0,0 @@
-# This workflow will do a clean install of node dependencies, build the source code and run tests across different versions of node
-# For more information see: https://help.github.com/actions/language-and-framework-guides/using-nodejs-with-github-actions
-
-name: Node.js CI
-
-on:
-  push:
-    branches: [ master ]
-  pull_request:
-    branches: [ master ]
-
-jobs:
-  build:
-
-    runs-on: ubuntu-latest
-
-    strategy:
-      matrix:
-        node-version: [10.x, 12.x, 13.x]
-
-    steps:
-    - uses: actions/checkout@v2
-    - name: Use Node.js ${{ matrix.node-version }}
-      uses: actions/setup-node@v1
-      with:
-        node-version: ${{ matrix.node-version }}
-    - run: npm ci
-    - run: npm run lint
-    - run: npm run test-extensive
-      env:
-        CI: true
--- a/INTERNALS.md
+++ b/INTERNALS.md
@@ -66,7 +66,7 @@ fields, respectively. These are used when peers concurrently insert at the same
 location in a document. Though quite rare in practice, Yjs needs to make sure
 the list items always resolve to the same order on all peers. The actual logic
 is relatively simple - its only a couple dozen lines of code and it lives in
-the `Item#integrate()` method. The YATA paper has much more detail on the this
+the `Item#integrate()` method. The YATA paper has much more detail on this
 algorithm.

 ### Item Storage
@@ -149,8 +149,8 @@ concepts that can be used to create a custom network protocol:

 * `update`: The Yjs document can be encoded to an *update* object that can be
  parsed to reconstruct the document. Also every change on the document fires
-an incremental document updates that allows clients to sync with each other.
-The update object is an Uint8Array that efficiently encodes `Item` objects and
+an incremental document update that allows clients to sync with each other.
+The update object is a Uint8Array that efficiently encodes `Item` objects and
 the delete set.
 * `state vector`: A state vector defines the known state of each user (a set of
  tuples `(client, clock)`). This object is also efficiently encoded as a
--- a/4
+++ b/4
@@ -1,7 +1,7 @@
 The MIT License (MIT)

-Copyright (c) 2014
-  - Kevin Jahns <kevin.jahns@rwth-aachen.de>.
+Copyright (c) 2023
+  - Kevin Jahns <kevin.jahns@protonmail.com>.
  - Chair of Computer Science 5 (Databases & Information Systems), RWTH Aachen University, Germany

 Permission is hereby granted, free of charge, to any person obtaining a copy
--- a/README.md
+++ b/README.md
@@ -15,6 +15,7 @@ suited for even large documents.

 * Demos: [https://github.com/yjs/yjs-demos](https://github.com/yjs/yjs-demos)
 * Discuss: [https://discuss.yjs.dev](https://discuss.yjs.dev)
+* Chat: [Gitter](https://gitter.im/Yjs/community) | [Discord](https://discord.gg/T3nqMT6qbM)
 * Benchmark Yjs vs. Automerge:
  [https://github.com/dmonad/crdt-benchmarks](https://github.com/dmonad/crdt-benchmarks)
 * Podcast [**"Yjs Deep Dive into real time collaborative editing solutions":**](https://www.tag1consulting.com/blog/deep-dive-real-time-collaborative-editing-solutions-tagteamtalk-001-0)
@@ -31,9 +32,30 @@ Otherwise you can find help on our community [discussion board](https://discuss.
 Please contribute to the project financially - especially if your company relies
 on Yjs. [![Become a Sponsor](https://img.shields.io/static/v1?label=Become%20a%20Sponsor&message=%E2%9D%A4&logo=GitHub&style=flat&color=d42f2d)](https://github.com/sponsors/dmonad)

+## Professional Support
+
+* [Support Contract with the Maintainer](https://github.com/sponsors/dmonad) -
+By contributing financially to the open-source Yjs project, you can receive
+professional support directly from the author. This includes the opportunity for
+weekly video calls to discuss your specific challenges.
+* [Synergy Codes](https://synergycodes.com/yjs-services/) - Specializing in
+consulting and developing real-time collaborative editing solutions for visual
+apps, Synergy Codes focuses on interactive diagrams, complex graphs, charts, and
+various data visualization types. Their expertise empowers developers to build
+engaging and interactive visual experiences leveraging the power of Yjs. See
+their work in action at [Visual Collaboration
+Showcase](https://yjs-diagram.synergy.codes/).
+
 ## Who is using Yjs

-* [Dynaboard](https://dynaboard.com/) Build web apps collaboratively. :star2:
+* [AFFiNE](https://affine.pro/) A local-first, privacy-first, open source
+  knowledge base. 🏅
+* [Cargo](https://cargo.site/) Site builder for designers and artists :star2:
+* [Gitbook](https://gitbook.com) Knowledge management for technical teams :star2:
+* [Evernote](https://evernote.com) Note-taking app :star2:
+* [Lessonspace](https://thelessonspace.com) Enterprise platform for virtual
+  classrooms and online training :star2:
+* [Dynaboard](https://dynaboard.com/) Build web apps collaboratively. :star:
 * [Relm](https://www.relm.us/) A collaborative gameworld for teamwork and
  community. :star:
 * [Room.sh](https://room.sh/) A meeting application with integrated
@@ -42,6 +64,8 @@ on Yjs. [![Become a Sponsor](https://img.shields.io/static/v1?label=Become%20a%2
  Nimbus Web. :star:
 * [Pluxbox RadioManager](https://getradiomanager.com/) A web-based app to
  collaboratively organize radio broadcasts. :star:
+* [Sana](https://sanalabs.com/) A learning platform with collaborative text
+  editing powered by Yjs.
 * [Serenity Notes](https://www.serenity.re/en/notes) End-to-end encrypted
  collaborative notes app.
 * [PRSM](https://prsm.uk/) Collaborative mind-mapping and system visualisation. *[(source)](https://github.com/micrology/prsm)*
@@ -51,12 +75,29 @@ on Yjs. [![Become a Sponsor](https://img.shields.io/static/v1?label=Become%20a%2
 * [Slidebeamer](https://slidebeamer.com/) Presentation app.
 * [BlockSurvey](https://blocksurvey.io) End-to-end encryption for your forms/surveys.
 * [Skiff](https://skiff.org/) Private, decentralized workspace.
+* [JupyterLab](https://jupyter.org/) Collaborative computational Notebooks
+* [JupyterCad](https://jupytercad.readthedocs.io/en/latest/) Extension to
+  JupyterLab that enables collaborative editing of 3d FreeCAD Models.
+* [Hyperquery](https://hyperquery.ai/) A collaborative data workspace for
+  sharing analyses, documentation, spreadsheets, and dashboards.
+* [Nosgestesclimat](https://nosgestesclimat.fr/groupe) The french carbon
+  footprint calculator has a group P2P mode based on yjs
+* [oorja.io](https://oorja.io) Online meeting spaces extensible with
+  collaborative apps, end-to-end encrypted.
+* [LegendKeeper](https://legendkeeper.com) Collaborative campaign planner and
+  worldbuilding app for tabletop RPGs.
+* [IllumiDesk](https://illumidesk.com/) Build courses and content with A.I.
+* [btw](https://www.btw.so) Open-source Medium alternative
+* [AWS SageMaker](https://aws.amazon.com/sagemaker/) Tools for building Machine
+  Learning Models
+* [linear](https://linear.app) Streamline issues, projects, and product roadmaps.

 ## Table of Contents

 * [Overview](#Overview)
  * [Bindings](#Bindings)
  * [Providers](#Providers)
+  * [Ports](#Ports)
 * [Getting Started](#Getting-Started)
 * [API](#API)
  * [Shared Types](#Shared-Types)
@@ -82,9 +123,11 @@ are implemented in separate modules.
 | [CodeMirror](https://codemirror.net/) | ✔ | [y-codemirror](https://github.com/yjs/y-codemirror) | [demo](https://demos.yjs.dev/codemirror/codemirror.html) |
 | [Monaco](https://microsoft.github.io/monaco-editor/) | ✔ | [y-monaco](https://github.com/yjs/y-monaco) | [demo](https://demos.yjs.dev/monaco/monaco.html) |
 | [Slate](https://github.com/ianstormtaylor/slate) | ✔ | [slate-yjs](https://github.com/bitphinix/slate-yjs) | [demo](https://bitphinix.github.io/slate-yjs-example) |
+| [BlockSuite](https://github.com/toeverything/blocksuite) | ✔ | (native) | [demo](https://blocksuite-toeverything.vercel.app/?init) |
 | [valtio](https://github.com/pmndrs/valtio) |  | [valtio-yjs](https://github.com/dai-shi/valtio-yjs) | [demo](https://codesandbox.io/s/valtio-yjs-demo-ox3iy) |
 | [immer](https://github.com/immerjs/immer) |  | [immer-yjs](https://github.com/sep2/immer-yjs) | [demo](https://codesandbox.io/s/immer-yjs-demo-6e0znb) |
 | React / Vue / Svelte / MobX | | [SyncedStore](https://syncedstore.org) | [demo](https://syncedstore.org/docs/react) |
+| [mobx-keystone](https://mobx-keystone.js.org/) |  | [mobx-keystone-yjs](https://github.com/xaviergonz/mobx-keystone/tree/master/packages/mobx-keystone-yjs) | [demo](https://mobx-keystone.js.org/examples/yjs-binding) |

 ### Providers

@@ -93,7 +136,19 @@ and storing shared data for offline usage is quite a hassle. **Providers**
 manage all that for you and are the perfect starting point for your
 collaborative app.

+> This list of providers is incomplete. Please open PRs to add your providers to
+> this list!
+
+#### Connection Providers
+
 <dl>
+  <dt><a href="https://github.com/yjs/y-websocket">y-websocket</a></dt>
+  <dd>
+A module that contains a simple websocket backend and a websocket client that
+connects to that backend. The backend can be extended to persist updates in a
+leveldb database. <b>y-sweet</b> and <b>ypy-websocket</b> (see below) are
+compatible to the y-wesocket protocol.
+  </dd>
  <dt><a href="https://github.com/yjs/y-webrtc">y-webrtc</a></dt>
  <dd>
 Propagates document updates peer-to-peer using WebRTC. The peers exchange
@@ -102,17 +157,22 @@ are available. Communication over the signaling servers can be encrypted by
 providing a shared secret, keeping the connection information and the shared
 document private.
  </dd>
-  <dt><a href="https://github.com/yjs/y-websocket">y-websocket</a></dt>
+  <dt><a href="https://github.com/liveblocks/liveblocks">@liveblocks/yjs</a></dt>
  <dd>
-A module that contains a simple websocket backend and a websocket client that
-connects to that backend. The backend can be extended to persist updates in a
-leveldb database.
+<a href="https://liveblocks.io/document/yjs">Liveblocks Yjs</a> provides a fully
+hosted WebSocket infrastructure and persisted data store for Yjs
+documents. No configuration or maintenance is required. It also features
+Yjs webhook events, REST API to read and update Yjs documents, and a
+browser DevTools extension.
  </dd>
-  <dt><a href="https://github.com/yjs/y-indexeddb">y-indexeddb</a></dt>
+  <dt><a href="https://github.com/drifting-in-space/y-sweet">y-sweet</a></dt>
  <dd>
-Efficiently persists document updates to the browsers indexeddb database.
-The document is immediately available and only diffs need to be synced through the
-network provider.
+A standalone yjs server with persistence to S3 or filesystem. They offer a
+<a href="https://y-sweet.cloud">cloud service</a> as well.
+  </dd>
+  <dt><a href="https://docs.partykit.io/reference/y-partykit-api/">PartyKit</a></dt>
+  <dd>
+Cloud service for building multiplayer apps.
  </dd>
  <dt><a href="https://github.com/marcopolo/y-libp2p">y-libp2p</a></dt>
  <dd>
@@ -135,9 +195,55 @@ Use Matrix as transport and storage of Yjs updates, so you can focus building
 your client app and Matrix can provide powerful features like Authentication,
 Authorization, Federation, hosting (self-hosting or SaaS) and even End-to-End
 Encryption (E2EE).
-</dd>
+  </dd>
+  <dt><a href="https://github.com/y-crdt/yrb-actioncable">yrb-actioncable</a></dt>
+  <dd>
+An ActionCable companion for Yjs clients. There is a fitting
+<a href="https://github.com/y-crdt/yrb-redis">redis extension</a> as well.
+  </dd>
+  <dt><a href="https://github.com/y-crdt/ypy-websocket">ypy-websocket</a></dt>
+  <dd>
+Websocket backend, written in Python.
+  </dd>
 </dl>

+#### Persistence Providers
+
+<dl>
+  <dt><a href="https://github.com/yjs/y-indexeddb">y-indexeddb</a></dt>
+  <dd>
+Efficiently persists document updates to the browsers indexeddb database.
+The document is immediately available and only diffs need to be synced through the
+network provider.
+  </dd>
+  <dt><a href="https://github.com/MaxNoetzold/y-mongodb-provider">y-mongodb-provider</a></dt>
+  <dd>
+Adds persistent storage to a server with MongoDB. Can be used with the
+y-websocket provider.
+  </dd>
+  <dt><a href="https://github.com/toeverything/AFFiNE/tree/master/packages/y-indexeddb">
+@toeverything/y-indexeddb</a></dt>
+  <dd>
+Like y-indexeddb, but with sub-documents support and fully TypeScript.
+  </dd>
+</dl>
+
+# Ports
+
+There are several Yjs-compatible ports to other programming languages.
+
+* [y-octo](https://github.com/toeverything/y-octo) - Rust implementation by
+[AFFiNE](https://affine.pro)
+* [y-crdt](https://github.com/y-crdt/y-crdt) - Rust implementation with multiple
+language bindings to other languages
+  * [yrs](https://github.com/y-crdt/y-crdt/tree/main/yrs) - Rust interface
+  * [ypy](https://github.com/y-crdt/ypy) - Python binding
+  * [yrb](https://github.com/y-crdt/yrb) - Ruby binding
+  * [yswift](https://github.com/y-crdt/yswift) - Swift binding
+  * [yffi](https://github.com/y-crdt/y-crdt/tree/main/yffi) - C-FFI
+  * [ywasm](https://github.com/y-crdt/y-crdt/tree/main/ywasm) - WASM binding
+* [ycs](https://github.com/yjs/ycs) - .Net compatible C# implementation.
+
 ## Getting Started

 Install Yjs and a provider with your favorite package manager:
@@ -155,6 +261,9 @@ PORT=1234 node ./node_modules/y-websocket/bin/server.js
 ### Example: Observe types

 ```js
+import * as Y from 'yjs';
+
+const doc = new Y.Doc();
 const yarray = doc.getArray('my-array')
 yarray.observe(event => {
  console.log('yarray was modified')
@@ -628,6 +737,8 @@ type. Doesn't log types that have not been defined (using
  <dd>Define a shared Y.Array type. Is equivalent to <code>y.get(string, Y.Array)</code>.</dd>
  <b><code>getMap(string):Y.Map</code></b>
  <dd>Define a shared Y.Map type. Is equivalent to <code>y.get(string, Y.Map)</code>.</dd>
+  <b><code>getText(string):Y.Text</code></b>
+  <dd>Define a shared Y.Text type. Is equivalent to <code>y.get(string, Y.Text)</code>.</dd>
  <b><code>getXmlFragment(string):Y.XmlFragment</code></b>
  <dd>Define a shared Y.XmlFragment type. Is equivalent to <code>y.get(string, Y.XmlFragment)</code>.</dd>
  <b><code>on(string, function)</code></b>
@@ -642,7 +753,8 @@ type. Doesn't log types that have not been defined (using
  <b><code>on('update', function(updateMessage:Uint8Array, origin:any, Y.Doc):void)</code></b>
  <dd>
 Listen to document updates. Document updates must be transmitted to all other
-peers. You can apply document updates in any order and multiple times.
+peers. You can apply document updates in any order and multiple times. Use `updateV2`
+to receive V2 events.
  </dd>
  <b><code>on('beforeTransaction', function(Y.Transaction, Y.Doc):void)</code></b>
  <dd>Emitted before each transaction.</dd>
@@ -734,7 +846,31 @@ const diff2 = Y.diffUpdate(currentState2, stateVector1)

 // sync clients
 currentState1 = Y.mergeUpdates([currentState1, diff2])
-currentState1 = Y.mergeUpdates([currentState1, diff1])
+currentState2 = Y.mergeUpdates([currentState2, diff1])
+```
+
+#### Obfuscating Updates
+
+If one of your users runs into a weird bug (e.g. the rich-text editor throws
+error messages), then you don't have to request the full document from your
+user. Instead, they can obfuscate the document (i.e. replace the content with
+meaningless generated content) before sending it to you. Note that someone might
+still deduce the type of content by looking at the general structure of the
+document. But this is much better than requesting the original document.
+
+Obfuscated updates contain all the CRDT-related data that is required for
+merging. So it is safe to merge obfuscated updates.
+
+```javascript
+const ydoc = new Y.Doc()
+// perform some changes..
+ydoc.getText().insert(0, 'hello world')
+const update = Y.encodeStateAsUpdate(ydoc)
+// the below update contains scrambled data
+const obfuscatedUpdate = Y.obfuscateUpdate(update)
+const ydoc2 = new Y.Doc()
+Y.applyUpdate(ydoc2, obfuscatedUpdate)
+ydoc2.getText().toString() // => "00000000000"
 ```

 #### Using V2 update format
@@ -743,8 +879,10 @@ Yjs implements two update formats. By default you are using the V1 update format
 You can opt-in into the V2 update format wich provides much better compression.
 It is not yet used by all providers. However, you can already use it if
 you are building your own provider. All below functions are available with the
-suffix "V2". E.g. `Y.applyUpdate` ⇒ `Y.applyUpdateV2`. We also support conversion
-functions between both formats: `Y.convertUpdateFormatV1ToV2` & `Y.convertUpdateFormatV2ToV1`.
+suffix "V2". E.g. `Y.applyUpdate` ⇒ `Y.applyUpdateV2`. Also when listening to updates
+you need to specifically need listen for V2 events e.g. `yDoc.on('updateV2', …)`.
+We also support conversion functions between both formats:
+`Y.convertUpdateFormatV1ToV2` & `Y.convertUpdateFormatV2ToV1`.

 #### Update API

@@ -989,7 +1127,7 @@ doc.transact(() => {
  ytext.insert(0, 'abc')
 }, 41)
 undoManager.undo()
-ytext.toString() // => '' (not tracked because 41 is not an instance of
+ytext.toString() // => 'abc' (not tracked because 41 is not an instance of
                 //        `trackedTransactionorigins`)
 ytext.delete(0, 3) // revert change

@@ -1047,16 +1185,17 @@ More information about the specific implementation is available in
 [INTERNALS.md](./INTERNALS.md) and in
 [this walkthrough of the Yjs codebase](https://youtu.be/0l5XgnQ6rB4).

-CRDTs that suitable for shared text editing suffer from the fact that they only grow
-in size. There are CRDTs that do not grow in size, but they do not have the
-characteristics that are benificial for shared text editing (like intention
-preservation). Yjs implements many improvements to the original algorithm that
-diminish the trade-off that the document only grows in size. We can't garbage
-collect deleted structs (tombstones) while ensuring a unique order of the
-structs. But we can 1. merge preceeding structs into a single struct to reduce
-the amount of meta information, 2. we can delete content from the struct if it
-is deleted, and 3. we can garbage collect tombstones if we don't care about the
-order of the structs anymore (e.g. if the parent was deleted).
+CRDTs that are suitable for shared text editing suffer from the fact that they
+only grow in size. There are CRDTs that do not grow in size, but they do not
+have the characteristics that are benificial for shared text editing (like
+intention preservation). Yjs implements many improvements to the original
+algorithm that diminish the trade-off that the document only grows in size. We
+can't garbage collect deleted structs (tombstones) while ensuring a unique
+order of the structs. But we can 1. merge preceeding structs into a single
+struct to reduce the amount of meta information, 2. we can delete content from
+the struct if it is deleted, and 3. we can garbage collect tombstones if we
+don't care about the order of the structs anymore (e.g. if the parent was
+deleted).

