Merge pull request #702 from kapv89/patch-1

Update README.md to add https://github.com/kapv89/k_yrs_go to persistence providers

README.md

@@ -99,7 +99,6 @@ Showcase](https://yjs-diagram.synergy.codes/).
 * [AWS SageMaker](https://aws.amazon.com/sagemaker/) Tools for building Machine
   Learning Models
 * [linear](https://linear.app) Streamline issues, projects, and product roadmaps.
-* [btw](https://www.btw.so) - Personal website builder
 * [AWS SageMaker](https://aws.amazon.com/sagemaker/) - Machine Learning Service
 * [Arkiter](https://www.arkiter.com/) - Live interview software
 * [Appflowy](https://www.appflowy.io/) - They use Yrs
@@ -165,6 +164,7 @@ are implemented in separate modules.
 | 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) |
 | [PSPDFKit](https://www.nutrient.io/) |  | [yjs-pspdfkit](https://github.com/hoangqwe159/yjs-pspdfkit) | [demo](https://github.com/hoangqwe159/yjs-pspdfkit) |
+| [Rows n'Columns](https://www.rowsncolumns.app/) | ✔ | [@rowsncolumns/y-spreadsheet](https://docs.rowsncolumns.app/collaboration/yjs-collaboration) | |
 
 ### Providers
 
@@ -300,6 +300,10 @@ A database and connection provider for Yjs based on Firestore.
   Provides persistent storage for a web server using PostgreSQL and
   is easily compatible with y-websocket.  
   </dd>
+  <dt><a href="https://github.com/kapv89/k_yrs_go">k_yrs_go</a></dt>
+  <dd>
+  Golang database server for YJS CRDT using Postgres + Redis
+  </dd>
 </dl>
 
 ### Tooling

funding.json

@@ -34,20 +34,19 @@
       ]
     },
     {
-      "guid": "ystream",
+      "guid": "Titanic",
-      "name": "Y/Stream",
+      "name": "Y/Titanic",
       "description": "A provider for syncing millions of docs efficiently with other peers. This will become the foundation for building real local-first apps with Yjs.",
       "webpageUrl": {
-        "url": "https://github.com/yjs/ystream",
+        "url": "https://github.com/yjs/titanic",
-        "wellKnown": "https://github.com/yjs/ystream/blob/main/.well-known/funding-manifest-urls"
+        "wellKnown": "https://github.com/yjs/titanic/blob/main/.well-known/funding-manifest-urls"
       },
       "repositoryUrl": {
-        "url": "https://github.com/yjs/ystream",
+        "url": "https://github.com/yjs/titanic",
-        "wellKnown": "https://github.com/yjs/ystream/blob/main/.well-known/funding-manifest-urls"
+        "wellKnown": "https://github.com/yjs/titanic/blob/main/.well-known/funding-manifest-urls"
       },
       "licenses": [
-        "spdx:MIT",
+        "spdx:MIT"
-        "spdx:GPL-3.0"
       ],
       "tags": [
         "privacy",
@@ -90,9 +89,9 @@
         ]
       },
       {
-        "guid": "ystream-funding",
+        "guid": "titanic-funding",
         "status": "active",
-        "name": "YStream Funding",
+        "name": "Titanic Funding",
         "description": "Fund the next generation of local-first providers.",
         "amount": 30000,
         "currency": "USD",

src/utils/UndoManager.js

@@ -159,7 +159,7 @@ const popStackItem = (undoManager, stack, eventType) => {
  */
 export class UndoManager extends ObservableV2 {
   /**
-   * @param {Doc|AbstractType<any>|Array<AbstractType<any>>} typeScope Accepts either a single type, or an array of types
+   * @param {Doc|AbstractType<any>|Array<AbstractType<any>>} typeScope Limits the scope of the UndoManager. If this is set to a ydoc instance, all changes on that ydoc will be undone. If set to a specific type, only changes on that type or its children will be undone. Also accepts an array of types.
    * @param {UndoManagerOptions} options
    */
   constructor (typeScope, {
@@ -272,6 +272,8 @@ export class UndoManager extends ObservableV2 {
   }
 
   /**
+   * Extend the scope.
+   *
    * @param {Array<AbstractType<any> | Doc> | AbstractType<any> | Doc} ytypes
    */
   addToScope (ytypes) {

tests/undo-redo.tests.js

@@ -116,6 +116,59 @@ export const testEmptyTypeScope = _tc => {
   t.assert(yarray.length === 0)
 }
 
+/**
+ * @param {t.TestCase} _tc
+ */
+export const testRejectUpdateExample = _tc => {
+  const tmpydoc1 = new Y.Doc()
+  tmpydoc1.getArray('restricted').insert(0, [1])
+  tmpydoc1.getArray('public').insert(0, [1])
+  const update1 = Y.encodeStateAsUpdate(tmpydoc1)
+  const tmpydoc2 = new Y.Doc()
+  tmpydoc2.getArray('public').insert(0, [2])
+  const update2 = Y.encodeStateAsUpdate(tmpydoc2)
+
+  const ydoc = new Y.Doc()
+  const restrictedType = ydoc.getArray('restricted')
+
+  /**
+   * Assume this function handles incoming updates via a communication channel like websockets.
+   * Changes to the `ydoc.getMap('restricted')` type should be rejected.
+   *
+   * - set up undo manager on the restricted types
+   * - cache pending* updates from the Ydoc to avoid certain attacks
+   * - apply received update and check whether the restricted type (or any of its children) has been changed.
+   * - catch errors that might try to circumvent the restrictions
+   * - undo changes on restricted types
+   * - reapply pending* updates
+   *
+   * @param {Uint8Array} update
+   */
+  const updateHandler = (update) => {
+    // don't handle changes of the local undo manager, which is used to undo invalid changes
+    const um = new Y.UndoManager(restrictedType, { trackedOrigins: new Set(['remote change']) })
+    const beforePendingDs = ydoc.store.pendingDs
+    const beforePendingStructs = ydoc.store.pendingStructs?.update
+    try {
+      Y.applyUpdate(ydoc, update, 'remote change')
+    } finally {
+      while (um.undoStack.length) {
+        um.undo()
+      }
+      um.destroy()
+      ydoc.store.pendingDs = beforePendingDs
+      ydoc.store.pendingStructs = null
+      if (beforePendingStructs) {
+        Y.applyUpdateV2(ydoc, beforePendingStructs)
+      }
+    }
+  }
+  updateHandler(update1)
+  updateHandler(update2)
+  t.assert(restrictedType.length === 0)
+  t.assert(ydoc.getArray('public').length === 2)
+}
+
 /**
  * Test case to fix #241
  * @param {t.TestCase} _tc