 **Examples:**

--- a/package-lock.json
+++ b/package-lock.json
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
  "name": "yjs",
-  "version": "13.5.36",
+  "version": "13.6.11",
  "description": "Shared Editing Library",
  "main": "./dist/yjs.cjs",
  "module": "./dist/yjs.mjs",
@@ -26,6 +26,8 @@
  },
  "exports": {
    ".": {
+      "types": "./dist/src/index.d.ts",
+      "module": "./dist/yjs.mjs",
      "import": "./dist/yjs.mjs",
      "require": "./dist/yjs.cjs"
    },
@@ -73,19 +75,24 @@
  },
  "homepage": "https://docs.yjs.dev",
  "dependencies": {
-    "lib0": "^0.2.49"
+    "lib0": "^0.2.86"
  },
  "devDependencies": {
-    "@rollup/plugin-commonjs": "^17.0.0",
-    "@rollup/plugin-node-resolve": "^11.2.1",
+    "@rollup/plugin-commonjs": "^24.0.1",
+    "@rollup/plugin-node-resolve": "^15.0.1",
+    "@types/node": "^18.15.5",
    "concurrently": "^3.6.1",
    "http-server": "^0.12.3",
    "jsdoc": "^3.6.7",
    "markdownlint-cli": "^0.23.2",
-    "rollup": "^2.60.0",
+    "rollup": "^3.20.0",
    "standard": "^16.0.4",
    "tui-jsdoc-template": "^1.2.2",
-    "typescript": "^4.4.4",
+    "typescript": "^4.9.5",
    "y-protocols": "^1.0.5"
+  },
+  "engines": {
+    "npm": ">=8.0.0",
+    "node": ">=16.0.0"
  }
 }
--- a/rollup.config.js
+++ b/rollup.config.js
@@ -42,13 +42,7 @@ export default [{
    name: 'Y',
    file: 'dist/yjs.cjs',
    format: 'cjs',
-    sourcemap: true,
-    paths: path => {
-      if (/^lib0\//.test(path)) {
-        return `lib0/dist/${path.slice(5)}.cjs`
-      }
-      return path
-    }
+    sourcemap: true
  },
  external: id => /^lib0\//.test(id)
 }, {
@@ -88,7 +82,7 @@ export default [{
  plugins: [
    debugResolve,
    nodeResolve({
-      mainFields: ['module', 'browser', 'main']
+      mainFields: ['browser', 'module', 'main']
    }),
    commonjs()
  ]
@@ -103,9 +97,10 @@ export default [{
  plugins: [
    debugResolve,
    nodeResolve({
-      mainFields: ['module', 'main']
+      mainFields: ['node', 'module', 'main'],
+      exportConditions: ['node', 'module', 'import', 'default']
    }),
    commonjs()
  ],
-  external: ['isomorphic.js']
+  external: id => /^lib0\//.test(id)
 }]
--- a/src/index.js
+++ b/src/index.js
@@ -18,8 +18,10 @@ export {
  Item,
  AbstractStruct,
  GC,
+  Skip,
  ContentBinary,
  ContentDeleted,
+  ContentDoc,
  ContentEmbed,
  ContentFormat,
  ContentJSON,
@@ -50,6 +52,7 @@ export {
  getItem,
  typeListToArraySnapshot,
  typeMapGetSnapshot,
+  typeMapGetAllSnapshot,
  createDocFromSnapshot,
  iterateDeletedStructs,
  applyUpdate,
@@ -89,21 +92,31 @@ export {
  diffUpdate,
  diffUpdateV2,
  convertUpdateFormatV1ToV2,
-  convertUpdateFormatV2ToV1
+  convertUpdateFormatV2ToV1,
+  obfuscateUpdate,
+  obfuscateUpdateV2,
+  UpdateEncoderV1,
+  UpdateEncoderV2,
+  UpdateDecoderV1,
+  UpdateDecoderV2,
+  equalDeleteSets,
+  snapshotContainsUpdate
 } from './internals.js'

-const glo = /** @type {any} */ (typeof window !== 'undefined'
-  ? window
-  // @ts-ignore
-  : typeof global !== 'undefined' ? global : {})
+const glo = /** @type {any} */ (typeof globalThis !== 'undefined'
+  ? globalThis
+  : typeof window !== 'undefined'
+    ? window
+    // @ts-ignore
+    : typeof global !== 'undefined' ? global : {})

 const importIdentifier = '__ $YJS$ __'

 if (glo[importIdentifier] === true) {
  /**
-   * Dear reader of this warning message. Please take this seriously.
+   * Dear reader of this message. Please take this seriously.
   *
-   * If you see this message, please make sure that you only import one version of Yjs. In many cases,
+   * If you see this message, make sure that you only import one version of Yjs. In many cases,
   * your package manager installs two versions of Yjs that are used by different packages within your project.
   * Another reason for this message is that some parts of your project use the commonjs version of Yjs
   * and others use the EcmaScript version of Yjs.
@@ -111,7 +124,9 @@ if (glo[importIdentifier] === true) {
   * This often leads to issues that are hard to debug. We often need to perform constructor checks,
   * e.g. `struct instanceof GC`. If you imported different versions of Yjs, it is impossible for us to
   * do the constructor checks anymore - which might break the CRDT algorithm.
+   *
+   * https://github.com/yjs/yjs/issues/438
   */
-  console.warn('Yjs was already imported. Importing different versions of Yjs often leads to issues.')
+  console.error('Yjs was already imported. This breaks constructor checks and will lead to issues! - https://github.com/yjs/yjs/issues/438')
 }
 glo[importIdentifier] = true
--- a/src/internals.js
+++ b/src/internals.js
@@ -1,4 +1,3 @@
-
 export * from './utils/AbstractConnector.js'
 export * from './utils/DeleteSet.js'
 export * from './utils/Doc.js'
--- a/src/structs/AbstractStruct.js
+++ b/src/structs/AbstractStruct.js
@@ -1,4 +1,3 @@
-
 import {
  UpdateEncoderV1, UpdateEncoderV2, ID, Transaction // eslint-disable-line
 } from '../internals.js'
--- a/src/structs/ContentDeleted.js
+++ b/src/structs/ContentDeleted.js
@@ -1,4 +1,3 @@
-
 import {
  addToDeleteSet,
  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, StructStore, Item, Transaction // eslint-disable-line
--- a/src/structs/ContentDoc.js
+++ b/src/structs/ContentDoc.js
@@ -1,4 +1,3 @@
-
 import {
  Doc, UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, StructStore, Transaction, Item // eslint-disable-line
 } from '../internals.js'
--- a/src/structs/ContentEmbed.js
+++ b/src/structs/ContentEmbed.js
@@ -1,4 +1,3 @@
-
 import {
  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, StructStore, Item, Transaction // eslint-disable-line
 } from '../internals.js'
--- a/src/structs/ContentFormat.js
+++ b/src/structs/ContentFormat.js
@@ -1,6 +1,5 @@
-
 import {
-  AbstractType, UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, Item, StructStore, Transaction // eslint-disable-line
+  YText, UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, Item, StructStore, Transaction // eslint-disable-line
 } from '../internals.js'

 import * as error from 'lib0/error'
@@ -47,28 +46,30 @@ export class ContentFormat {
  }

  /**
-   * @param {number} offset
+   * @param {number} _offset
   * @return {ContentFormat}
   */
-  splice (offset) {
+  splice (_offset) {
    throw error.methodUnimplemented()
  }

  /**
-   * @param {ContentFormat} right
+   * @param {ContentFormat} _right
   * @return {boolean}
   */
-  mergeWith (right) {
+  mergeWith (_right) {
    return false
  }

  /**
-   * @param {Transaction} transaction
+   * @param {Transaction} _transaction
   * @param {Item} item
   */
-  integrate (transaction, item) {
+  integrate (_transaction, item) {
    // @todo searchmarker are currently unsupported for rich text documents
-    /** @type {AbstractType<any>} */ (item.parent)._searchMarker = null
+    const p = /** @type {YText} */ (item.parent)
+    p._searchMarker = null
+    p._hasFormatting = true
  }

  /**
--- a/src/structs/ContentType.js
+++ b/src/structs/ContentType.js
@@ -1,4 +1,3 @@
-
 import {
  readYArray,
  readYMap,
@@ -108,7 +107,7 @@ export class ContentType {
    while (item !== null) {
      if (!item.deleted) {
        item.delete(transaction)
-      } else {
+      } else if (item.id.clock < (transaction.beforeState.get(item.id.client) || 0)) {
        // This will be gc'd later and we want to merge it if possible
        // We try to merge all deleted items after each transaction,
        // but we have no knowledge about that this needs to be merged
@@ -120,7 +119,7 @@ export class ContentType {
    this.type._map.forEach(item => {
      if (!item.deleted) {
        item.delete(transaction)
-      } else {
+      } else if (item.id.clock < (transaction.beforeState.get(item.id.client) || 0)) {
        // same as above
        transaction._mergeStructs.push(item)
      }
--- a/src/structs/GC.js
+++ b/src/structs/GC.js
@@ -1,4 +1,3 @@
-
 import {
  AbstractStruct,
  addStruct,
--- a/src/structs/Item.js
+++ b/src/structs/Item.js
@@ -1,4 +1,3 @@
-
 import {
  GC,
  getState,
@@ -23,11 +22,12 @@ import {
  readContentType,
  addChangedTypeToTransaction,
  isDeleted,
-  DeleteSet, UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, ContentType, ContentDeleted, StructStore, ID, AbstractType, Transaction // eslint-disable-line
+  StackItem, DeleteSet, UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, ContentType, ContentDeleted, StructStore, ID, AbstractType, Transaction // eslint-disable-line
 } from '../internals.js'

 import * as error from 'lib0/error'
 import * as binary from 'lib0/binary'
+import * as array from 'lib0/array'

 /**
 * @todo This should return several items
@@ -120,6 +120,12 @@ export const splitItem = (transaction, leftItem, diff) => {
  return rightItem
 }

+/**
+ * @param {Array<StackItem>} stack
+ * @param {ID} id
+ */
+const isDeletedByUndoStack = (stack, id) => array.some(stack, /** @param {StackItem} s */ s => isDeleted(s.deletions, id))
+
 /**
 * Redoes the effect of this operation.
 *
@@ -128,12 +134,13 @@ export const splitItem = (transaction, leftItem, diff) => {
 * @param {Set<Item>} redoitems
 * @param {DeleteSet} itemsToDelete
 * @param {boolean} ignoreRemoteMapChanges
+ * @param {import('../utils/UndoManager.js').UndoManager} um
 *
 * @return {Item|null}
 *
 * @private
 */
-export const redoItem = (transaction, item, redoitems, itemsToDelete, ignoreRemoteMapChanges) => {
+export const redoItem = (transaction, item, redoitems, itemsToDelete, ignoreRemoteMapChanges, um) => {
  const doc = transaction.doc
  const store = doc.store
  const ownClientID = doc.clientID
@@ -153,7 +160,7 @@ export const redoItem = (transaction, item, redoitems, itemsToDelete, ignoreRemo
  // make sure that parent is redone
  if (parentItem !== null && parentItem.deleted === true) {
    // try to undo parent if it will be undone anyway
-    if (parentItem.redone === null && (!redoitems.has(parentItem) || redoItem(transaction, parentItem, redoitems, itemsToDelete, ignoreRemoteMapChanges) === null)) {
+    if (parentItem.redone === null && (!redoitems.has(parentItem) || redoItem(transaction, parentItem, redoitems, itemsToDelete, ignoreRemoteMapChanges, um) === null)) {
      return null
    }
    while (parentItem.redone !== null) {
@@ -203,18 +210,10 @@ export const redoItem = (transaction, item, redoitems, itemsToDelete, ignoreRemo
      left = item
      // Iterate right while right is in itemsToDelete
      // If it is intended to delete right while item is redone, we can expect that item should replace right.
-      while (left !== null && left.right !== null && isDeleted(itemsToDelete, left.right.id)) {
+      while (left !== null && left.right !== null && (left.right.redone || isDeleted(itemsToDelete, left.right.id) || isDeletedByUndoStack(um.undoStack, left.right.id) || isDeletedByUndoStack(um.redoStack, left.right.id))) {
        left = left.right
-      }
-      // follow redone
-      // trace redone until parent matches
-      while (left !== null && left.redone !== null) {
-        left = getItemCleanStart(transaction, left.redone)
-      }
-      // check wether we were allowed to follow right (indicating that originally this op was replaced by another item)
-      if (left === null || /** @type {AbstractType<any>} */ (left.parent)._item !== parentItem) {
-        // invalid parent; should never happen
-        return null
+        // follow redone
+        while (left.redone) left = getItemCleanStart(transaction, left.redone)
      }
      if (left && left.right !== null) {
        // It is not possible to redo this item because it conflicts with a
@@ -389,9 +388,8 @@ export class Item extends AbstractStruct {
    }
    if ((this.left && this.left.constructor === GC) || (this.right && this.right.constructor === GC)) {
      this.parent = null
-    }
-    // only set parent if this shouldn't be garbage collected
-    if (!this.parent) {
+    } else if (!this.parent) {
+      // only set parent if this shouldn't be garbage collected
      if (this.left && this.left.constructor === Item) {
        this.parent = this.left.parent
        this.parentSub = this.left.parentSub
@@ -761,48 +759,48 @@ export class AbstractContent {
  }

  /**
-   * @param {number} offset
+   * @param {number} _offset
   * @return {AbstractContent}
   */
-  splice (offset) {
+  splice (_offset) {
    throw error.methodUnimplemented()
  }

  /**
-   * @param {AbstractContent} right
+   * @param {AbstractContent} _right
   * @return {boolean}
   */
-  mergeWith (right) {
+  mergeWith (_right) {
    throw error.methodUnimplemented()
  }

  /**
-   * @param {Transaction} transaction
-   * @param {Item} item
+   * @param {Transaction} _transaction
+   * @param {Item} _item
   */
-  integrate (transaction, item) {
+  integrate (_transaction, _item) {
    throw error.methodUnimplemented()
  }

  /**
-   * @param {Transaction} transaction
+   * @param {Transaction} _transaction
   */
-  delete (transaction) {
+  delete (_transaction) {
    throw error.methodUnimplemented()
  }

  /**
-   * @param {StructStore} store
+   * @param {StructStore} _store
   */
-  gc (store) {
+  gc (_store) {
    throw error.methodUnimplemented()
  }

  /**
-   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
-   * @param {number} offset
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} _encoder
+   * @param {number} _offset
   */
-  write (encoder, offset) {
+  write (_encoder, _offset) {
    throw error.methodUnimplemented()
  }

--- a/src/structs/Skip.js
+++ b/src/structs/Skip.js
@@ -1,4 +1,3 @@
-
 import {
  AbstractStruct,
  UpdateEncoderV1, UpdateEncoderV2, StructStore, Transaction, ID // eslint-disable-line
--- a/src/types/AbstractType.js
+++ b/src/types/AbstractType.js
@@ -1,4 +1,3 @@
-
 import {
  removeEventHandlerListener,
  callEventHandlerListeners,
@@ -324,9 +323,9 @@ export class AbstractType {
  }

  /**
-   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} _encoder
   */
-  _write (encoder) { }
+  _write (_encoder) { }

  /**
   * The first non-deleted item
@@ -344,9 +343,9 @@ export class AbstractType {
   * Must be implemented by each type.
   *
   * @param {Transaction} transaction
-   * @param {Set<null|string>} parentSubs Keys changed on this type. `null` if list was modified.
+   * @param {Set<null|string>} _parentSubs Keys changed on this type. `null` if list was modified.
   */
-  _callObserver (transaction, parentSubs) {
+  _callObserver (transaction, _parentSubs) {
    if (!transaction.local && this._searchMarker) {
      this._searchMarker.length = 0
    }
@@ -683,7 +682,7 @@ export const typeListInsertGenericsAfter = (transaction, parent, referenceItem,
  packJsonContent()
 }

-const lengthExceeded = error.create('Length exceeded!')
+const lengthExceeded = () => error.create('Length exceeded!')

 /**
 * @param {Transaction} transaction
@@ -696,7 +695,7 @@ const lengthExceeded = error.create('Length exceeded!')
 */
 export const typeListInsertGenerics = (transaction, parent, index, content) => {
  if (index > parent._length) {
-    throw lengthExceeded
+    throw lengthExceeded()
  }
  if (index === 0) {
    if (parent._searchMarker) {
@@ -798,7 +797,7 @@ export const typeListDelete = (transaction, parent, index, length) => {
    n = n.right
  }
  if (length > 0) {
-    throw lengthExceeded
+    throw lengthExceeded()
  }
  if (parent._searchMarker) {
    updateMarkerChanges(parent._searchMarker, startIndex, -startLength + length /* in case we remove the above exception */)
@@ -925,6 +924,34 @@ export const typeMapGetSnapshot = (parent, key, snapshot) => {
  return v !== null && isVisible(v, snapshot) ? v.content.getContent()[v.length - 1] : undefined
 }

+/**
+ * @param {AbstractType<any>} parent
+ * @param {Snapshot} snapshot
+ * @return {Object<string,Object<string,any>|number|null|Array<any>|string|Uint8Array|AbstractType<any>|undefined>}
+ *
+ * @private
+ * @function
+ */
+export const typeMapGetAllSnapshot = (parent, snapshot) => {
+  /**
+   * @type {Object<string,any>}
+   */
+  const res = {}
+  parent._map.forEach((value, key) => {
+    /**
+     * @type {Item|null}
+     */
+    let v = value
+    while (v !== null && (!snapshot.sv.has(v.id.client) || v.id.clock >= (snapshot.sv.get(v.id.client) || 0))) {
+      v = v.left
+    }
+    if (v !== null && isVisible(v, snapshot)) {
+      res[key] = v.content.getContent()[v.length - 1]
+    }
+  })
+  return res
+}
+
 /**
 * @param {Map<string,Item>} map
 * @return {IterableIterator<Array<any>>}
--- a/src/types/YArray.js
+++ b/src/types/YArray.js
@@ -58,11 +58,14 @@ export class YArray extends AbstractType {

  /**
   * Construct a new YArray containing the specified items.
-   * @template T
+   * @template {Object<string,any>|Array<any>|number|null|string|Uint8Array} T
   * @param {Array<T>} items
   * @return {YArray<T>}
   */
  static from (items) {
+    /**
+     * @type {YArray<T>}
+     */
    const a = new YArray()
    a.push(items)
    return a
@@ -84,6 +87,9 @@ export class YArray extends AbstractType {
    this._prelimContent = null
  }

+  /**
+   * @return {YArray<T>}
+   */
  _copy () {
    return new YArray()
  }
@@ -92,9 +98,12 @@ export class YArray extends AbstractType {
   * @return {YArray<T>}
   */
  clone () {
+    /**
+     * @type {YArray<T>}
+     */
    const arr = new YArray()
    arr.insert(0, this.toArray().map(el =>
-      el instanceof AbstractType ? el.clone() : el
+      el instanceof AbstractType ? /** @type {typeof el} */ (el.clone()) : el
    ))
    return arr
  }
@@ -133,7 +142,7 @@ export class YArray extends AbstractType {
  insert (index, content) {
    if (this.doc !== null) {
      transact(this.doc, transaction => {
-        typeListInsertGenerics(transaction, this, index, content)
+        typeListInsertGenerics(transaction, this, index, /** @type {any} */ (content))
      })
    } else {
      /** @type {Array<any>} */ (this._prelimContent).splice(index, 0, ...content)
@@ -150,7 +159,7 @@ export class YArray extends AbstractType {
  push (content) {
    if (this.doc !== null) {
      transact(this.doc, transaction => {
-        typeListPushGenerics(transaction, this, content)
+        typeListPushGenerics(transaction, this, /** @type {any} */ (content))
      })
    } else {
      /** @type {Array<any>} */ (this._prelimContent).push(...content)
@@ -235,7 +244,7 @@ export class YArray extends AbstractType {
  }

  /**
-   * Executes a provided function on once on overy element of this YArray.
+   * Executes a provided function once on overy element of this YArray.
   *
   * @param {function(T,number,YArray<T>):void} f A function to execute on every element of this YArray.
   */
@@ -259,9 +268,9 @@ export class YArray extends AbstractType {
 }

 /**
- * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} _decoder
 *
 * @private
 * @function
 */
-export const readYArray = decoder => new YArray()
+export const readYArray = _decoder => new YArray()
--- a/src/types/YMap.js
+++ b/src/types/YMap.js
@@ -1,4 +1,3 @@
-
 /**
 * @module YMap
 */
@@ -41,7 +40,7 @@ export class YMapEvent extends YEvent {
 * A shared Map implementation.
 *
 * @extends AbstractType<YMapEvent<MapType>>
- * @implements {Iterable<MapType>}
+ * @implements {Iterable<[string, MapType]>}
 */
 export class YMap extends AbstractType {
  /**
@@ -81,6 +80,9 @@ export class YMap extends AbstractType {
    this._prelimContent = null
  }

+  /**
+   * @return {YMap<MapType>}
+   */
  _copy () {
    return new YMap()
  }
@@ -89,9 +91,12 @@ export class YMap extends AbstractType {
   * @return {YMap<MapType>}
   */
  clone () {
+    /**
+     * @type {YMap<MapType>}
+     */
    const map = new YMap()
    this.forEach((value, key) => {
-      map.set(key, value instanceof AbstractType ? value.clone() : value)
+      map.set(key, value instanceof AbstractType ? /** @type {typeof value} */ (value.clone()) : value)
    })
    return map
  }
@@ -146,7 +151,7 @@ export class YMap extends AbstractType {
  /**
   * Returns the values for each element in the YMap Type.
   *
-   * @return {IterableIterator<any>}
+   * @return {IterableIterator<MapType>}
   */
  values () {
    return iterator.iteratorMap(createMapIterator(this._map), /** @param {any} v */ v => v[1].content.getContent()[v[1].length - 1])
@@ -155,10 +160,10 @@ export class YMap extends AbstractType {
  /**
   * Returns an Iterator of [key, value] pairs
   *
-   * @return {IterableIterator<any>}
+   * @return {IterableIterator<[string, MapType]>}
   */
  entries () {
-    return iterator.iteratorMap(createMapIterator(this._map), /** @param {any} v */ v => [v[0], v[1].content.getContent()[v[1].length - 1]])
+    return iterator.iteratorMap(createMapIterator(this._map), /** @param {any} v */ v => /** @type {any} */ ([v[0], v[1].content.getContent()[v[1].length - 1]]))
  }

  /**
@@ -167,22 +172,17 @@ export class YMap extends AbstractType {
   * @param {function(MapType,string,YMap<MapType>):void} f A function to execute on every element of this YArray.
   */
  forEach (f) {
-    /**
-     * @type {Object<string,MapType>}
-     */
-    const map = {}
    this._map.forEach((item, key) => {
      if (!item.deleted) {
        f(item.content.getContent()[item.length - 1], key, this)
      }
    })
-    return map
  }

  /**
   * Returns an Iterator of [key, value] pairs
   *
-   * @return {IterableIterator<any>}
+   * @return {IterableIterator<[string, MapType]>}
   */
  [Symbol.iterator] () {
    return this.entries()
@@ -205,14 +205,16 @@ export class YMap extends AbstractType {

  /**
   * Adds or updates an element with a specified key and value.
+   * @template {MapType} VAL
   *
   * @param {string} key The key of the element to add to this YMap
-   * @param {MapType} value The value of the element to add
+   * @param {VAL} value The value of the element to add
+   * @return {VAL}
   */
  set (key, value) {
    if (this.doc !== null) {
      transact(this.doc, transaction => {
-        typeMapSet(transaction, this, key, value)
+        typeMapSet(transaction, this, key, /** @type {any} */ (value))
      })
    } else {
      /** @type {Map<string, any>} */ (this._prelimContent).set(key, value)
@@ -246,7 +248,7 @@ export class YMap extends AbstractType {
  clear () {
    if (this.doc !== null) {
      transact(this.doc, transaction => {
-        this.forEach(function (value, key, map) {
+        this.forEach(function (_value, key, map) {
          typeMapDelete(transaction, map, key)
        })
      })
@@ -264,9 +266,9 @@ export class YMap extends AbstractType {
 }

 /**
- * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} _decoder
 *
 * @private
 * @function
 */
-export const readYMap = decoder => new YMap()
+export const readYMap = _decoder => new YMap()
--- a/src/types/YText.js
+++ b/src/types/YText.js
@@ -1,4 +1,3 @@
-
 /**
 * @module YText
 */
@@ -118,14 +117,15 @@ const findNextPosition = (transaction, pos, count) => {
 * @param {Transaction} transaction
 * @param {AbstractType<any>} parent
 * @param {number} index
+ * @param {boolean} useSearchMarker
 * @return {ItemTextListPosition}
 *
 * @private
 * @function
 */
-const findPosition = (transaction, parent, index) => {
+const findPosition = (transaction, parent, index, useSearchMarker) => {
  const currentAttributes = new Map()
-  const marker = findMarker(parent, index)
+  const marker = useSearchMarker ? findMarker(parent, index) : null
  if (marker) {
    const pos = new ItemTextListPosition(marker.p.left, marker.p, marker.index, currentAttributes)
    return findNextPosition(transaction, pos, index - marker.index)
@@ -251,7 +251,7 @@ const insertAttributes = (transaction, parent, currPos, attributes) => {
 * @function
 **/
 const insertText = (transaction, parent, currPos, text, attributes) => {
-  currPos.currentAttributes.forEach((val, key) => {
+  currPos.currentAttributes.forEach((_val, key) => {
    if (attributes[key] === undefined) {
      attributes[key] = null
    }
@@ -363,33 +363,48 @@ const formatText = (transaction, parent, currPos, length, attributes) => {
 * @function
 */
 const cleanupFormattingGap = (transaction, start, curr, startAttributes, currAttributes) => {
-  let end = curr
-  const endAttributes = map.copy(currAttributes)
+  /**
+   * @type {Item|null}
+   */
+  let end = start
+  /**
+   * @type {Map<string,ContentFormat>}
+   */
+  const endFormats = map.create()
  while (end && (!end.countable || end.deleted)) {
    if (!end.deleted && end.content.constructor === ContentFormat) {
-      updateCurrentAttributes(endAttributes, /** @type {ContentFormat} */ (end.content))
+      const cf = /** @type {ContentFormat} */ (end.content)
+      endFormats.set(cf.key, cf)
    }
    end = end.right
  }
  let cleanups = 0
-  let reachedEndOfCurr = false
+  let reachedCurr = false
  while (start !== end) {
    if (curr === start) {
-      reachedEndOfCurr = true
+      reachedCurr = true
    }
    if (!start.deleted) {
      const content = start.content
      switch (content.constructor) {
        case ContentFormat: {
          const { key, value } = /** @type {ContentFormat} */ (content)
-          if ((endAttributes.get(key) || null) !== value || (startAttributes.get(key) || null) === value) {
+          const startAttrValue = startAttributes.get(key) || null
+          if (endFormats.get(key) !== content || startAttrValue === value) {
            // Either this format is overwritten or it is not necessary because the attribute already existed.
            start.delete(transaction)
            cleanups++
-            if (!reachedEndOfCurr && (currAttributes.get(key) || null) === value && (startAttributes.get(key) || null) !== value) {
-              currAttributes.delete(key)
+            if (!reachedCurr && (currAttributes.get(key) || null) === value && startAttrValue !== value) {
+              if (startAttrValue === null) {
+                currAttributes.delete(key)
+              } else {
+                currAttributes.set(key, startAttrValue)
+              }
            }
          }
+          if (!reachedCurr && !start.deleted) {
+            updateCurrentAttributes(currAttributes, /** @type {ContentFormat} */ (content))
+          }
          break
        }
      }
@@ -461,6 +476,56 @@ export const cleanupYTextFormatting = type => {
  return res
 }

+/**
+ * This will be called by the transction once the event handlers are called to potentially cleanup
+ * formatting attributes.
+ *
+ * @param {Transaction} transaction
+ */
+export const cleanupYTextAfterTransaction = transaction => {
+  /**
+   * @type {Set<YText>}
+   */
+  const needFullCleanup = new Set()
+  // check if another formatting item was inserted
+  const doc = transaction.doc
+  for (const [client, afterClock] of transaction.afterState.entries()) {
+    const clock = transaction.beforeState.get(client) || 0
+    if (afterClock === clock) {
+      continue
+    }
+    iterateStructs(transaction, /** @type {Array<Item|GC>} */ (doc.store.clients.get(client)), clock, afterClock, item => {
+      if (
+        !item.deleted && /** @type {Item} */ (item).content.constructor === ContentFormat && item.constructor !== GC
+      ) {
+        needFullCleanup.add(/** @type {any} */ (item).parent)
+      }
+    })
+  }
+  // cleanup in a new transaction
+  transact(doc, (t) => {
+    iterateDeletedStructs(transaction, transaction.deleteSet, item => {
+      if (item instanceof GC || !(/** @type {YText} */ (item.parent)._hasFormatting) || needFullCleanup.has(/** @type {YText} */ (item.parent))) {
+        return
+      }
+      const parent = /** @type {YText} */ (item.parent)
+      if (item.content.constructor === ContentFormat) {
+        needFullCleanup.add(parent)
+      } else {
+        // If no formatting attribute was inserted or deleted, we can make due with contextless
+        // formatting cleanups.
+        // Contextless: it is not necessary to compute currentAttributes for the affected position.
+        cleanupContextlessFormattingGap(t, item)
+      }
+    })
+    // If a formatting item was inserted, we simply clean the whole type.
+    // We need to compute currentAttributes for the current position anyway.
+    for (const yText of needFullCleanup) {
+      cleanupYTextFormatting(yText)
+    }
+  })
+}
+
 /**
 * @param {Transaction} transaction
 * @param {ItemTextListPosition} currPos
@@ -616,36 +681,39 @@ export class YTextEvent extends YEvent {
            /**
             * @type {any}
             */
-            let op
+            let op = null
            switch (action) {
              case 'delete':
-                op = { delete: deleteLen }
+                if (deleteLen > 0) {
+                  op = { delete: deleteLen }
+                }
                deleteLen = 0
                break
              case 'insert':
-                op = { insert }
-                if (currentAttributes.size > 0) {
-                  op.attributes = {}
-                  currentAttributes.forEach((value, key) => {
-                    if (value !== null) {
-                      op.attributes[key] = value
-                    }
-                  })
+                if (typeof insert === 'object' || insert.length > 0) {
+                  op = { insert }
+                  if (currentAttributes.size > 0) {
+                    op.attributes = {}
+                    currentAttributes.forEach((value, key) => {
+                      if (value !== null) {
+                        op.attributes[key] = value
+                      }
+                    })
+                  }
                }
                insert = ''
                break
              case 'retain':
-                op = { retain }
-                if (Object.keys(attributes).length > 0) {
-                  op.attributes = {}
-                  for (const key in attributes) {
-                    op.attributes[key] = attributes[key]
+                if (retain > 0) {
+                  op = { retain }
+                  if (!object.isEmpty(attributes)) {
+                    op.attributes = object.assign({}, attributes)
                  }
                }
                retain = 0
                break
            }
-            delta.push(op)
+            if (op) delta.push(op)
            action = null
          }
        }
@@ -791,9 +859,14 @@ export class YText extends AbstractType {
     */
    this._pending = string !== undefined ? [() => this.insert(0, string)] : []
    /**
-     * @type {Array<ArraySearchMarker>}
+     * @type {Array<ArraySearchMarker>|null}
     */
    this._searchMarker = []
+    /**
+     * Whether this YText contains formatting attributes.
+     * This flag is updated when a formatting item is integrated (see ContentFormat.integrate)
+     */
+    this._hasFormatting = false
  }

  /**
@@ -841,55 +914,10 @@ export class YText extends AbstractType {
  _callObserver (transaction, parentSubs) {
    super._callObserver(transaction, parentSubs)
    const event = new YTextEvent(this, transaction, parentSubs)
-    const doc = transaction.doc
    callTypeObservers(this, transaction, event)
    // If a remote change happened, we try to cleanup potential formatting duplicates.
-    if (!transaction.local) {
-      // check if another formatting item was inserted
-      let foundFormattingItem = false
-      for (const [client, afterClock] of transaction.afterState.entries()) {
-        const clock = transaction.beforeState.get(client) || 0
-        if (afterClock === clock) {
-          continue
-        }
-        iterateStructs(transaction, /** @type {Array<Item|GC>} */ (doc.store.clients.get(client)), clock, afterClock, item => {
-          if (!item.deleted && /** @type {Item} */ (item).content.constructor === ContentFormat) {
-            foundFormattingItem = true
-          }
-        })
-        if (foundFormattingItem) {
-          break
-        }
-      }
-      if (!foundFormattingItem) {
-        iterateDeletedStructs(transaction, transaction.deleteSet, item => {
-          if (item instanceof GC || foundFormattingItem) {
-            return
-          }
-          if (item.parent === this && item.content.constructor === ContentFormat) {
-            foundFormattingItem = true
-          }
-        })
-      }
-      transact(doc, (t) => {
-        if (foundFormattingItem) {
-          // If a formatting item was inserted, we simply clean the whole type.
-          // We need to compute currentAttributes for the current position anyway.
-          cleanupYTextFormatting(this)
-        } else {
-          // If no formatting attribute was inserted, we can make due with contextless
-          // formatting cleanups.
-          // Contextless: it is not necessary to compute currentAttributes for the affected position.
-          iterateDeletedStructs(t, t.deleteSet, item => {
-            if (item instanceof GC) {
-              return
-            }
-            if (item.parent === this) {
-              cleanupContextlessFormattingGap(t, item)
-            }
-          })
-        }
-      })
+    if (!transaction.local && this._hasFormatting) {
+      transaction._needFormattingCleanup = true
    }
  }

@@ -927,7 +955,7 @@ export class YText extends AbstractType {
   * Apply a {@link Delta} on this shared YText type.
   *
   * @param {any} delta The changes to apply on this element.
-   * @param {object}  [opts]
+   * @param {object}  opts
   * @param {boolean} [opts.sanitize] Sanitize input delta. Removes ending newlines if set to true.
   *
   *
@@ -1003,27 +1031,19 @@ export class YText extends AbstractType {
        str = ''
      }
    }
-    // snapshots are merged again after the transaction, so we need to keep the
-    // transalive until we are done
-    transact(doc, transaction => {
-      if (snapshot) {
-        splitSnapshotAffectedStructs(transaction, snapshot)
-      }
-      if (prevSnapshot) {
-        splitSnapshotAffectedStructs(transaction, prevSnapshot)
-      }
+    const computeDelta = () => {
      while (n !== null) {
        if (isVisible(n, snapshot) || (prevSnapshot !== undefined && isVisible(n, prevSnapshot))) {
          switch (n.content.constructor) {
            case ContentString: {
              const cur = currentAttributes.get('ychange')
              if (snapshot !== undefined && !isVisible(n, snapshot)) {
-                if (cur === undefined || cur.user !== n.id.client || cur.state !== 'removed') {
+                if (cur === undefined || cur.user !== n.id.client || cur.type !== 'removed') {
                  packStr()
                  currentAttributes.set('ychange', computeYChange ? computeYChange('removed', n.id) : { type: 'removed' })
                }
              } else if (prevSnapshot !== undefined && !isVisible(n, prevSnapshot)) {
-                if (cur === undefined || cur.user !== n.id.client || cur.state !== 'added') {
+                if (cur === undefined || cur.user !== n.id.client || cur.type !== 'added') {
                  packStr()
                  currentAttributes.set('ychange', computeYChange ? computeYChange('added', n.id) : { type: 'added' })
                }
@@ -1064,7 +1084,22 @@ export class YText extends AbstractType {
        n = n.right
      }
      packStr()
-    }, splitSnapshotAffectedStructs)
+    }
+    if (snapshot || prevSnapshot) {
+      // snapshots are merged again after the transaction, so we need to keep the
+      // transaction alive until we are done
+      transact(doc, transaction => {
+        if (snapshot) {
+          splitSnapshotAffectedStructs(transaction, snapshot)
+        }
+        if (prevSnapshot) {
+          splitSnapshotAffectedStructs(transaction, prevSnapshot)
+        }
+        computeDelta()
+      }, 'cleanup')
+    } else {
+      computeDelta()
+    }
    return ops
  }

@@ -1085,7 +1120,7 @@ export class YText extends AbstractType {
    const y = this.doc
    if (y !== null) {
      transact(y, transaction => {
-        const pos = findPosition(transaction, this, index)
+        const pos = findPosition(transaction, this, index, !attributes)
        if (!attributes) {
          attributes = {}
          // @ts-ignore
@@ -1103,20 +1138,20 @@ export class YText extends AbstractType {
   *
   * @param {number} index The index to insert the embed at.
   * @param {Object | AbstractType<any>} embed The Object that represents the embed.
-   * @param {TextAttributes} attributes Attribute information to apply on the
+   * @param {TextAttributes} [attributes] Attribute information to apply on the
   *                                    embed
   *
   * @public
   */
-  insertEmbed (index, embed, attributes = {}) {
+  insertEmbed (index, embed, attributes) {
    const y = this.doc
    if (y !== null) {
      transact(y, transaction => {
-        const pos = findPosition(transaction, this, index)
-        insertText(transaction, this, pos, embed, attributes)
+        const pos = findPosition(transaction, this, index, !attributes)
+        insertText(transaction, this, pos, embed, attributes || {})
      })
    } else {
-      /** @type {Array<function>} */ (this._pending).push(() => this.insertEmbed(index, embed, attributes))
+      /** @type {Array<function>} */ (this._pending).push(() => this.insertEmbed(index, embed, attributes || {}))
    }
  }

@@ -1135,7 +1170,7 @@ export class YText extends AbstractType {
    const y = this.doc
    if (y !== null) {
      transact(y, transaction => {
-        deleteText(transaction, findPosition(transaction, this, index), length)
+        deleteText(transaction, findPosition(transaction, this, index, true), length)
      })
    } else {
      /** @type {Array<function>} */ (this._pending).push(() => this.delete(index, length))
@@ -1159,7 +1194,7 @@ export class YText extends AbstractType {
    const y = this.doc
    if (y !== null) {
      transact(y, transaction => {
-        const pos = findPosition(transaction, this, index)
+        const pos = findPosition(transaction, this, index, false)
        if (pos.right === null) {
          return
        }
@@ -1229,12 +1264,11 @@ export class YText extends AbstractType {
   *
   * @note Xml-Text nodes don't have attributes. You can use this feature to assign properties to complete text-blocks.
   *
-   * @param {Snapshot} [snapshot]
   * @return {Object<string, any>} A JSON Object that describes the attributes.
   *
   * @public
   */
-  getAttributes (snapshot) {
+  getAttributes () {
    return typeMapGetAll(this)
  }

@@ -1247,10 +1281,10 @@ export class YText extends AbstractType {
 }

 /**
- * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} _decoder
 * @return {YText}
 *
 * @private
 * @function
 */
-export const readYText = decoder => new YText()
+export const readYText = _decoder => new YText()
--- a/src/types/YXmlElement.js
+++ b/src/types/YXmlElement.js
@@ -1,3 +1,4 @@
+import * as object from 'lib0/object'

 import {
  YXmlFragment,
@@ -7,17 +8,24 @@ import {
  typeMapSet,
  typeMapGet,
  typeMapGetAll,
+  typeMapGetAllSnapshot,
  typeListForEach,
  YXmlElementRefID,
-  YXmlText, ContentType, AbstractType, UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, Snapshot, Doc, Item // eslint-disable-line
+  Snapshot, YXmlText, ContentType, AbstractType, UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, Doc, Item // eslint-disable-line
 } from '../internals.js'

+/**
+ * @typedef {Object|number|null|Array<any>|string|Uint8Array|AbstractType<any>} ValueTypes
+ */
+
 /**
 * 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
+ *
+ * @template {{ [key: string]: ValueTypes }} [KV={ [key: string]: string }]
 */
 export class YXmlElement extends YXmlFragment {
  constructor (nodeName = 'UNDEFINED') {
@@ -73,14 +81,19 @@ export class YXmlElement extends YXmlFragment {
  }

  /**
-   * @return {YXmlElement}
+   * @return {YXmlElement<KV>}
   */
  clone () {
+    /**
+     * @type {YXmlElement<KV>}
+     */
    const el = new YXmlElement(this.nodeName)
    const attrs = this.getAttributes()
-    for (const key in attrs) {
-      el.setAttribute(key, attrs[key])
-    }
+    object.forEach(attrs, (value, key) => {
+      if (typeof value === 'string') {
+        el.setAttribute(key, value)
+      }
+    })
    // @ts-ignore
    el.insert(0, this.toArray().map(item => item instanceof AbstractType ? item.clone() : item))
    return el
@@ -116,7 +129,7 @@ export class YXmlElement extends YXmlFragment {
  /**
   * Removes an attribute from this YXmlElement.
   *
-   * @param {String} attributeName The attribute name that is to be removed.
+   * @param {string} attributeName The attribute name that is to be removed.
   *
   * @public
   */
@@ -133,8 +146,10 @@ export class YXmlElement extends YXmlFragment {
  /**
   * 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.
+   * @template {keyof KV & string} KEY
+   *
+   * @param {KEY} attributeName The attribute name that is to be set.
+   * @param {KV[KEY]} attributeValue The attribute value that is to be set.
   *
   * @public
   */
@@ -151,9 +166,11 @@ export class YXmlElement extends YXmlFragment {
  /**
   * Returns an attribute value that belongs to the attribute name.
   *
-   * @param {String} attributeName The attribute name that identifies the
+   * @template {keyof KV & string} KEY
+   *
+   * @param {KEY} attributeName The attribute name that identifies the
   *                               queried value.
-   * @return {String} The queried attribute value.
+   * @return {KV[KEY]|undefined} The queried attribute value.
   *
   * @public
   */
@@ -164,7 +181,7 @@ export class YXmlElement extends YXmlFragment {
  /**
   * Returns whether an attribute exists
   *
-   * @param {String} attributeName The attribute name to check for existence.
+   * @param {string} attributeName The attribute name to check for existence.
   * @return {boolean} whether the attribute exists.
   *
   * @public
@@ -177,12 +194,12 @@ export class YXmlElement extends YXmlFragment {
   * Returns all attribute name/value pairs in a JSON Object.
   *
   * @param {Snapshot} [snapshot]
-   * @return {Object<string, any>} A JSON Object that describes the attributes.
+   * @return {{ [Key in Extract<keyof KV,string>]?: KV[Key]}} A JSON Object that describes the attributes.
   *
   * @public
   */
  getAttributes (snapshot) {
-    return typeMapGetAll(this)
+    return /** @type {any} */ (snapshot ? typeMapGetAllSnapshot(this, snapshot) : typeMapGetAll(this))
  }

  /**
@@ -204,7 +221,10 @@ export class YXmlElement extends YXmlFragment {
    const dom = _document.createElement(this.nodeName)
    const attrs = this.getAttributes()
    for (const key in attrs) {
-      dom.setAttribute(key, attrs[key])
+      const value = attrs[key]
+      if (typeof value === 'string') {
+        dom.setAttribute(key, value)
+      }
    }
    typeListForEach(this, yxml => {
      dom.appendChild(yxml.toDOM(_document, hooks, binding))
--- a/src/types/YXmlEvent.js
+++ b/src/types/YXmlEvent.js
@@ -1,4 +1,3 @@
-
 import {
  YEvent,
  YXmlText, YXmlElement, YXmlFragment, Transaction // eslint-disable-line
--- a/src/types/YXmlFragment.js
+++ b/src/types/YXmlFragment.js
@@ -17,10 +17,11 @@ import {
  transact,
  typeListGet,
  typeListSlice,
-  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, Doc, ContentType, Transaction, Item, YXmlText, YXmlHook, Snapshot // eslint-disable-line
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, Doc, ContentType, Transaction, Item, YXmlText, YXmlHook // eslint-disable-line
 } from '../internals.js'

 import * as error from 'lib0/error'
+import * as array from 'lib0/array'

 /**
 * Define the elements to which a set of CSS queries apply.
@@ -237,7 +238,7 @@ export class YXmlFragment extends AbstractType {
  querySelectorAll (query) {
    query = query.toUpperCase()
    // @ts-ignore
-    return Array.from(new YXmlTreeWalker(this, element => element.nodeName && element.nodeName.toUpperCase() === query))
+    return array.from(new YXmlTreeWalker(this, element => element.nodeName && element.nodeName.toUpperCase() === query))
  }

  /**
@@ -407,7 +408,7 @@ export class YXmlFragment extends AbstractType {
  /**
   * Executes a provided function on once on overy child element.
   *
-   * @param {function(YXmlElement|YXmlText,number, typeof this):void} f A function to execute on every element of this YArray.
+   * @param {function(YXmlElement|YXmlText,number, typeof self):void} f A function to execute on every element of this YArray.
   */
  forEach (f) {
    typeListForEach(this, f)
@@ -427,10 +428,10 @@ export class YXmlFragment extends AbstractType {
 }

 /**
- * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} _decoder
 * @return {YXmlFragment}
 *
 * @private
 * @function
 */
-export const readYXmlFragment = decoder => new YXmlFragment()
+export const readYXmlFragment = _decoder => new YXmlFragment()
--- a/src/types/YXmlHook.js
+++ b/src/types/YXmlHook.js
@@ -1,4 +1,3 @@
-
 import {
  YMap,
  YXmlHookRefID,
--- a/src/types/YXmlText.js
+++ b/src/types/YXmlText.js
@@ -1,4 +1,3 @@
-
 import {
  YText,
  YXmlTextRefID,
--- a/src/utils/AbstractConnector.js
+++ b/src/utils/AbstractConnector.js
@@ -1,4 +1,3 @@
-
 import { Observable } from 'lib0/observable'

 import {
--- a/src/utils/DeleteSet.js
+++ b/src/utils/DeleteSet.js
@@ -1,4 +1,3 @@
-
 import {
  findIndexSS,
  getState,
@@ -171,7 +170,7 @@ export const mergeDeleteSets = dss => {
 * @function
 */
 export const addToDeleteSet = (ds, client, clock, length) => {
-  map.setIfUndefined(ds.clients, client, () => []).push(new DeleteItem(clock, length))
+  map.setIfUndefined(ds.clients, client, () => /** @type {Array<DeleteItem>} */ ([])).push(new DeleteItem(clock, length))
 }

 export const createDeleteSet = () => new DeleteSet()
@@ -219,17 +218,21 @@ export const createDeleteSetFromStructStore = ss => {
 */
 export const writeDeleteSet = (encoder, ds) => {
  encoding.writeVarUint(encoder.restEncoder, ds.clients.size)
-  ds.clients.forEach((dsitems, client) => {
-    encoder.resetDsCurVal()
-    encoding.writeVarUint(encoder.restEncoder, client)
-    const len = dsitems.length
-    encoding.writeVarUint(encoder.restEncoder, len)
-    for (let i = 0; i < len; i++) {
-      const item = dsitems[i]
-      encoder.writeDsClock(item.clock)
-      encoder.writeDsLen(item.len)
-    }
-  })
+
+  // Ensure that the delete set is written in a deterministic order
+  array.from(ds.clients.entries())
+    .sort((a, b) => b[0] - a[0])
+    .forEach(([client, dsitems]) => {
+      encoder.resetDsCurVal()
+      encoding.writeVarUint(encoder.restEncoder, client)
+      const len = dsitems.length
+      encoding.writeVarUint(encoder.restEncoder, len)
+      for (let i = 0; i < len; i++) {
+        const item = dsitems[i]
+        encoder.writeDsClock(item.clock)
+        encoder.writeDsLen(item.len)
+      }
+    })
 }

 /**
@@ -247,7 +250,7 @@ export const readDeleteSet = decoder => {
    const client = decoding.readVarUint(decoder.restDecoder)
    const numberOfDeletes = decoding.readVarUint(decoder.restDecoder)
    if (numberOfDeletes > 0) {
-      const dsField = map.setIfUndefined(ds.clients, client, () => [])
+      const dsField = map.setIfUndefined(ds.clients, client, () => /** @type {Array<DeleteItem>} */ ([]))
      for (let i = 0; i < numberOfDeletes; i++) {
        dsField.push(new DeleteItem(decoder.readDsClock(), decoder.readDsLen()))
      }
@@ -324,3 +327,23 @@ export const readAndApplyDeleteSet = (decoder, transaction, store) => {
  }
  return null
 }
+
+/**
+ * @param {DeleteSet} ds1
+ * @param {DeleteSet} ds2
+ */
+export const equalDeleteSets = (ds1, ds2) => {
+  if (ds1.clients.size !== ds2.clients.size) return false
+  for (const [client, deleteItems1] of ds1.clients.entries()) {
+    const deleteItems2 = /** @type {Array<import('../internals.js').DeleteItem>} */ (ds2.clients.get(client))
+    if (deleteItems2 === undefined || deleteItems1.length !== deleteItems2.length) return false
+    for (let i = 0; i < deleteItems1.length; i++) {
+      const di1 = deleteItems1[i]
+      const di2 = deleteItems2[i]
+      if (di1.clock !== di2.clock || di1.len !== di2.len) {
+        return false
+      }
+    }
+  }
+  return true
+}
--- a/src/utils/Doc.js
+++ b/src/utils/Doc.js
@@ -38,7 +38,7 @@ export const generateNewClientId = random.uint32
 */
 export class Doc extends Observable {
  /**
-   * @param {DocOpts} [opts] configuration
+   * @param {DocOpts} opts configuration
   */
  constructor ({ guid = random.uuidv4(), collectionid = null, gc = true, gcFilter = () => true, meta = null, autoLoad = false, shouldLoad = true } = {}) {
    super()
@@ -72,13 +72,57 @@ export class Doc extends Observable {
    this.shouldLoad = shouldLoad
    this.autoLoad = autoLoad
    this.meta = meta
+    /**
+     * This is set to true when the persistence provider loaded the document from the database or when the `sync` event fires.
+     * Note that not all providers implement this feature. Provider authors are encouraged to fire the `load` event when the doc content is loaded from the database.
+     *
+     * @type {boolean}
+     */
    this.isLoaded = false
+    /**
+     * This is set to true when the connection provider has successfully synced with a backend.
+     * Note that when using peer-to-peer providers this event may not provide very useful.
+     * Also note that not all providers implement this feature. Provider authors are encouraged to fire
+     * the `sync` event when the doc has been synced (with `true` as a parameter) or if connection is
+     * lost (with false as a parameter).
+     */
+    this.isSynced = false
+    /**
+     * Promise that resolves once the document has been loaded from a presistence provider.
+     */
    this.whenLoaded = promise.create(resolve => {
      this.on('load', () => {
        this.isLoaded = true
        resolve(this)
      })
    })
+    const provideSyncedPromise = () => promise.create(resolve => {
+      /**
+       * @param {boolean} isSynced
+       */
+      const eventHandler = (isSynced) => {
+        if (isSynced === undefined || isSynced === true) {
+          this.off('sync', eventHandler)
+          resolve()
+        }
+      }
+      this.on('sync', eventHandler)
+    })
+    this.on('sync', isSynced => {
+      if (isSynced === false && this.isSynced) {
+        this.whenSynced = provideSyncedPromise()
+      }
+      this.isSynced = isSynced === undefined || isSynced === true
+      if (this.isSynced && !this.isLoaded) {
+        this.emit('load', [])
+      }
+    })
+    /**
+     * Promise that resolves once the document has been synced with a backend.
+     * This promise is recreated when the connection is lost.
+     * Note the documentation about the `isSynced` property.
+     */
+    this.whenSynced = provideSyncedPromise()
  }

  /**
@@ -103,7 +147,7 @@ export class Doc extends Observable {
  }

  getSubdocGuids () {
-    return new Set(Array.from(this.subdocs).map(doc => doc.guid))
+    return new Set(array.from(this.subdocs).map(doc => doc.guid))
  }

  /**
@@ -112,13 +156,15 @@ export class Doc extends Observable {
   * 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
+   * @template T
+   * @param {function(Transaction):T} f The function that should be executed as a transaction
   * @param {any} [origin] Origin of who started the transaction. Will be stored on transaction.origin
+   * @return T
   *
   * @public
   */
  transact (f, origin = null) {
-    transact(this, f, origin)
+    return transact(this, f, origin)
  }

  /**
--- a/src/utils/ID.js
+++ b/src/utils/ID.js
@@ -1,4 +1,3 @@
-
 import { AbstractType } from '../internals.js' // eslint-disable-line

 import * as decoding from 'lib0/decoding'
--- a/src/utils/PermanentUserData.js
+++ b/src/utils/PermanentUserData.js
@@ -1,4 +1,3 @@
-
 import {
  YArray,
  YMap,
@@ -71,7 +70,7 @@ export class PermanentUserData {
   * @param {Doc} doc
   * @param {number} clientid
   * @param {string} userDescription
-   * @param {Object} [conf]
+   * @param {Object} conf
   * @param {function(Transaction, DeleteSet):boolean} [conf.filter]
   */
  setUserMapping (doc, clientid, userDescription, { filter = () => true } = {}) {
@@ -84,7 +83,7 @@ export class PermanentUserData {
      users.set(userDescription, user)
    }
    user.get('ids').push([clientid])
-    users.observe(event => {
+    users.observe(_event => {
      setTimeout(() => {
        const userOverwrite = users.get(userDescription)
        if (userOverwrite !== user) {
--- a/src/utils/RelativePosition.js
+++ b/src/utils/RelativePosition.js
@@ -1,4 +1,3 @@
-
 import {
  writeID,
  readID,
--- a/src/utils/Snapshot.js
+++ b/src/utils/Snapshot.js
@@ -1,4 +1,3 @@
-
 import {
  isDeleted,
  createDeleteSetFromStructStore,
@@ -15,7 +14,10 @@ import {
  findIndexSS,
  UpdateEncoderV2,
  applyUpdateV2,
-  DSEncoderV1, DSEncoderV2, DSDecoderV1, DSDecoderV2, Transaction, Doc, DeleteSet, Item // eslint-disable-line
+  LazyStructReader,
+  equalDeleteSets,
+  UpdateDecoderV1, UpdateDecoderV2, DSEncoderV1, DSEncoderV2, DSDecoderV1, DSDecoderV2, Transaction, Doc, DeleteSet, Item, // eslint-disable-line
+  mergeDeleteSets
 } from '../internals.js'

 import * as map from 'lib0/map'
@@ -147,12 +149,20 @@ export const splitSnapshotAffectedStructs = (transaction, snapshot) => {
        getItemCleanStart(transaction, createID(client, clock))
      }
    })
-    iterateDeletedStructs(transaction, snapshot.ds, item => {})
+    iterateDeletedStructs(transaction, snapshot.ds, _item => {})
    meta.add(snapshot)
  }
 }

 /**
+ * @example
+ *  const ydoc = new Y.Doc({ gc: false })
+ *  ydoc.getText().insert(0, 'world!')
+ *  const snapshot = Y.snapshot(ydoc)
+ *  ydoc.getText().insert(0, 'hello ')
+ *  const restored = Y.createDocFromSnapshot(ydoc, snapshot)
+ *  assert(restored.getText().toString() === 'world!')
+ *
 * @param {Doc} originDoc
 * @param {Snapshot} snapshot
 * @param {Doc} [newDoc] Optionally, you may define the Yjs document that receives the data from originDoc
@@ -161,7 +171,7 @@ export const splitSnapshotAffectedStructs = (transaction, snapshot) => {
 export const createDocFromSnapshot = (originDoc, snapshot, newDoc = new Doc()) => {
  if (originDoc.gc) {
    // we should not try to restore a GC-ed document, because some of the restored items might have their content deleted
-    throw new Error('originDoc must not be garbage collected')
+    throw new Error('Garbage-collection must be disabled in `originDoc`!')
  }
  const { sv, ds } = snapshot

@@ -199,3 +209,28 @@ export const createDocFromSnapshot = (originDoc, snapshot, newDoc = new Doc()) =
  applyUpdateV2(newDoc, encoder.toUint8Array(), 'snapshot')
  return newDoc
 }
+
+/**
+ * @param {Snapshot} snapshot
+ * @param {Uint8Array} update
+ * @param {typeof UpdateDecoderV2 | typeof UpdateDecoderV1} [YDecoder]
+ */
+export const snapshotContainsUpdateV2 = (snapshot, update, YDecoder = UpdateDecoderV2) => {
+  const structs = []
+  const updateDecoder = new YDecoder(decoding.createDecoder(update))
+  const lazyDecoder = new LazyStructReader(updateDecoder, false)
+  for (let curr = lazyDecoder.curr; curr !== null; curr = lazyDecoder.next()) {
+    structs.push(curr)
+    if ((snapshot.sv.get(curr.id.client) || 0) < curr.id.clock + curr.length) {
+      return false
+    }
+  }
+  const mergedDS = mergeDeleteSets([snapshot.ds, readDeleteSet(updateDecoder)])
+  return equalDeleteSets(snapshot.ds, mergedDS)
+}
+
+/**
+ * @param {Snapshot} snapshot
+ * @param {Uint8Array} update
+ */
+export const snapshotContainsUpdate = (snapshot, update) => snapshotContainsUpdateV2(snapshot, update, UpdateDecoderV1)
--- a/src/utils/StructStore.js
+++ b/src/utils/StructStore.js
@@ -1,4 +1,3 @@
-
 import {
  GC,
  splitItem,
--- a/src/utils/Transaction.js
+++ b/src/utils/Transaction.js
@@ -1,4 +1,3 @@
-
 import {
  getState,
  writeStructsFromTransaction,
@@ -11,6 +10,7 @@ import {
  Item,
  generateNewClientId,
  createID,
+  cleanupYTextAfterTransaction,
  UpdateEncoderV1, UpdateEncoderV2, GC, StructStore, AbstractType, AbstractStruct, YEvent, Doc // eslint-disable-line
 } from '../internals.js'

@@ -114,6 +114,10 @@ export class Transaction {
     * @type {Set<Doc>}
     */
    this.subdocsLoaded = new Set()
+    /**
+     * @type {boolean}
+     */
+    this._needFormattingCleanup = false
  }
 }

@@ -161,18 +165,29 @@ export const addChangedTypeToTransaction = (transaction, type, parentSub) => {
 /**
 * @param {Array<AbstractStruct>} structs
 * @param {number} pos
+ * @return {number} # of merged structs
 */
-const tryToMergeWithLeft = (structs, pos) => {
-  const left = structs[pos - 1]
-  const right = structs[pos]
-  if (left.deleted === right.deleted && left.constructor === right.constructor) {
-    if (left.mergeWith(right)) {
-      structs.splice(pos, 1)
-      if (right instanceof Item && right.parentSub !== null && /** @type {AbstractType<any>} */ (right.parent)._map.get(right.parentSub) === right) {
-        /** @type {AbstractType<any>} */ (right.parent)._map.set(right.parentSub, /** @type {Item} */ (left))
+const tryToMergeWithLefts = (structs, pos) => {
+  let right = structs[pos]
+  let left = structs[pos - 1]
+  let i = pos
+  for (; i > 0; right = left, left = structs[--i - 1]) {
+    if (left.deleted === right.deleted && left.constructor === right.constructor) {
+      if (left.mergeWith(right)) {
+        if (right instanceof Item && right.parentSub !== null && /** @type {AbstractType<any>} */ (right.parent)._map.get(right.parentSub) === right) {
+          /** @type {AbstractType<any>} */ (right.parent)._map.set(right.parentSub, /** @type {Item} */ (left))
+        }
+        continue
      }
    }
+    break
  }
+  const merged = pos - i
+  if (merged) {
+    // remove all merged structs from the array
+    structs.splice(pos + 1 - merged, merged)
+  }
+  return merged
 }

 /**
@@ -219,9 +234,9 @@ const tryMergeDeleteSet = (ds, store) => {
      for (
        let si = mostRightIndexToCheck, struct = structs[si];
        si > 0 && struct.id.clock >= deleteItem.clock;
-        struct = structs[--si]
+        struct = structs[si]
      ) {
-        tryToMergeWithLeft(structs, si)
+        si -= 1 + tryToMergeWithLefts(structs, si)
      }
    }
  })
@@ -251,7 +266,6 @@ const cleanupTransactions = (transactionCleanups, i) => {
    try {
      sortAndMergeDeleteSet(ds)
      transaction.afterState = getStateVector(transaction.doc.store)
-      doc._transaction = null
      doc.emit('beforeObserverCalls', [transaction, doc])
      /**
       * An array of event callbacks.
@@ -271,31 +285,34 @@ const cleanupTransactions = (transactionCleanups, i) => {
      )
      fs.push(() => {
        // deep observe events
-        transaction.changedParentTypes.forEach((events, type) =>
-          fs.push(() => {
-            // We need to think about the possibility that the user transforms the
-            // Y.Doc in the event.
-            if (type._item === null || !type._item.deleted) {
-              events = events
-                .filter(event =>
-                  event.target._item === null || !event.target._item.deleted
-                )
-              events
-                .forEach(event => {
-                  event.currentTarget = type
-                })
-              // sort events by path length so that top-level events are fired first.
-              events
-                .sort((event1, event2) => event1.path.length - event2.path.length)
-              // We don't need to check for events.length
-              // because we know it has at least one element
-              callEventHandlerListeners(type._dEH, events, transaction)
-            }
-          })
-        )
-        fs.push(() => doc.emit('afterTransaction', [transaction, doc]))
+        transaction.changedParentTypes.forEach((events, type) => {
+          // We need to think about the possibility that the user transforms the
+          // Y.Doc in the event.
+          if (type._dEH.l.length > 0 && (type._item === null || !type._item.deleted)) {
+            events = events
+              .filter(event =>
+                event.target._item === null || !event.target._item.deleted
+              )
+            events
+              .forEach(event => {
+                event.currentTarget = type
+                // path is relative to the current target
+                event._path = null
+              })
+            // sort events by path length so that top-level events are fired first.
+            events
+              .sort((event1, event2) => event1.path.length - event2.path.length)
+            // We don't need to check for events.length
+            // because we know it has at least one element
+            callEventHandlerListeners(type._dEH, events, transaction)
+          }
+        })
      })
+      fs.push(() => doc.emit('afterTransaction', [transaction, doc]))
      callAll(fs, [])
+      if (transaction._needFormattingCleanup) {
+        cleanupYTextAfterTransaction(transaction)
+      }
    } finally {
      // Replace deleted items with ItemDeleted / GC.
      // This is where content is actually remove from the Yjs Doc.
@@ -311,23 +328,25 @@ const cleanupTransactions = (transactionCleanups, i) => {
          const structs = /** @type {Array<GC|Item>} */ (store.clients.get(client))
          // we iterate from right to left so we can safely remove entries
          const firstChangePos = math.max(findIndexSS(structs, beforeClock), 1)
-          for (let i = structs.length - 1; i >= firstChangePos; i--) {
-            tryToMergeWithLeft(structs, i)
+          for (let i = structs.length - 1; i >= firstChangePos;) {
+            i -= 1 + tryToMergeWithLefts(structs, i)
          }
        }
      })
      // try to merge mergeStructs
      // @todo: it makes more sense to transform mergeStructs to a DS, sort it, and merge from right to left
      //        but at the moment DS does not handle duplicates
-      for (let i = 0; i < mergeStructs.length; i++) {
+      for (let i = mergeStructs.length - 1; i >= 0; i--) {
        const { client, clock } = mergeStructs[i].id
        const structs = /** @type {Array<GC|Item>} */ (store.clients.get(client))
        const replacedStructPos = findIndexSS(structs, clock)
        if (replacedStructPos + 1 < structs.length) {
-          tryToMergeWithLeft(structs, replacedStructPos + 1)
+          if (tryToMergeWithLefts(structs, replacedStructPos + 1) > 1) {
+            continue // no need to perform next check, both are already merged
+          }
        }
        if (replacedStructPos > 0) {
-          tryToMergeWithLeft(structs, replacedStructPos)
+          tryToMergeWithLefts(structs, replacedStructPos)
        }
      }
      if (!transaction.local && transaction.afterState.get(doc.clientID) !== transaction.beforeState.get(doc.clientID)) {
@@ -377,15 +396,21 @@ const cleanupTransactions = (transactionCleanups, i) => {
 /**
 * Implements the functionality of `y.transact(()=>{..})`
 *
+ * @template T
 * @param {Doc} doc
- * @param {function(Transaction):void} f
+ * @param {function(Transaction):T} f
 * @param {any} [origin=true]
+ * @return {T}
 *
 * @function
 */
 export const transact = (doc, f, origin = null, local = true) => {
  const transactionCleanups = doc._transactionCleanups
  let initialCall = false
+  /**
+   * @type {any}
+   */
+  let result = null
  if (doc._transaction === null) {
    initialCall = true
    doc._transaction = new Transaction(doc, origin, local)
@@ -396,18 +421,23 @@ export const transact = (doc, f, origin = null, local = true) => {
    doc.emit('beforeTransaction', [doc._transaction, doc])
  }
  try {
-    f(doc._transaction)
+    result = f(doc._transaction)
  } finally {
-    if (initialCall && transactionCleanups[0] === doc._transaction) {
-      // The first transaction ended, now process observer calls.
-      // Observer call may create new transactions for which we need to call the observers and do cleanup.
-      // We don't want to nest these calls, so we execute these calls one after
-      // another.
-      // Also we need to ensure that all cleanups are called, even if the
-      // observes throw errors.
-      // This file is full of hacky try {} finally {} blocks to ensure that an
-      // event can throw errors and also that the cleanup is called.
-      cleanupTransactions(transactionCleanups, 0)
+    if (initialCall) {
+      const finishCleanup = doc._transaction === transactionCleanups[0]
+      doc._transaction = null
+      if (finishCleanup) {
+        // The first transaction ended, now process observer calls.
+        // Observer call may create new transactions for which we need to call the observers and do cleanup.
+        // We don't want to nest these calls, so we execute these calls one after
+        // another.
+        // Also we need to ensure that all cleanups are called, even if the
+        // observes throw errors.
+        // This file is full of hacky try {} finally {} blocks to ensure that an
+        // event can throw errors and also that the cleanup is called.
+        cleanupTransactions(transactionCleanups, 0)
+      }
    }
  }
+  return result
 }
--- a/src/utils/UndoManager.js
+++ b/src/utils/UndoManager.js
@@ -10,14 +10,15 @@ import {
  getItemCleanStart,
  isDeleted,
  addToDeleteSet,
-  Transaction, Doc, Item, GC, DeleteSet, AbstractType, YEvent // eslint-disable-line
+  Transaction, Doc, Item, GC, DeleteSet, AbstractType // eslint-disable-line
 } from '../internals.js'

 import * as time from 'lib0/time'
 import * as array from 'lib0/array'
+import * as logging from 'lib0/logging'
 import { Observable } from 'lib0/observable'

-class StackItem {
+export class StackItem {
  /**
   * @param {DeleteSet} deletions
   * @param {DeleteSet} insertions
@@ -101,7 +102,7 @@ const popStackItem = (undoManager, stack, eventType) => {
        }
      })
      itemsToRedo.forEach(struct => {
-        performedChange = redoItem(transaction, struct, itemsToRedo, stackItem.insertions, undoManager.ignoreRemoteMapChanges) !== null || performedChange
+        performedChange = redoItem(transaction, struct, itemsToRedo, stackItem.insertions, undoManager.ignoreRemoteMapChanges, undoManager) !== null || performedChange
      })
      // We want to delete in reverse order so that children are deleted before
      // parents, so we have more information available when items are filtered.
@@ -132,12 +133,14 @@ const popStackItem = (undoManager, stack, eventType) => {
 /**
 * @typedef {Object} UndoManagerOptions
 * @property {number} [UndoManagerOptions.captureTimeout=500]
+ * @property {function(Transaction):boolean} [UndoManagerOptions.captureTransaction] Do not capture changes of a Transaction if result false.
 * @property {function(Item):boolean} [UndoManagerOptions.deleteFilter=()=>true] Sometimes
- * it is necessary to filter whan an Undo/Redo operation can delete. If this
+ * it is necessary to filter what an Undo/Redo operation can delete. If this
 * filter returns false, the type/item won't be deleted even it is in the
 * undo/redo scope.
 * @property {Set<any>} [UndoManagerOptions.trackedOrigins=new Set([null])]
 * @property {boolean} [ignoreRemoteMapChanges] Experimental. By default, the UndoManager will never overwrite remote changes. Enable this property to enable overwriting remote changes on key-value changes (Y.Map, properties on Y.Xml, etc..).
+ * @property {Doc} [doc] The document that this UndoManager operates on. Only needed if typeScope is empty.
 */

 /**
@@ -154,16 +157,25 @@ export class UndoManager extends Observable {
   * @param {AbstractType<any>|Array<AbstractType<any>>} typeScope Accepts either a single type, or an array of types
   * @param {UndoManagerOptions} options
   */
-  constructor (typeScope, { captureTimeout = 500, deleteFilter = () => true, trackedOrigins = new Set([null]), ignoreRemoteMapChanges = false } = {}) {
+  constructor (typeScope, {
+    captureTimeout = 500,
+    captureTransaction = _tr => true,
+    deleteFilter = () => true,
+    trackedOrigins = new Set([null]),
+    ignoreRemoteMapChanges = false,
+    doc = /** @type {Doc} */ (array.isArray(typeScope) ? typeScope[0].doc : typeScope.doc)
+  } = {}) {
    super()
    /**
     * @type {Array<AbstractType<any>>}
     */
    this.scope = []
+    this.doc = doc
    this.addToScope(typeScope)
    this.deleteFilter = deleteFilter
    trackedOrigins.add(this)
    this.trackedOrigins = trackedOrigins
+    this.captureTransaction = captureTransaction
    /**
     * @type {Array<StackItem>}
     */
@@ -179,15 +191,19 @@ export class UndoManager extends Observable {
     */
    this.undoing = false
    this.redoing = false
-    this.doc = /** @type {Doc} */ (this.scope[0].doc)
    this.lastChange = 0
    this.ignoreRemoteMapChanges = ignoreRemoteMapChanges
+    this.captureTimeout = captureTimeout
    /**
     * @param {Transaction} transaction
     */
    this.afterTransactionHandler = transaction => {
      // Only track certain transactions
-      if (!this.scope.some(type => transaction.changedParentTypes.has(type)) || (!this.trackedOrigins.has(transaction.origin) && (!transaction.origin || !this.trackedOrigins.has(transaction.origin.constructor)))) {
+      if (
+        !this.captureTransaction(transaction) ||
+        !this.scope.some(type => transaction.changedParentTypes.has(type)) ||
+        (!this.trackedOrigins.has(transaction.origin) && (!transaction.origin || !this.trackedOrigins.has(transaction.origin.constructor)))
+      ) {
        return
      }
      const undoing = this.undoing
@@ -209,7 +225,7 @@ export class UndoManager extends Observable {
      })
      const now = time.getUnixTime()
      let didAdd = false
-      if (now - this.lastChange < captureTimeout && stack.length > 0 && !undoing && !redoing) {
+      if (this.lastChange > 0 && now - this.lastChange < this.captureTimeout && stack.length > 0 && !undoing && !redoing) {
        // append change to last stack op
        const lastOp = stack[stack.length - 1]
        lastOp.deletions = mergeDeleteSets([lastOp.deletions, transaction.deleteSet])
@@ -248,6 +264,7 @@ export class UndoManager extends Observable {
    ytypes = array.isArray(ytypes) ? ytypes : [ytypes]
    ytypes.forEach(ytype => {
      if (this.scope.every(yt => yt !== ytype)) {
+        if (ytype.doc !== this.doc) logging.warn('[yjs#509] Not same Y.Doc') // use MultiDocUndoManager instead. also see https://github.com/yjs/yjs/issues/509
        this.scope.push(ytype)
      }
    })
--- a/src/utils/UpdateEncoder.js
+++ b/src/utils/UpdateEncoder.js
@@ -1,4 +1,3 @@
-
 import * as error from 'lib0/error'
 import * as encoding from 'lib0/encoding'

--- a/src/utils/YEvent.js
+++ b/src/utils/YEvent.js
@@ -1,4 +1,3 @@
-
 import {
  isDeleted,
  Item, AbstractType, Transaction, AbstractStruct // eslint-disable-line
@@ -6,6 +5,9 @@ import {

 import * as set from 'lib0/set'
 import * as array from 'lib0/array'
+import * as error from 'lib0/error'
+
+const errorComputeChanges = 'You must not compute changes after the event-handler fired.'

 /**
 * @template {AbstractType<any>} T
@@ -44,6 +46,10 @@ export class YEvent {
     * @type {null | Array<{ insert?: string | Array<any> | object | AbstractType<any>, retain?: number, delete?: number, attributes?: Object<string, any> }>}
     */
    this._delta = null
+    /**
+     * @type {Array<string|number>|null}
+     */
+    this._path = null
  }

  /**
@@ -60,8 +66,7 @@ export class YEvent {
   *   type === event.target // => true
   */
  get path () {
-    // @ts-ignore _item is defined because target is integrated
-    return getPathTo(this.currentTarget, this.target)
+    return this._path || (this._path = getPathTo(this.currentTarget, this.target))
  }

  /**
@@ -81,6 +86,9 @@ export class YEvent {
   */
  get keys () {
    if (this._keys === null) {
+      if (this.transaction.doc._transactionCleanups.length === 0) {
+        throw error.create(errorComputeChanges)
+      }
      const keys = new Map()
      const target = this.target
      const changed = /** @type Set<string|null> */ (this.transaction.changed.get(target))
@@ -130,6 +138,11 @@ export class YEvent {
  }

  /**
+   * This is a computed property. Note that this can only be safely computed during the
+   * event call. Computing this property after other changes happened might result in
+   * unexpected behavior (incorrect computation of deltas). A safe way to collect changes
+   * is to store the `changes` or the `delta` object. Avoid storing the `transaction` object.
+   *
   * @type {Array<{insert?: string | Array<any> | object | AbstractType<any>, retain?: number, delete?: number, attributes?: Object<string, any>}>}
   */
  get delta () {
@@ -149,11 +162,19 @@ export class YEvent {
  }

  /**
+   * This is a computed property. Note that this can only be safely computed during the
+   * event call. Computing this property after other changes happened might result in
+   * unexpected behavior (incorrect computation of deltas). A safe way to collect changes
+   * is to store the `changes` or the `delta` object. Avoid storing the `transaction` object.
+   *
   * @type {{added:Set<Item>,deleted:Set<Item>,keys:Map<string,{action:'add'|'update'|'delete',oldValue:any}>,delta:Array<{insert?:Array<any>|string, delete?:number, retain?:number}>}}
   */
  get changes () {
    let changes = this._changes
    if (changes === null) {
+      if (this.transaction.doc._transactionCleanups.length === 0) {
+        throw error.create(errorComputeChanges)
+      }
      const target = this.target
      const added = set.create()
      const deleted = set.create()
--- a/src/utils/encoding.js
+++ b/src/utils/encoding.js
@@ -1,4 +1,3 @@
-
 /**
 * @module encoding
 */
@@ -45,6 +44,7 @@ import * as decoding from 'lib0/decoding'
 import * as binary from 'lib0/binary'
 import * as map from 'lib0/map'
 import * as math from 'lib0/math'
+import * as array from 'lib0/array'

 /**
 * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
@@ -87,7 +87,7 @@ export const writeClientsStructs = (encoder, store, _sm) => {
      sm.set(client, clock)
    }
  })
-  getStateVector(store).forEach((clock, client) => {
+  getStateVector(store).forEach((_clock, client) => {
    if (!_sm.has(client)) {
      sm.set(client, 0)
    }
@@ -96,9 +96,8 @@ export const writeClientsStructs = (encoder, store, _sm) => {
  encoding.writeVarUint(encoder.restEncoder, sm.size)
  // Write items with higher client ids first
  // This heavily improves the conflict algorithm.
-  Array.from(sm.entries()).sort((a, b) => b[0] - a[0]).forEach(([client, clock]) => {
-    // @ts-ignore
-    writeStructs(encoder, store.clients.get(client), client, clock)
+  array.from(sm.entries()).sort((a, b) => b[0] - a[0]).forEach(([client, clock]) => {
+    writeStructs(encoder, /** @type {Array<GC|Item>} */ (store.clients.get(client)), client, clock)
  })
 }

@@ -231,7 +230,7 @@ const integrateStructs = (transaction, store, clientsStructRefs) => {
   */
  const stack = []
  // sort them so that we take the higher id first, in case of conflicts the lower id will probably not conflict with the id from the higher user.
-  let clientsStructRefsIds = Array.from(clientsStructRefs.keys()).sort((a, b) => a - b)
+  let clientsStructRefsIds = array.from(clientsStructRefs.keys()).sort((a, b) => a - b)
  if (clientsStructRefsIds.length === 0) {
    return null
  }
@@ -251,7 +250,7 @@ const integrateStructs = (transaction, store, clientsStructRefs) => {
    return nextStructsTarget
  }
  let curStructsTarget = getNextStructTarget()
-  if (curStructsTarget === null && stack.length === 0) {
+  if (curStructsTarget === null) {
    return null
  }

@@ -601,7 +600,7 @@ export const decodeStateVector = decodedState => readStateVector(new DSDecoderV1
 */
 export const writeStateVector = (encoder, sv) => {
  encoding.writeVarUint(encoder.restEncoder, sv.size)
-  Array.from(sv.entries()).sort((a, b) => b[0] - a[0]).forEach(([client, clock]) => {
+  array.from(sv.entries()).sort((a, b) => b[0] - a[0]).forEach(([client, clock]) => {
    encoding.writeVarUint(encoder.restEncoder, client) // @todo use a special client decoder that is based on mapping
    encoding.writeVarUint(encoder.restEncoder, clock)
  })
--- a/src/utils/isParentOf.js
+++ b/src/utils/isParentOf.js
@@ -1,4 +1,3 @@
-
 import { AbstractType, Item } from '../internals.js' // eslint-disable-line

 /**
--- a/src/utils/logging.js
+++ b/src/utils/logging.js
@@ -1,4 +1,3 @@
-
 import {
  AbstractType // eslint-disable-line
 } from '../internals.js'
--- a/src/utils/updates.js
+++ b/src/utils/updates.js
@@ -1,20 +1,40 @@
-
 import * as binary from 'lib0/binary'
 import * as decoding from 'lib0/decoding'
 import * as encoding from 'lib0/encoding'
+import * as error from 'lib0/error'
+import * as f from 'lib0/function'
 import * as logging from 'lib0/logging'
+import * as map from 'lib0/map'
 import * as math from 'lib0/math'
+import * as string from 'lib0/string'
+
 import {
+  ContentAny,
+  ContentBinary,
+  ContentDeleted,
+  ContentDoc,
+  ContentEmbed,
+  ContentFormat,
+  ContentJSON,
+  ContentString,
+  ContentType,
  createID,
-  readItemContent,
-  readDeleteSet,
-  writeDeleteSet,
-  Skip,
-  mergeDeleteSets,
+  decodeStateVector,
  DSEncoderV1,
  DSEncoderV2,
-  decodeStateVector,
-  Item, GC, UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2 // eslint-disable-line
+  GC,
+  Item,
+  mergeDeleteSets,
+  readDeleteSet,
+  readItemContent,
+  Skip,
+  UpdateDecoderV1,
+  UpdateDecoderV2,
+  UpdateEncoderV1,
+  UpdateEncoderV2,
+  writeDeleteSet,
+  YXmlElement,
+  YXmlHook
 } from '../internals.js'

 /**
@@ -552,17 +572,17 @@ const finishLazyStructWriting = (lazyWriter) => {

 /**
 * @param {Uint8Array} update
+ * @param {function(Item|GC|Skip):Item|GC|Skip} blockTransformer
 * @param {typeof UpdateDecoderV2 | typeof UpdateDecoderV1} YDecoder
 * @param {typeof UpdateEncoderV2 | typeof UpdateEncoderV1 } YEncoder
 */
-export const convertUpdateFormat = (update, YDecoder, YEncoder) => {
+export const convertUpdateFormat = (update, blockTransformer, YDecoder, YEncoder) => {
  const updateDecoder = new YDecoder(decoding.createDecoder(update))
  const lazyDecoder = new LazyStructReader(updateDecoder, false)
  const updateEncoder = new YEncoder()
  const lazyWriter = new LazyStructWriter(updateEncoder)
-
  for (let curr = lazyDecoder.curr; curr !== null; curr = lazyDecoder.next()) {
-    writeStructToLazyStructWriter(lazyWriter, curr, 0)
+    writeStructToLazyStructWriter(lazyWriter, blockTransformer(curr), 0)
  }
  finishLazyStructWriting(lazyWriter)
  const ds = readDeleteSet(updateDecoder)
@@ -571,11 +591,132 @@ export const convertUpdateFormat = (update, YDecoder, YEncoder) => {
 }

 /**
- * @param {Uint8Array} update
+ * @typedef {Object} ObfuscatorOptions
+ * @property {boolean} [ObfuscatorOptions.formatting=true]
+ * @property {boolean} [ObfuscatorOptions.subdocs=true]
+ * @property {boolean} [ObfuscatorOptions.yxml=true] Whether to obfuscate nodeName / hookName
 */
-export const convertUpdateFormatV1ToV2 = update => convertUpdateFormat(update, UpdateDecoderV1, UpdateEncoderV2)
+
+/**
+ * @param {ObfuscatorOptions} obfuscator
+ */
+const createObfuscator = ({ formatting = true, subdocs = true, yxml = true } = {}) => {
+  let i = 0
+  const mapKeyCache = map.create()
+  const nodeNameCache = map.create()
+  const formattingKeyCache = map.create()
+  const formattingValueCache = map.create()
+  formattingValueCache.set(null, null) // end of a formatting range should always be the end of a formatting range
+  /**
+   * @param {Item|GC|Skip} block
+   * @return {Item|GC|Skip}
+   */
+  return block => {
+    switch (block.constructor) {
+      case GC:
+      case Skip:
+        return block
+      case Item: {
+        const item = /** @type {Item} */ (block)
+        const content = item.content
+        switch (content.constructor) {
+          case ContentDeleted:
+            break
+          case ContentType: {
+            if (yxml) {
+              const type = /** @type {ContentType} */ (content).type
+              if (type instanceof YXmlElement) {
+                type.nodeName = map.setIfUndefined(nodeNameCache, type.nodeName, () => 'node-' + i)
+              }
+              if (type instanceof YXmlHook) {
+                type.hookName = map.setIfUndefined(nodeNameCache, type.hookName, () => 'hook-' + i)
+              }
+            }
+            break
+          }
+          case ContentAny: {
+            const c = /** @type {ContentAny} */ (content)
+            c.arr = c.arr.map(() => i)
+            break
+          }
+          case ContentBinary: {
+            const c = /** @type {ContentBinary} */ (content)
+            c.content = new Uint8Array([i])
+            break
+          }
+          case ContentDoc: {
+            const c = /** @type {ContentDoc} */ (content)
+            if (subdocs) {
+              c.opts = {}
+              c.doc.guid = i + ''
+            }
+            break
+          }
+          case ContentEmbed: {
+            const c = /** @type {ContentEmbed} */ (content)
+            c.embed = {}
+            break
+          }
+          case ContentFormat: {
+            const c = /** @type {ContentFormat} */ (content)
+            if (formatting) {
+              c.key = map.setIfUndefined(formattingKeyCache, c.key, () => i + '')
+              c.value = map.setIfUndefined(formattingValueCache, c.value, () => ({ i }))
+            }
+            break
+          }
+          case ContentJSON: {
+            const c = /** @type {ContentJSON} */ (content)
+            c.arr = c.arr.map(() => i)
+            break
+          }
+          case ContentString: {
+            const c = /** @type {ContentString} */ (content)
+            c.str = string.repeat((i % 10) + '', c.str.length)
+            break
+          }
+          default:
+            // unknown content type
+            error.unexpectedCase()
+        }
+        if (item.parentSub) {
+          item.parentSub = map.setIfUndefined(mapKeyCache, item.parentSub, () => i + '')
+        }
+        i++
+        return block
+      }
+      default:
+        // unknown block-type
+        error.unexpectedCase()
+    }
+  }
+}
+
+/**
+ * This function obfuscates the content of a Yjs update. This is useful to share
+ * buggy Yjs documents while significantly limiting the possibility that a
+ * developer can on the user. Note that it might still be possible to deduce
+ * some information by analyzing the "structure" of the document or by analyzing
+ * the typing behavior using the CRDT-related metadata that is still kept fully
+ * intact.
+ *
+ * @param {Uint8Array} update
+ * @param {ObfuscatorOptions} [opts]
+ */
+export const obfuscateUpdate = (update, opts) => convertUpdateFormat(update, createObfuscator(opts), UpdateDecoderV1, UpdateEncoderV1)
+
+/**
+ * @param {Uint8Array} update
+ * @param {ObfuscatorOptions} [opts]
+ */
+export const obfuscateUpdateV2 = (update, opts) => convertUpdateFormat(update, createObfuscator(opts), UpdateDecoderV2, UpdateEncoderV2)

 /**
 * @param {Uint8Array} update
 */
-export const convertUpdateFormatV2ToV1 = update => convertUpdateFormat(update, UpdateDecoderV2, UpdateEncoderV1)
+export const convertUpdateFormatV1ToV2 = update => convertUpdateFormat(update, f.id, UpdateDecoderV1, UpdateEncoderV2)
+
+/**
+ * @param {Uint8Array} update
+ */
+export const convertUpdateFormatV2ToV1 = update => convertUpdateFormat(update, f.id, UpdateDecoderV2, UpdateEncoderV1)
--- a/tests/compatibility.tests.js
+++ b/tests/compatibility.tests.js
@@ -1,4 +1,3 @@
-
 /**
 * Testing if encoding/decoding compatibility and integration compatiblity is given.
 * We expect that the document always looks the same, even if we upgrade the integration algorithm, or add additional encoding approaches.
--- a/tests/doc.tests.js
+++ b/tests/doc.tests.js
@@ -1,13 +1,55 @@
-
 import * as Y from '../src/index.js'
 import * as t from 'lib0/testing'

+/**
+ * @param {t.TestCase} _tc
+ */
+export const testAfterTransactionRecursion = _tc => {
+  const ydoc = new Y.Doc()
+  const yxml = ydoc.getXmlFragment('')
+  ydoc.on('afterTransaction', tr => {
+    if (tr.origin === 'test') {
+      yxml.toJSON()
+    }
+  })
+  ydoc.transact(_tr => {
+    for (let i = 0; i < 15000; i++) {
+      yxml.push([new Y.XmlText('a')])
+    }
+  }, 'test')
+}
+
+/**
+ * @param {t.TestCase} _tc
+ */
+export const testOriginInTransaction = _tc => {
+  const doc = new Y.Doc()
+  const ytext = doc.getText()
+  /**
+   * @type {Array<string>}
+   */
+  const origins = []
+  doc.on('afterTransaction', (tr) => {
+    origins.push(tr.origin)
+    if (origins.length <= 1) {
+      ytext.toDelta(Y.snapshot(doc)) // adding a snapshot forces toDelta to create a cleanup transaction
+      doc.transact(() => {
+        ytext.insert(0, 'a')
+      }, 'nested')
+    }
+  })
+  doc.transact(() => {
+    ytext.insert(0, '0')
+  }, 'first')
+  t.compareArrays(origins, ['first', 'cleanup', 'nested'])
+}
+
 /**
 * Client id should be changed when an instance receives updates from another client using the same client id.
 *
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testClientIdDuplicateChange = tc => {
+export const testClientIdDuplicateChange = _tc => {
  const doc1 = new Y.Doc()
  doc1.clientID = 0
  const doc2 = new Y.Doc()
@@ -19,9 +61,9 @@ export const testClientIdDuplicateChange = tc => {
 }

 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testGetTypeEmptyId = tc => {
+export const testGetTypeEmptyId = _tc => {
  const doc1 = new Y.Doc()
  doc1.getText('').insert(0, 'h')
  doc1.getText().insert(1, 'i')
@@ -32,9 +74,9 @@ export const testGetTypeEmptyId = tc => {
 }

 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testToJSON = tc => {
+export const testToJSON = _tc => {
  const doc = new Y.Doc()
  t.compare(doc.toJSON(), {}, 'doc.toJSON yields empty object')

@@ -59,9 +101,9 @@ export const testToJSON = tc => {
 }

 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testSubdoc = tc => {
+export const testSubdoc = _tc => {
  const doc = new Y.Doc()
  doc.load() // doesn't do anything
  {
@@ -126,9 +168,9 @@ export const testSubdoc = tc => {
 }

 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testSubdocLoadEdgeCases = tc => {
+export const testSubdocLoadEdgeCases = _tc => {
  const ydoc = new Y.Doc()
  const yarray = ydoc.getArray()
  const subdoc1 = new Y.Doc()
@@ -173,9 +215,9 @@ export const testSubdocLoadEdgeCases = tc => {
 }

 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testSubdocLoadEdgeCasesAutoload = tc => {
+export const testSubdocLoadEdgeCasesAutoload = _tc => {
  const ydoc = new Y.Doc()
  const yarray = ydoc.getArray()
  const subdoc1 = new Y.Doc({ autoLoad: true })
@@ -215,9 +257,9 @@ export const testSubdocLoadEdgeCasesAutoload = tc => {
 }

 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testSubdocsUndo = tc => {
+export const testSubdocsUndo = _tc => {
  const ydoc = new Y.Doc()
  const elems = ydoc.getXmlFragment()
  const undoManager = new Y.UndoManager(elems)
@@ -230,9 +272,9 @@ export const testSubdocsUndo = tc => {
 }

 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testLoadDocs = async tc => {
+export const testLoadDocsEvent = async _tc => {
  const ydoc = new Y.Doc()
  t.assert(ydoc.isLoaded === false)
  let loadedEvent = false
@@ -244,3 +286,44 @@ export const testLoadDocs = async tc => {
  t.assert(loadedEvent)
  t.assert(ydoc.isLoaded)
 }
+
+/**
+ * @param {t.TestCase} _tc
+ */
+export const testSyncDocsEvent = async _tc => {
+  const ydoc = new Y.Doc()
+  t.assert(ydoc.isLoaded === false)
+  t.assert(ydoc.isSynced === false)
+  let loadedEvent = false
+  ydoc.once('load', () => {
+    loadedEvent = true
+  })
+  let syncedEvent = false
+  ydoc.once('sync', /** @param {any} isSynced */ (isSynced) => {
+    syncedEvent = true
+    t.assert(isSynced)
+  })
+  ydoc.emit('sync', [true, ydoc])
+  await ydoc.whenLoaded
+  const oldWhenSynced = ydoc.whenSynced
+  await ydoc.whenSynced
+  t.assert(loadedEvent)
+  t.assert(syncedEvent)
+  t.assert(ydoc.isLoaded)
+  t.assert(ydoc.isSynced)
+  let loadedEvent2 = false
+  ydoc.on('load', () => {
+    loadedEvent2 = true
+  })
+  let syncedEvent2 = false
+  ydoc.on('sync', (isSynced) => {
+    syncedEvent2 = true
+    t.assert(isSynced === false)
+  })
+  ydoc.emit('sync', [false, ydoc])
+  t.assert(!loadedEvent2)
+  t.assert(syncedEvent2)
+  t.assert(ydoc.isLoaded)
+  t.assert(!ydoc.isSynced)
+  t.assert(ydoc.whenSynced !== oldWhenSynced)
+}
--- a/tests/index.js
+++ b/tests/index.js
@@ -1,3 +1,4 @@
+/* eslint-env node */

 import * as map from './y-map.tests.js'
 import * as array from './y-array.tests.js'
--- a/tests/relativePositions.tests.js
+++ b/tests/relativePositions.tests.js
@@ -1,4 +1,3 @@
-
 import * as Y from '../src/index.js'
 import * as t from 'lib0/testing'

--- a/tests/snapshot.tests.js
+++ b/tests/snapshot.tests.js
@@ -3,9 +3,36 @@ import * as t from 'lib0/testing'
 import { init } from './testHelper.js'

 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testBasicRestoreSnapshot = tc => {
+export const testBasic = _tc => {
+  const ydoc = new Y.Doc({ gc: false })
+  ydoc.getText().insert(0, 'world!')
+  const snapshot = Y.snapshot(ydoc)
+  ydoc.getText().insert(0, 'hello ')
+  const restored = Y.createDocFromSnapshot(ydoc, snapshot)
+  t.assert(restored.getText().toString() === 'world!')
+}
+
+/**
+ * @param {t.TestCase} _tc
+ */
+export const testBasicXmlAttributes = _tc => {
+  const ydoc = new Y.Doc({ gc: false })
+  const yxml = ydoc.getMap().set('el', new Y.XmlElement('div'))
+  const snapshot1 = Y.snapshot(ydoc)
+  yxml.setAttribute('a', '1')
+  const snapshot2 = Y.snapshot(ydoc)
+  yxml.setAttribute('a', '2')
+  t.compare(yxml.getAttributes(), { a: '2' })
+  t.compare(yxml.getAttributes(snapshot2), { a: '1' })
+  t.compare(yxml.getAttributes(snapshot1), {})
+}
+
+/**
+ * @param {t.TestCase} _tc
+ */
+export const testBasicRestoreSnapshot = _tc => {
  const doc = new Y.Doc({ gc: false })
  doc.getArray('array').insert(0, ['hello'])
  const snap = Y.snapshot(doc)
@@ -18,9 +45,9 @@ export const testBasicRestoreSnapshot = tc => {
 }

 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testEmptyRestoreSnapshot = tc => {
+export const testEmptyRestoreSnapshot = _tc => {
  const doc = new Y.Doc({ gc: false })
  const snap = Y.snapshot(doc)
  snap.sv.set(9999, 0)
@@ -38,9 +65,9 @@ export const testEmptyRestoreSnapshot = tc => {
 }

 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testRestoreSnapshotWithSubType = tc => {
+export const testRestoreSnapshotWithSubType = _tc => {
  const doc = new Y.Doc({ gc: false })
  doc.getArray('array').insert(0, [new Y.Map()])
  const subMap = doc.getArray('array').get(0)
@@ -61,9 +88,9 @@ export const testRestoreSnapshotWithSubType = tc => {
 }

 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testRestoreDeletedItem1 = tc => {
+export const testRestoreDeletedItem1 = _tc => {
  const doc = new Y.Doc({ gc: false })
  doc.getArray('array').insert(0, ['item1', 'item2'])

@@ -77,9 +104,9 @@ export const testRestoreDeletedItem1 = tc => {
 }

 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testRestoreLeftItem = tc => {
+export const testRestoreLeftItem = _tc => {
  const doc = new Y.Doc({ gc: false })
  doc.getArray('array').insert(0, ['item1'])
  doc.getMap('map').set('test', 1)
@@ -95,9 +122,9 @@ export const testRestoreLeftItem = tc => {
 }

 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testDeletedItemsBase = tc => {
+export const testDeletedItemsBase = _tc => {
  const doc = new Y.Doc({ gc: false })
  doc.getArray('array').insert(0, ['item1'])
  doc.getArray('array').delete(0)
@@ -111,9 +138,9 @@ export const testDeletedItemsBase = tc => {
 }

 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testDeletedItems2 = tc => {
+export const testDeletedItems2 = _tc => {
  const doc = new Y.Doc({ gc: false })
  doc.getArray('array').insert(0, ['item1', 'item2', 'item3'])
  doc.getArray('array').delete(1)
@@ -169,3 +196,28 @@ export const testDependentChanges = tc => {
  const docRestored1 = Y.createDocFromSnapshot(array1.doc, snap)
  t.compare(docRestored1.getArray('array').toArray(), ['user1item1', 'user2item1'])
 }
+
+/**
+ * @param {t.TestCase} _tc
+ */
+export const testContainsUpdate = _tc => {
+  const ydoc = new Y.Doc()
+  /**
+   * @type {Array<Uint8Array>}
+   */
+  const updates = []
+  ydoc.on('update', update => {
+    updates.push(update)
+  })
+  const yarr = ydoc.getArray()
+  const snapshot1 = Y.snapshot(ydoc)
+  yarr.insert(0, [1])
+  const snapshot2 = Y.snapshot(ydoc)
+  yarr.delete(0, 1)
+  const snapshotFinal = Y.snapshot(ydoc)
+  t.assert(!Y.snapshotContainsUpdate(snapshot1, updates[0]))
+  t.assert(!Y.snapshotContainsUpdate(snapshot2, updates[1]))
+  t.assert(Y.snapshotContainsUpdate(snapshot2, updates[0]))
+  t.assert(Y.snapshotContainsUpdate(snapshotFinal, updates[0]))
+  t.assert(Y.snapshotContainsUpdate(snapshotFinal, updates[1]))
+}
--- a/tests/testHelper.js
+++ b/tests/testHelper.js
@@ -1,4 +1,3 @@
-
 import * as t from 'lib0/testing'
 import * as prng from 'lib0/prng'
 import * as encoding from 'lib0/encoding'
@@ -134,7 +133,7 @@ export class TestYInstance extends Y.Doc {
   * @param {TestYInstance} remoteClient
   */
  _receive (message, remoteClient) {
-    map.setIfUndefined(this.receiving, remoteClient, () => []).push(message)
+    map.setIfUndefined(this.receiving, remoteClient, () => /** @type {Array<Uint8Array>} */ ([])).push(message)
  }
 }

@@ -347,7 +346,7 @@ export const compare = users => {
    t.compare(userMapValues[i], userMapValues[i + 1])
    t.compare(userXmlValues[i], userXmlValues[i + 1])
    t.compare(userTextValues[i].map(/** @param {any} a */ a => typeof a.insert === 'string' ? a.insert : ' ').join('').length, users[i].getText('text').length)
-    t.compare(userTextValues[i], userTextValues[i + 1], '', (constructor, a, b) => {
+    t.compare(userTextValues[i], userTextValues[i + 1], '', (_constructor, a, b) => {
      if (a instanceof Y.AbstractType) {
        t.compare(a.toJSON(), b.toJSON())
      } else if (a !== b) {
@@ -356,8 +355,9 @@ export const compare = users => {
      return true
    })
    t.compare(Y.encodeStateVector(users[i]), Y.encodeStateVector(users[i + 1]))
-    compareDS(Y.createDeleteSetFromStructStore(users[i].store), Y.createDeleteSetFromStructStore(users[i + 1].store))
+    Y.equalDeleteSets(Y.createDeleteSetFromStructStore(users[i].store), Y.createDeleteSetFromStructStore(users[i + 1].store))
    compareStructStores(users[i].store, users[i + 1].store)
+    t.compare(Y.encodeSnapshot(Y.snapshot(users[i])), Y.encodeSnapshot(Y.snapshot(users[i + 1])))
  }
  users.map(u => u.destroy())
 }
@@ -370,8 +370,8 @@ export const compare = users => {
 export const compareItemIDs = (a, b) => a === b || (a !== null && b != null && Y.compareIDs(a.id, b.id))

 /**
- * @param {import('../src/internals').StructStore} ss1
- * @param {import('../src/internals').StructStore} ss2
+ * @param {import('../src/internals.js').StructStore} ss1
+ * @param {import('../src/internals.js').StructStore} ss2
 */
 export const compareStructStores = (ss1, ss2) => {
  t.assert(ss1.clients.size === ss2.clients.size)
@@ -412,25 +412,6 @@ export const compareStructStores = (ss1, ss2) => {
  }
 }

-/**
- * @param {import('../src/internals').DeleteSet} ds1
- * @param {import('../src/internals').DeleteSet} ds2
- */
-export const compareDS = (ds1, ds2) => {
-  t.assert(ds1.clients.size === ds2.clients.size)
-  ds1.clients.forEach((deleteItems1, client) => {
-    const deleteItems2 = /** @type {Array<import('../src/internals').DeleteItem>} */ (ds2.clients.get(client))
-    t.assert(deleteItems2 !== undefined && deleteItems1.length === deleteItems2.length)
-    for (let i = 0; i < deleteItems1.length; i++) {
-      const di1 = deleteItems1[i]
-      const di2 = deleteItems2[i]
-      if (di1.clock !== di2.clock || di1.len !== di2.len) {
-        t.fail('DeleteSets dont match')
-      }
-    }
-  })
-}
-
 /**
 * @template T
 * @callback InitTestObjectCallback
--- a/tests/undo-redo.tests.js
+++ b/tests/undo-redo.tests.js
@@ -1,8 +1,61 @@
-import { init, compare, applyRandomTests, Doc } from './testHelper.js' // eslint-disable-line
+import { init } from './testHelper.js' // eslint-disable-line

 import * as Y from '../src/index.js'
 import * as t from 'lib0/testing'

+export const testInconsistentFormat = () => {
+  /**
+   * @param {Y.Doc} ydoc
+   */
+  const testYjsMerge = ydoc => {
+    const content = /** @type {Y.XmlText} */ (ydoc.get('text', Y.XmlText))
+    content.format(0, 6, { bold: null })
+    content.format(6, 4, { type: 'text' })
+    t.compare(content.toDelta(), [
+      {
+        attributes: { type: 'text' },
+        insert: 'Merge Test'
+      },
+      {
+        attributes: { type: 'text', italic: true },
+        insert: ' After'
+      }
+    ])
+  }
+  const initializeYDoc = () => {
+    const yDoc = new Y.Doc({ gc: false })
+
+    const content = /** @type {Y.XmlText} */ (yDoc.get('text', Y.XmlText))
+    content.insert(0, ' After', { type: 'text', italic: true })
+    content.insert(0, 'Test', { type: 'text' })
+    content.insert(0, 'Merge ', { type: 'text', bold: true })
+    return yDoc
+  }
+  {
+    const yDoc = initializeYDoc()
+    testYjsMerge(yDoc)
+  }
+  {
+    const initialYDoc = initializeYDoc()
+    const yDoc = new Y.Doc({ gc: false })
+    Y.applyUpdate(yDoc, Y.encodeStateAsUpdate(initialYDoc))
+    testYjsMerge(yDoc)
+  }
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testInfiniteCaptureTimeout = tc => {
+  const { array0 } = init(tc, { users: 3 })
+  const undoManager = new Y.UndoManager(array0, { captureTimeout: Number.MAX_VALUE })
+  array0.push([1, 2, 3])
+  undoManager.stopCapturing()
+  array0.push([4, 5, 6])
+  undoManager.undo()
+  t.compare(array0.toArray(), [1, 2, 3])
+}
+
 /**
 * @param {t.TestCase} tc
 */
@@ -51,9 +104,23 @@ export const testUndoText = tc => {

 /**
 * Test case to fix #241
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testDoubleUndo = tc => {
+export const testEmptyTypeScope = _tc => {
+  const ydoc = new Y.Doc()
+  const um = new Y.UndoManager([], { doc: ydoc })
+  const yarray = ydoc.getArray()
+  um.addToScope(yarray)
+  yarray.insert(0, [1])
+  um.undo()
+  t.assert(yarray.length === 0)
+}
+
+/**
+ * Test case to fix #241
+ * @param {t.TestCase} _tc
+ */
+export const testDoubleUndo = _tc => {
  const doc = new Y.Doc()
  const text = doc.getText()
  text.insert(0, '1221')
@@ -289,9 +356,9 @@ export const testUndoDeleteFilter = tc => {

 /**
 * This issue has been reported in https://discuss.yjs.dev/t/undomanager-with-external-updates/454/6
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testUndoUntilChangePerformed = tc => {
+export const testUndoUntilChangePerformed = _tc => {
  const doc = new Y.Doc()
  const doc2 = new Y.Doc()
  doc.on('update', update => Y.applyUpdate(doc2, update))
@@ -320,9 +387,9 @@ export const testUndoUntilChangePerformed = tc => {

 /**
 * This issue has been reported in https://github.com/yjs/yjs/issues/317
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testUndoNestedUndoIssue = tc => {
+export const testUndoNestedUndoIssue = _tc => {
  const doc = new Y.Doc({ gc: false })
  const design = doc.getMap()
  const undoManager = new Y.UndoManager(design, { captureTimeout: 0 })
@@ -376,9 +443,9 @@ export const testUndoNestedUndoIssue = tc => {
 /**
 * This issue has been reported in https://github.com/yjs/yjs/issues/355
 *
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testConsecutiveRedoBug = tc => {
+export const testConsecutiveRedoBug = _tc => {
  const doc = new Y.Doc()
  const yRoot = doc.getMap()
  const undoMgr = new Y.UndoManager(yRoot)
@@ -427,9 +494,9 @@ export const testConsecutiveRedoBug = tc => {
 /**
 * This issue has been reported in https://github.com/yjs/yjs/issues/304
 *
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testUndoXmlBug = tc => {
+export const testUndoXmlBug = _tc => {
  const origin = 'origin'
  const doc = new Y.Doc()
  const fragment = doc.getXmlFragment('t')
@@ -472,9 +539,9 @@ export const testUndoXmlBug = tc => {
 /**
 * This issue has been reported in https://github.com/yjs/yjs/issues/343
 *
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testUndoBlockBug = tc => {
+export const testUndoBlockBug = _tc => {
  const doc = new Y.Doc({ gc: false })
  const design = doc.getMap()

@@ -532,9 +599,9 @@ export const testUndoBlockBug = tc => {
 * Undo text formatting delete should not corrupt peer state.
 *
 * @see https://github.com/yjs/yjs/issues/392
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testUndoDeleteTextFormat = tc => {
+export const testUndoDeleteTextFormat = _tc => {
  const doc = new Y.Doc()
  const text = doc.getText()
  text.insert(0, 'Attack ships on fire off the shoulder of Orion.')
@@ -570,9 +637,9 @@ export const testUndoDeleteTextFormat = tc => {
 * Undo text formatting delete should not corrupt peer state.
 *
 * @see https://github.com/yjs/yjs/issues/392
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testBehaviorOfIgnoreremotemapchangesProperty = tc => {
+export const testBehaviorOfIgnoreremotemapchangesProperty = _tc => {
  const doc = new Y.Doc()
  const doc2 = new Y.Doc()
  doc.on('update', update => Y.applyUpdate(doc2, update, doc))
@@ -588,3 +655,63 @@ export const testBehaviorOfIgnoreremotemapchangesProperty = tc => {
  t.assert(map1.get('x') === 2)
  t.assert(map2.get('x') === 2)
 }
+
+/**
+ * Special deletion case.
+ *
+ * @see https://github.com/yjs/yjs/issues/447
+ * @param {t.TestCase} _tc
+ */
+export const testSpecialDeletionCase = _tc => {
+  const origin = 'undoable'
+  const doc = new Y.Doc()
+  const fragment = doc.getXmlFragment()
+  const undoManager = new Y.UndoManager(fragment, { trackedOrigins: new Set([origin]) })
+  doc.transact(() => {
+    const e = new Y.XmlElement('test')
+    e.setAttribute('a', '1')
+    e.setAttribute('b', '2')
+    fragment.insert(0, [e])
+  })
+  t.compareStrings(fragment.toString(), '<test a="1" b="2"></test>')
+  doc.transact(() => {
+    // change attribute "b" and delete test-node
+    const e = fragment.get(0)
+    e.setAttribute('b', '3')
+    fragment.delete(0)
+  }, origin)
+  t.compareStrings(fragment.toString(), '')
+  undoManager.undo()
+  t.compareStrings(fragment.toString(), '<test a="1" b="2"></test>')
+}
+
+/**
+ * Deleted entries in a map should be restored on undo.
+ *
+ * @see https://github.com/yjs/yjs/issues/500
+ * @param {t.TestCase} tc
+ */
+export const testUndoDeleteInMap = (tc) => {
+  const { map0 } = init(tc, { users: 3 })
+  const undoManager = new Y.UndoManager(map0, { captureTimeout: 0 })
+  map0.set('a', 'a')
+  map0.delete('a')
+  map0.set('a', 'b')
+  map0.delete('a')
+  map0.set('a', 'c')
+  map0.delete('a')
+  map0.set('a', 'd')
+  t.compare(map0.toJSON(), { a: 'd' })
+  undoManager.undo()
+  t.compare(map0.toJSON(), {})
+  undoManager.undo()
+  t.compare(map0.toJSON(), { a: 'c' })
+  undoManager.undo()
+  t.compare(map0.toJSON(), {})
+  undoManager.undo()
+  t.compare(map0.toJSON(), { a: 'b' })
+  undoManager.undo()
+  t.compare(map0.toJSON(), {})
+  undoManager.undo()
+  t.compare(map0.toJSON(), { a: 'a' })
+}
--- a/tests/updates.tests.js
+++ b/tests/updates.tests.js
@@ -4,6 +4,7 @@ import * as Y from '../src/index.js'
 import { readClientsStructRefs, readDeleteSet, UpdateDecoderV2, UpdateEncoderV2, writeDeleteSet } from '../src/internals.js'
 import * as encoding from 'lib0/encoding'
 import * as decoding from 'lib0/decoding'
+import * as object from 'lib0/object'

 /**
 * @typedef {Object} Enc
@@ -138,7 +139,6 @@ export const testKeyEncoding = tc => {
 */
 const checkUpdateCases = (ydoc, updates, enc, hasDeletes) => {
  const cases = []
-
  // Case 1: Simple case, simply merge everything
  cases.push(enc.mergeUpdates(updates))

@@ -304,3 +304,54 @@ export const testMergePendingUpdates = tc => {
  const yText5 = yDoc5.getText('textBlock')
  t.compareStrings(yText5.toString(), 'nenor')
 }
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testObfuscateUpdates = tc => {
+  const ydoc = new Y.Doc()
+  const ytext = ydoc.getText('text')
+  const ymap = ydoc.getMap('map')
+  const yarray = ydoc.getArray('array')
+  // test ytext
+  ytext.applyDelta([{ insert: 'text', attributes: { bold: true } }, { insert: { href: 'supersecreturl' } }])
+  // test ymap
+  ymap.set('key', 'secret1')
+  ymap.set('key', 'secret2')
+  // test yarray with subtype & subdoc
+  const subtype = new Y.XmlElement('secretnodename')
+  const subdoc = new Y.Doc({ guid: 'secret' })
+  subtype.setAttribute('attr', 'val')
+  yarray.insert(0, ['teststring', 42, subtype, subdoc])
+  // obfuscate the content and put it into a new document
+  const obfuscatedUpdate = Y.obfuscateUpdate(Y.encodeStateAsUpdate(ydoc))
+  const odoc = new Y.Doc()
+  Y.applyUpdate(odoc, obfuscatedUpdate)
+  const otext = odoc.getText('text')
+  const omap = odoc.getMap('map')
+  const oarray = odoc.getArray('array')
+  // test ytext
+  const delta = otext.toDelta()
+  t.assert(delta.length === 2)
+  t.assert(delta[0].insert !== 'text' && delta[0].insert.length === 4)
+  t.assert(object.length(delta[0].attributes) === 1)
+  t.assert(!object.hasProperty(delta[0].attributes, 'bold'))
+  t.assert(object.length(delta[1]) === 1)
+  t.assert(object.hasProperty(delta[1], 'insert'))
+  // test ymap
+  t.assert(omap.size === 1)
+  t.assert(!omap.has('key'))
+  // test yarray with subtype & subdoc
+  const result = oarray.toArray()
+  t.assert(result.length === 4)
+  t.assert(result[0] !== 'teststring')
+  t.assert(result[1] !== 42)
+  const osubtype = /** @type {Y.XmlElement} */ (result[2])
+  const osubdoc = result[3]
+  // test subtype
+  t.assert(osubtype.nodeName !== subtype.nodeName)
+  t.assert(object.length(osubtype.getAttributes()) === 1)
+  t.assert(osubtype.getAttribute('attr') === undefined)
+  // test subdoc
+  t.assert(osubdoc.guid !== subdoc.guid)
+}
--- a/tests/y-array.tests.js
+++ b/tests/y-array.tests.js
@@ -32,6 +32,17 @@ export const testSlice = tc => {
  t.compareArrays(arr.slice(0, 2), [0, 1])
 }

+/**
+ * @param {t.TestCase} tc
+ */
+export const testArrayFrom = tc => {
+  const doc1 = new Y.Doc()
+  const db1 = doc1.getMap('root')
+  const nestedArray1 = Y.Array.from([0, 1, 2])
+  db1.set('array', nestedArray1)
+  t.compare(nestedArray1.toArray(), [0, 1, 2])
+}
+
 /**
 * Debugging yjs#297 - a critical bug connected to the search-marker approach
 *
--- a/tests/y-map.tests.js
+++ b/tests/y-map.tests.js
@@ -8,6 +8,54 @@ import * as Y from '../src/index.js'
 import * as t from 'lib0/testing'
 import * as prng from 'lib0/prng'

+/**
+ * @param {t.TestCase} _tc
+ */
+export const testIterators = _tc => {
+  const ydoc = new Y.Doc()
+  /**
+   * @type {Y.Map<number>}
+   */
+  const ymap = ydoc.getMap()
+  // we are only checking if the type assumptions are correct
+  /**
+   * @type {Array<number>}
+   */
+  const vals = Array.from(ymap.values())
+  /**
+   * @type {Array<[string,number]>}
+   */
+  const entries = Array.from(ymap.entries())
+  /**
+   * @type {Array<string>}
+   */
+  const keys = Array.from(ymap.keys())
+  console.log(vals, entries, keys)
+}
+
+/**
+ * Computing event changes after transaction should result in an error. See yjs#539
+ *
+ * @param {t.TestCase} _tc
+ */
+export const testMapEventError = _tc => {
+  const doc = new Y.Doc()
+  const ymap = doc.getMap()
+  /**
+   * @type {any}
+   */
+  let event = null
+  ymap.observe((e) => {
+    event = e
+  })
+  t.fails(() => {
+    t.info(event.keys)
+  })
+  t.fails(() => {
+    t.info(event.keys)
+  })
+}
+
 /**
 * @param {t.TestCase} tc
 */
@@ -337,6 +385,34 @@ export const testObserversUsingObservedeep = tc => {
  compare(users)
 }

+/**
+ * @param {t.TestCase} tc
+ */
+export const testPathsOfSiblingEvents = tc => {
+  const { users, map0 } = init(tc, { users: 2 })
+  /**
+   * @type {Array<Array<string|number>>}
+   */
+  const pathes = []
+  let calls = 0
+  const doc = users[0]
+  map0.set('map', new Y.Map())
+  map0.get('map').set('text1', new Y.Text('initial'))
+  map0.observeDeep(events => {
+    events.forEach(event => {
+      pathes.push(event.path)
+    })
+    calls++
+  })
+  doc.transact(() => {
+    map0.get('map').get('text1').insert(0, 'post-')
+    map0.get('map').set('text2', new Y.Text('new'))
+  })
+  t.assert(calls === 1)
+  t.compare(pathes, [['map'], ['map', 'text1']])
+  compare(users)
+}
+
 // TODO: Test events in Y.Map
 /**
 * @param {Object<string,any>} is
@@ -455,9 +531,9 @@ export const testChangeEvent = tc => {
 }

 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testYmapEventExceptionsShouldCompleteTransaction = tc => {
+export const testYmapEventExceptionsShouldCompleteTransaction = _tc => {
  const doc = new Y.Doc()
  const map = doc.getMap('map')

--- a/tests/y-text.tests.js
+++ b/tests/y-text.tests.js
--- a/tests/y-xml.tests.js
+++ b/tests/y-xml.tests.js
@@ -3,6 +3,33 @@ import * as Y from '../src/index.js'

 import * as t from 'lib0/testing'

+export const testCustomTypings = () => {
+  const ydoc = new Y.Doc()
+  const ymap = ydoc.getMap()
+  /**
+   * @type {Y.XmlElement<{ num: number, str: string, [k:string]: object|number|string }>}
+   */
+  const yxml = ymap.set('yxml', new Y.XmlElement('test'))
+  /**
+   * @type {number|undefined}
+   */
+  const num = yxml.getAttribute('num')
+  /**
+   * @type {string|undefined}
+   */
+  const str = yxml.getAttribute('str')
+  /**
+   * @type {object|number|string|undefined}
+   */
+  const dtrn = yxml.getAttribute('dtrn')
+  const attrs = yxml.getAttributes()
+  /**
+   * @type {object|number|string|undefined}
+   */
+  const any = attrs.shouldBeAny
+  console.log({ num, str, dtrn, attrs, any })
+}
+
 /**
 * @param {t.TestCase} tc
 */
@@ -92,9 +119,9 @@ export const testTreewalker = tc => {
 }

 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testYtextAttributes = tc => {
+export const testYtextAttributes = _tc => {
  const ydoc = new Y.Doc()
  const ytext = /** @type {Y.XmlText} */ (ydoc.get('', Y.XmlText))
  ytext.observe(event => {
@@ -106,9 +133,9 @@ export const testYtextAttributes = tc => {
 }

 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testSiblings = tc => {
+export const testSiblings = _tc => {
  const ydoc = new Y.Doc()
  const yxml = ydoc.getXmlFragment()
  const first = new Y.XmlText()
@@ -122,9 +149,9 @@ export const testSiblings = tc => {
 }

 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testInsertafter = tc => {
+export const testInsertafter = _tc => {
  const ydoc = new Y.Doc()
  const yxml = ydoc.getXmlFragment()
  const first = new Y.XmlText()
@@ -152,9 +179,9 @@ export const testInsertafter = tc => {
 }

 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testClone = tc => {
+export const testClone = _tc => {
  const ydoc = new Y.Doc()
  const yxml = ydoc.getXmlFragment()
  const first = new Y.XmlText('text')
@@ -170,9 +197,9 @@ export const testClone = tc => {
 }

 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
 */
-export const testFormattingBug = tc => {
+export const testFormattingBug = _tc => {
  const ydoc = new Y.Doc()
  const yxml = /** @type {Y.XmlText} */ (ydoc.get('', Y.XmlText))
  const delta = [
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,64 +1,21 @@
 {
  "compilerOptions": {
-    /* Basic Options */
-    "target": "es2018",
-    "lib": ["es2018", "dom"],                             /* Specify library files to be included in the compilation. */
-    "allowJs": true,                       /* Allow javascript files to be compiled. */
-    "checkJs": true,                       /* Report errors in .js files. */
-    // "jsx": "preserve",                     /* Specify JSX code generation: 'preserve', 'react-native', or 'react'. */
-    "declaration": true,                   /* Generates corresponding '.d.ts' file. */
-    // "declarationMap": true,                /* Generates a sourcemap for each corresponding '.d.ts' file. */
-    // "sourceMap": true,                     /* Generates corresponding '.map' file. */
-    // "outFile": "./dist/yjs.js",                       /* Concatenate and emit output to single file. */
-    "outDir": "./dist",                        /* Redirect output structure to the directory. */
-    "rootDir": "./",                       /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
-    // "composite": true,                     /* Enable project compilation */
-    // "removeComments": true,                /* Do not emit comments to output. */
-    // "noEmit": true,                        /* Do not emit outputs. */
-    // "importHelpers": true,                 /* Import emit helpers from 'tslib'. */
-    // "downlevelIteration": true,            /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */
-    // "isolatedModules": true,               /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */
-
-    /* Strict Type-Checking Options */
-    "strict": true,                           /* Enable all strict type-checking options. */
-    "noImplicitAny": true,                 /* Raise error on expressions and declarations with an implied 'any' type. */
+    "target": "ES2021",
+    "lib": ["ES2021", "dom"],
+    "module": "node16",
+    "allowJs": true,
+    "checkJs": true,
+    "declaration": true,
+    "declarationMap": true,
+    "outDir": "./dist",
+    "baseUrl": "./",
    "emitDeclarationOnly": true,
-    // "strictNullChecks": true,              /* Enable strict null checks. */
-    // "strictFunctionTypes": true,           /* Enable strict checking of function types. */
-    // "strictPropertyInitialization": true,  /* Enable strict checking of property initialization in classes. */
-    // "noImplicitThis": true,                /* Raise error on 'this' expressions with an implied 'any' type. */
-    // "alwaysStrict": true,                  /* Parse in strict mode and emit "use strict" for each source file. */
-
-    /* Additional Checks */
-    // "noUnusedLocals": true,                /* Report errors on unused locals. */
-    // "noUnusedParameters": true,            /* Report errors on unused parameters. */
-    // "noImplicitReturns": true,             /* Report error when not all code paths in function return a value. */
-    // "noFallthroughCasesInSwitch": true,    /* Report errors for fallthrough cases in switch statement. */
-
-    /* Module Resolution Options */
-    "moduleResolution": "node",            /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */
-    "baseUrl": "./",                       /* Base directory to resolve non-absolute module names. */
+    "strict": true,
+    "noImplicitAny": true,
+    "moduleResolution": "nodenext",
    "paths": {
      "yjs": ["./src/index.js"]
-    },                           /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */
-    // "rootDirs": [],                        /* List of root folders whose combined content represents the structure of the project at runtime. */
-    // "typeRoots": [],                       /* List of folders to include type definitions from. */
-    // "types": [],                           /* Type declaration files to be included in compilation. */
-    // "allowSyntheticDefaultImports": true,  /* Allow default imports from modules with no default export. This does not affect code emit, just typechecking. */
-    "esModuleInterop": true,                   /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
-    // "preserveSymlinks": true,              /* Do not resolve the real path of symlinks. */
-
-    /* Source Map Options */
-    // "sourceRoot": "",                      /* Specify the location where debugger should locate TypeScript files instead of source locations. */
-    // "mapRoot": "",                         /* Specify the location where debugger should locate map files instead of generated locations. */
-    // "inlineSourceMap": true,               /* Emit a single file with source maps instead of having a separate file. */
-    // "inlineSources": true,                 /* Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set. */
-
-    /* Experimental Options */
-    // "experimentalDecorators": true,        /* Enables experimental support for ES7 decorators. */
-    // "emitDecoratorMetadata": true,         /* Enables experimental support for emitting type metadata for decorators. */
-    // "maxNodeModuleJsDepth": 0,
-    // "types": ["./src/utils/typedefs.js"]
+    }
  },
  "include": ["./src/**/*.js", "./tests/**/*.js"]
 }
Author	SHA1	Message	Date
Kevin Jahns	415a645874	13.6.11	2024-01-21 11:30:14 +01:00
Kevin Jahns	1cb52dc863	fix Y.Text formatting issue - closes #606	2024-01-21 11:27:12 +01:00
Kevin Jahns	7a8ca6eaa5	add linear as a user of Yjs	2024-01-15 14:11:28 +01:00
Kevin Jahns	e348255bb1	Merge pull request #604 from lukasz-jazwa/proffesional-support-section Updated readme.md with Professional Support section	2024-01-10 17:27:03 +01:00
Kevin Jahns	79c095d4dc	Merge pull request #605 from xaviergonz/patch-1 Update README.md with mobx-keystone binding	2023-12-28 15:31:00 +01:00
Javier Gonzalez	0241fd3c40	Update README.md with mobx-keystone binding	2023-12-23 11:16:57 +01:00
lukasz jazwa	cf78ce12b2	Updated readme.md with Professional Support section	2023-12-14 21:55:53 +01:00
Kevin Jahns	77bd74127d	Update who-is-using (Cargo.site)	2023-12-11 16:37:23 +01:00
Kevin Jahns	fe36ffd122	add AWS Sagemaker, JupyterLab, JupyterCAD as users	2023-11-28 16:22:37 +01:00
Kevin Jahns	28ccd5e0dd	add providers (also mention some y-crdt based providers)	2023-11-21 19:55:29 +01:00
Kevin Jahns	1d4f2e5435	13.6.10	2023-11-21 12:29:49 +01:00
Kevin Jahns	2c0daeb071	implement snapshot API for yxml.getAttributes. implements #543	2023-11-21 12:24:21 +01:00
Kevin Jahns	013b2b6886	13.6.9	2023-11-20 12:56:27 +01:00
Kevin Jahns	c2e7076400	add iterator type checks	2023-11-20 12:53:58 +01:00
Kevin Jahns	289ff16f66	Merge pull request #590 from haines/map-iterator-types Fix typing of `Y.Map` iterators	2023-11-20 12:40:42 +01:00
Kevin Jahns	9f8c55885f	update github workflow	2023-11-20 12:46:12 +01:00
Kevin Jahns	5861876e6f	Merge pull request #587 from SamyPesse/patch-1 Only emit "load" when sync is set to true	2023-11-20 12:36:25 +01:00
Kevin Jahns	37236fa31f	update license. closes #471	2023-11-20 12:39:51 +01:00
Kevin Jahns	b32f5434f1	Merge pull request #557 from tonny008/patch-1 fix comment in doc	2023-11-20 12:28:12 +01:00
Kevin Jahns	61e84c5f99	Merge pull request #579 from jsejcksn/fix/docs/readme docs(readme): fix typo	2023-11-20 12:27:12 +01:00
Kevin Jahns	b531438369	Merge pull request #595 from himself65/expose-content-doc feat: expose some types	2023-11-20 12:22:46 +01:00
Kevin Jahns	ac49dbcbd8	Merge pull request #583 from nikgraf/improve-docs add documentation on V2 events	2023-11-14 20:30:04 +01:00
Kevin Jahns	da8ca5168e	Merge pull request #596 from siddug/patch-1 Adding www.btw.so to the platforms who use Yjs	2023-11-11 11:16:19 +01:00
Siddhartha Gunti	a3d69bba72	Adding www.btw.so to the platforms who use Yjs Repo here: https://github.com/btw-so/btw	2023-11-07 18:54:22 +05:30
Alex Yang	e5f286cf89	feat: expose some types	2023-11-06 16:51:23 -06:00
Kevin Jahns	c14a8d70f1	Merge pull request #593 from himself65/remove-unused-check fix: remove unused if-statement check	2023-11-02 20:23:06 +01:00
Alex Yang	f52569b8fa	fix: remove unused if-statement check	2023-10-30 19:41:09 -05:00
Andrew Haines	25bef2308f	Fix typing of `Y.Map` iterators Signed-off-by: Andrew Haines <andrew@haines.org.nz>	2023-10-25 15:00:48 +01:00
Samy Pessé	e7572d61c6	Only emit "load" when sync is set to true	2023-10-22 11:03:25 +02:00
Nik Graf	e6afc51b84	add documentation on V2 events	2023-10-07 20:56:02 +02:00
Jesse Jackson	171d801e0a	docs(readme): fix typo Update link text for Swift bindings: from "yrb" to "yswift"	2023-10-05 00:41:48 -05:00
Kevin Jahns	9a7b659919	bump lib0	2023-09-23 16:59:32 +02:00
Kevin Jahns	e0a9c0d9bb	Merge pull request #577 from EricHasegawa/patch-1 Correct typos in INTERNALS.md	2023-09-19 13:15:58 +02:00
Eric Hasegawa	3a758f89a1	Correct typos in INTERNALS.md	2023-09-18 13:30:15 -07:00
Kevin Jahns	b5051e91ac	Merge pull request #533 from booxood/fix-docs-example docs: fix "Example: Syncing clients without loading the Y.Doc" code	2023-09-18 19:32:01 +02:00
Kevin Jahns	2fe8907ab0	13.6.8	2023-09-18 10:22:28 +02:00
Kevin Jahns	29270b5f3e	fix "can't read origin of undefined" - fixes #417	2023-09-18 09:55:50 +02:00
Kevin Jahns	a099e98bd6	create error on call - fixes #569	2023-09-07 13:41:35 +02:00
Kevin Jahns	1b0da31d00	Merge pull request #567 from stevenfabre/main Added Liveblocks Yjs to the list of providers	2023-09-06 17:01:29 +02:00
Kevin Jahns	a1fda219e4	lint readme	2023-09-02 17:39:49 +02:00
Kevin Jahns	09687221ac	Merge pull request #568 from himself65/docs-update docs: add `@toeverything/y-indexeddb`	2023-09-01 13:01:57 +02:00
Alex Yang	4d7a366f6e	docs: add `@toeverything/y-indexeddb`	2023-08-31 17:21:36 -05:00
Steven Fabre	0b30413f6e	Liveblocks in Yjs README Signed-off-by: Steven Fabre <hello@stevenfabre.com>	2023-08-31 05:34:05 -04:00
Kevin Jahns	eeae74decf	sponsors update	2023-08-29 16:34:26 +02:00
Kevin Jahns	5ac498d62e	Merge pull request #566 from IllumiDesk/docs/add-illumidesk-ref Adds IllumiDesk as a reference to the using list	2023-08-29 16:33:32 +02:00
Greg Werner	9a9a1ffeeb	Adds IllumiDesk as a reference to the using list Signed-off-by: Greg Werner <werner.greg@gmail.com>	2023-08-28 14:45:43 -04:00
Kevin Jahns	1ed12434a1	Merge pull request #556 from AdventureBeard/patch-1 Update README.md	2023-08-28 12:26:31 +02:00
Kevin Jahns	7a4975ee85	Merge branch 'main' into patch-1	2023-08-28 12:26:18 +02:00
Kevin Jahns	92ee76ad6e	Merge pull request #564 from akshaykmr/readme-update-who-is-using add oorja.io to who is using yjs	2023-08-24 14:01:32 +02:00
Kevin Jahns	97c09a6cca	fix #509	2023-08-24 13:52:38 +02:00
Kevin Jahns	2e3ba0f81f	Merge pull request #565 from himself65/himself65-patch-1 Update README.md	2023-08-23 16:46:17 +02:00
Alex Yang	61abf3a1db	Update README.md	2023-08-23 09:25:18 -05:00
Akshay Kumar	bd867cb161	add oorja to who is using yjs	2023-08-23 19:31:58 +05:30
Kevin Jahns	87b7d3e951	add Yjs-compatible ports to documentation	2023-08-23 15:42:48 +02:00
GQ	7bdf94167a	fix comment	2023-07-31 15:05:33 +08:00
Braden	03b9a806e8	Update README.md	2023-07-23 14:40:03 -05:00
Kevin Jahns	5ee6992d1f	13.6.7	2023-07-17 14:43:07 +02:00
Kevin Jahns	dd31040656	Merge pull request #553 from yjs/simpler-bulk-changes-fix-542 bulk-merging structs - replaces #542, fixes #541	2023-07-17 14:35:18 +02:00
Kevin Jahns	c77dedb68d	bulk-merging structs - replaces #542 , fixes #541	2023-07-17 14:29:54 +02:00
Kevin Jahns	90f2a06b5e	throw error when event changes are computed after a transaction	2023-06-27 13:20:53 +02:00
Kevin Jahns	8586806932	13.6.6	2023-06-25 19:10:34 +02:00
Kevin Jahns	981340139f	skip iterating when there are no formatting items - replaces #547	2023-06-25 12:46:02 +02:00
Kevin Jahns	b792902f17	13.6.5	2023-06-22 17:55:45 +02:00
Kevin Jahns	83b7c6839e	Merge pull request #548 from YousefED/fix/equalDeleteSets fix equalDeleteSets	2023-06-22 17:46:34 +02:00
Kevin Jahns	65c4d40a87	Merge branch 'NilSet-path-cache-invalidation'	2023-06-22 17:48:19 +02:00
Kevin Jahns	942c8a267b	remove duplicate Transaction.callAll logic	2023-06-22 17:46:49 +02:00
yousefed	eda085936a	keep original imports	2023-06-21 18:29:40 +02:00
yousefed	12be6c006a	fix equalDeleteSets	2023-06-21 18:28:53 +02:00
Noel Levy	5d862477cd	invalidate cached path when changing currentTarget of event fixes #544	2023-06-19 11:31:45 -07:00
Kevin Jahns	c398448152	add blocksuite editor by affine	2023-06-16 16:04:30 +02:00
Kevin Jahns	2fbba13246	13.6.4	2023-06-15 13:11:40 +02:00
Kevin Jahns	885a740470	heavily improve performance when there are many events	2023-06-15 13:09:30 +02:00
Kevin Jahns	aedd4c8bf3	13.6.3	2023-06-15 12:47:48 +02:00
Kevin Jahns	9563612126	Merge pull request #540 from yjs/ytext-cleanup-538-refactor Ytext cleanup 538 refactor	2023-06-15 12:39:12 +02:00
Kevin Jahns	ce098d0ac2	refactor #538 (formatting attrs) a bit	2023-06-15 12:40:28 +02:00
Noel Levy	08801dd406	scan the document once for all ytexts when cleaning up Fixes #522 but is a scarier change	2023-06-12 18:20:22 -07:00
Noel Levy	3741f43a11	group cleanups for YText changes into a single transaction Fixes #522 but is still massively slow	2023-06-12 16:56:19 -07:00
Kevin Jahns	00ef472d68	13.6.2	2023-06-08 11:19:06 +02:00
Kevin Jahns	719858201a	implement snapshotContainsUpdate	2023-06-08 11:14:49 +02:00
Liucw	1ce1751432	docs: fix "Example: Syncing clients without loading the Y.Doc" code	2023-05-17 14:52:25 +08:00
Kevin Jahns	5db1eed181	Merge pull request #528 from jamesgpearce/patch-1 Add missing getting-started steps	2023-05-05 12:21:56 +02:00
Kevin Jahns	2e9a648d08	13.6.1	2023-05-04 11:29:08 +02:00
Kevin Jahns	83712cb1a6	update typings of getAttributes	2023-05-04 11:26:11 +02:00
Kevin Jahns	30b56d5ae9	Enable typings for inserting custom attrs in YXmlElement - fixes #531	2023-05-04 10:07:05 +02:00
James Pearce	61eeaef226	Add missing getting-started steps	2023-04-30 16:31:46 -04:00
Kevin Jahns	adaa95ebb8	add example to createDocFromSnapshot - #159	2023-04-27 18:08:28 +02:00
Kevin Jahns	1f2f08ef7e	13.6.0	2023-04-22 18:41:44 +02:00
Kevin Jahns	39167e6e2a	Implement function that obfuscates a ydoc and scrambles its content	2023-04-22 18:39:29 +02:00
Kevin Jahns	5a8519d2c2	13.5.53	2023-04-18 20:09:59 +02:00
Kevin Jahns	d039d48b3f	ytext: diff should never create useless delta op	2023-04-18 20:07:17 +02:00
Kevin Jahns	710ac31af3	13.5.52	2023-04-03 14:12:34 +02:00
Kevin Jahns	49f435284f	lint	2023-04-03 14:10:26 +02:00
Kevin Jahns	ba96f2fe74	implement fix for #500 . extends #515	2023-04-03 14:02:37 +02:00
Dominik Henneke	99bab4a1d8	Fix lint errors	2023-04-03 14:02:37 +02:00
Dominik Henneke	1674d3986d	Restore deleted entries in a map	2023-04-03 14:02:37 +02:00
Kevin Jahns	dc3e99e6a1	Merge pull request #518 from WofWca/jsdoc-yarray docs: fix JSDoc typo	2023-04-02 11:47:46 +02:00
WofWca	fb6664a2bc	docs: fix JSDoc typo	2023-04-01 23:12:49 +08:00
Kevin Jahns	0d7e865531	13.5.51	2023-03-22 11:05:23 +01:00
Kevin Jahns	e73eb0bf92	use lib0 conditional exports in cjs file	2023-03-22 11:02:55 +01:00
Kevin Jahns	d815855450	specify engine	2023-03-21 11:27:37 +01:00
Kevin Jahns	61ba6cdde1	bump ci to use current nodejs versions	2023-03-21 11:22:59 +01:00
Kevin Jahns	cb70d7bad3	fix typings and lib0 resolution	2023-03-21 11:14:37 +01:00
Kevin Jahns	2001bec8eb	modernize tsconfig	2023-03-11 12:20:52 +01:00
Kevin Jahns	2e2710ded9	13.5.50	2023-03-11 09:15:11 +01:00
Kevin Jahns	227018f5c7	toDelta doesnt create transaction - fixes #506	2023-03-11 09:13:27 +01:00
Kevin Jahns	da8bacfc78	add tests for complex Y.Text deltas	2023-03-10 12:53:48 +01:00
Kevin Jahns	92bad63145	add docs: tr.changes should only be computed during the event	2023-03-09 18:44:43 +01:00
Kevin Jahns	52ff230dd1	13.5.49	2023-03-09 13:59:08 +01:00
Kevin Jahns	fe48efe64f	fix generating too many cleanup transactions. closes #506	2023-03-09 13:45:13 +01:00
Kevin Jahns	7e40fc442d	13.5.48	2023-03-02 19:50:34 +01:00
Kevin Jahns	035e350062	optimize formatting cleanup	2023-03-02 19:48:00 +01:00
Kevin Jahns	bf338d8040	fix attribute update issue - fixes #503	2023-03-02 19:08:01 +01:00
Kevin Jahns	658c520b93	13.5.47	2023-02-21 14:37:24 +01:00
Kevin Jahns	2576d4efca	increasing sort of ds encoding	2023-02-21 14:35:28 +01:00
Kevin Jahns	58b754950e	Merge pull request #439 from Synthesia-Technologies/feat/deterministic-update-encoding Make encodeStateAsUpdate deterministic	2023-02-21 10:59:31 +01:00
Kevin Jahns	ea7ad07f34	13.5.46	2023-02-14 16:21:01 +01:00
Kevin Jahns	1c999b250e	fix #474 - formatting bug	2023-02-14 16:19:22 +01:00
Kevin Jahns	e9189365ee	add debugging case for #474 - unfininished	2023-02-13 14:27:57 +01:00
Kevin Jahns	e0a2f11db3	13.5.45	2023-01-31 12:57:56 +01:00
Kevin Jahns	7445a9ce5f	add whenSynced and isSynced property with refined logic	2023-01-31 12:56:07 +01:00
Kevin Jahns	7f6c12a541	bump typescript and fix type issues	2023-01-31 12:16:03 +01:00
Kevin Jahns	370d0c138d	Merge pull request #496 from neftaly/array.from Add test for Y.Array.from	2023-01-25 13:12:52 +01:00
Neftaly Hernandez	d29de75f85	Add test for Y.Array.from	2023-01-23 06:41:57 +00:00
Kevin Jahns	f215866429	remove poxi on request..	2023-01-19 15:24:53 +01:00
Kevin Jahns	093b41ccc4	Merge pull request #495 from laem/patch-1 New user	2023-01-19 15:20:41 +01:00
Mael	ab60cd1ff8	New user	2023-01-19 15:06:20 +01:00
Kevin Jahns	1130abe05b	add POXi as a user	2023-01-18 12:20:52 +01:00
Kevin Jahns	31b4ab8d0c	13.5.44	2023-01-01 18:25:03 +01:00
Kevin Jahns	ab978b2003	add exports.module field - #438	2023-01-01 18:23:21 +01:00
Kevin Jahns	afc6728c9e	13.5.43	2022-11-30 12:28:28 +01:00
Kevin Jahns	0ef5bd42fe	lint readme	2022-11-30 12:26:55 +01:00
Kevin Jahns	3ece681758	allow transactions within event handlers having different origins	2022-11-30 12:09:19 +01:00
Kevin Jahns	cac9407185	remove snapshot param in yxml.getAttributes	2022-11-30 11:34:34 +01:00
Kevin Jahns	7ea8ffebae	Merge pull request #482 from joakim/patch-2 Add missing word	2022-11-08 16:30:12 +01:00
Joakim	d7751c16fd	Add missing word	2022-11-05 21:15:33 +01:00
Kevin Jahns	a64c51ec06	Merge pull request #478 from ViktorQvarfordt/patch-1 Add Sana to -Who Is Using Yjs-	2022-10-24 13:10:31 +02:00
Viktor Qvarfordt	7405057037	Add Sana to -Who Is Using Yjs-	2022-10-23 21:34:43 +02:00
Kevin Jahns	6208b82872	13.5.42	2022-10-18 16:52:38 +02:00
Kevin Jahns	12a9134b09	lint	2022-10-18 16:51:07 +02:00
Kevin Jahns	7395229086	Port test from @PatrickShaw #432 . Allow infinite captureTimeout in UndoManager #431 . Closes #432	2022-10-18 16:45:30 +02:00
Kevin Jahns	8fb73edd97	Merge pull request #453 from Cargo/main Allow updating captureTimeout on UndoManager instances	2022-10-03 11:58:03 +02:00
Kevin Jahns	f1ad5686c1	Add Hyperquery to -Who Is Using Yjs-	2022-10-02 17:10:14 +02:00
Kevin Jahns	ed9236bdc7	Merge pull request #464 from MaxNoetzold/main Add y-mongodb-provider to provider list in README	2022-09-26 22:08:43 +02:00
Kevin Jahns	5405fd2d7c	Merge pull request #465 from neo/patch-1 Remove unused return in `forEach` of `YMap`	2022-09-20 13:07:23 +02:00
Wenchen Li	12667f6b66	Remove unused return in `forEach` of `YMap` If the idea is to keep the API as close to the JS Map as possible, maybe we should consider not returning here. Ref: https://github.com/microsoft/TypeScript/blob/v4.8.3/lib/lib.es2015.collection.d.ts#L28-L31	2022-09-19 18:19:41 -04:00
MaxNoetzold	3d7ef7e28b	add y-mongodb-provider to provider list in README	2022-09-18 14:17:52 +02:00
Kevin Jahns	56267e0a7d	Merge pull request #455 from scenaristeur/patch-1 Update INTERNALS.md	2022-09-16 23:26:04 +02:00
Kevin Jahns	da71f6fa45	Merge pull request #463 from doodlewind/patch-1 add AFFiNE to sponsor list	2022-09-14 17:43:04 +02:00
Kevin Jahns	588788fbef	fix snapshot diff calculation naming bug	2022-09-14 00:37:06 +02:00
Yifeng Wang	fb9df6efe2	add AFFiNE to sponsor list	2022-09-13 21:31:10 +08:00
Kevin Jahns	a69ecb0287	Merge pull request #460 from regischen/fix-typo fix typo	2022-08-25 12:03:42 +02:00
regischen	923fc6e06e	fix typo	2022-08-25 17:35:24 +08:00
David	0fdfd93e4b	Update INTERNALS.md Typo	2022-08-14 10:10:14 +02:00
Aart Rost	e0e5f8d2ea	Allow updating captureTimeout on UndoManager instances Used to pause the undoManager by toggling the timeout with `yUndoManager.captureTimeout = Number.MAX_VALUE`	2022-08-10 14:07:40 -07:00
Kevin Jahns	daf034cf75	Merge pull request #452 from aryzing/patch-1 Update README.md	2022-08-08 10:57:13 +02:00
Eduard Bardají Puig	2157ebb4d0	Update README.md Add missing `.getText()` method to docs.	2022-08-07 20:52:16 +02:00
Kevin Jahns	97ef4ae1e0	13.5.41	2022-07-28 14:14:27 +02:00
Kevin Jahns	df2d59e2fb	UndoManager: fix special deletion case. closes #447 closes #443	2022-07-28 14:12:21 +02:00
Kevin Jahns	7a61c90261	13.5.40	2022-07-22 14:24:44 +02:00
Kevin Jahns	6fa8778fc7	add doc parameter to UndoManager	2022-07-22 14:22:46 +02:00
Adam Chelminski	6b7b3136e0	delete set encoding should be in descending order	2022-06-23 16:01:29 +02:00
Adam Chelminski	da052bdb0a	Make encodeStateAsUpdate deterministic	2022-06-23 15:50:35 +02:00
Kevin Jahns	1bc9308566	improve already-imported message further	2022-06-16 12:57:04 +02:00
Kevin Jahns	a5e0448a92	Merge pull request #434 from PatrickShaw/globalThis-add Prefer globalThis over window and global	2022-06-15 12:04:09 +02:00
Kevin Jahns	c0c2b3347b	13.5.39	2022-06-15 10:49:48 +02:00
Kevin Jahns	6258ba1ce9	Merge pull request #435 from yogas/export_UpdateEncoderV1 export UpdateEncoderV1	2022-06-15 10:47:04 +02:00
Vladimir Shapovalov	5a7ee74f68	export UpdateEncoderV1	2022-06-14 13:16:35 +07:00
Kevin Jahns	29fb4a0aab	improve double-import error message	2022-06-13 10:27:04 +02:00
Patrick Shaw	8937494bdd	Added globalThis	2022-06-01 13:36:32 +10:00
Kevin Jahns	4504196d5c	add gitter & discord link	2022-05-19 22:15:10 +02:00
Kevin Jahns	0c8d29bfff	Merge pull request #424 from KentoMoriwaki/patch-1 Add support for esm in node.js	2022-05-17 14:38:25 +02:00
Kento Moriwaki	43384e4148	Add support for esm in node.js	2022-05-17 21:18:04 +09:00
Kevin Jahns	a2b62b0a58	13.5.38	2022-05-14 18:11:57 +02:00
Kevin Jahns	6febf51b1a	fix captureTransaction	2022-05-14 18:10:19 +02:00
Kevin Jahns	5a4816a1b2	13.5.37	2022-05-14 14:25:28 +02:00
Kevin Jahns	4ad8af9a80	Add option to UndoManager to filter transactions	2022-05-14 14:23:47 +02:00