Prevent mutations of js-sdk owned objects as it breaks accountData

src/Rooms.ts

@@ -15,6 +15,7 @@ limitations under the License.
 */
 
 import { Room } from "matrix-js-sdk/src/models/room";
+import { EventType } from "matrix-js-sdk/src/@types/event";
 
 import { MatrixClientPeg } from './MatrixClientPeg';
 import AliasCustomisations from './customisations/Alias';
@@ -90,10 +91,10 @@ export function guessAndSetDMRoom(room: Room, isDirect: boolean): Promise<void>
 export async function setDMRoom(roomId: string, userId: string): Promise<void> {
     if (MatrixClientPeg.get().isGuest()) return;
 
-    const mDirectEvent = MatrixClientPeg.get().getAccountData('m.direct');
+    const mDirectEvent = MatrixClientPeg.get().getAccountData(EventType.Direct);
     let dmRoomMap = {};
 
-    if (mDirectEvent !== undefined) dmRoomMap = mDirectEvent.getContent();
+    if (mDirectEvent !== undefined) dmRoomMap = { ...mDirectEvent.getContent() }; // copy as we will mutate
 
     // remove it from the lists of any others users
     // (it can only be a DM room for one person)
@@ -117,7 +118,7 @@ export async function setDMRoom(roomId: string, userId: string): Promise<void> {
         dmRoomMap[userId] = roomList;
     }
 
-    await MatrixClientPeg.get().setAccountData('m.direct', dmRoomMap);
+    await MatrixClientPeg.get().setAccountData(EventType.Direct, dmRoomMap);
 }
 
 /**

src/components/structures/MatrixChat.tsx

@@ -15,7 +15,7 @@ limitations under the License.
 */
 
 import React, { ComponentType, createRef } from 'react';
-import { createClient, MatrixClient } from 'matrix-js-sdk/src/matrix';
+import { createClient, EventType, MatrixClient } from 'matrix-js-sdk/src/matrix';
 import { ISyncStateData, SyncState } from 'matrix-js-sdk/src/sync';
 import { MatrixError } from 'matrix-js-sdk/src/http-api';
 import { InvalidStoreError } from "matrix-js-sdk/src/errors";
@@ -1297,16 +1297,10 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
             // run without the update to m.direct, making another welcome
             // user room (it doesn't wait for new data from the server, just
             // the saved sync to be loaded).
-            const saveWelcomeUser = (ev) => {
-                if (
-                    ev.getType() === 'm.direct' &&
-                    ev.getContent() &&
-                    ev.getContent()[this.props.config.welcomeUserId]
-                ) {
+            const saveWelcomeUser = (ev: MatrixEvent) => {
+                if (ev.getType() === EventType.Direct && ev.getContent()[this.props.config.welcomeUserId]) {
                     MatrixClientPeg.get().store.save(true);
-                    MatrixClientPeg.get().removeListener(
-                        "accountData", saveWelcomeUser,
-                    );
+                    MatrixClientPeg.get().removeListener("accountData", saveWelcomeUser);
                 }
             };
             MatrixClientPeg.get().on("accountData", saveWelcomeUser);

src/stores/room-list/RoomListStore.ts

@@ -18,6 +18,7 @@ import { MatrixClient } from "matrix-js-sdk/src/client";
 import { Room } from "matrix-js-sdk/src/models/room";
 import { isNullOrUndefined } from "matrix-js-sdk/src/utils";
 import { logger } from "matrix-js-sdk/src/logger";
+import { EventType } from "matrix-js-sdk/src/@types/event";
 
 import SettingsStore from "../../settings/SettingsStore";
 import { DefaultTagID, isCustomTag, OrderedDefaultTagIDs, RoomUpdateCause, TagID } from "./models";
@@ -281,7 +282,7 @@ export class RoomListStoreClass extends AsyncStoreWithClient<IState> {
             }
             await this.handleRoomUpdate(room, RoomUpdateCause.Timeline);
             this.updateFn.trigger();
-        } else if (payload.action === 'MatrixActions.accountData' && payload.event_type === 'm.direct') {
+        } else if (payload.action === 'MatrixActions.accountData' && payload.event_type === EventType.Direct) {
             const eventPayload = (<any>payload); // TODO: Type out the dispatcher types
             const dmMap = eventPayload.event.getContent();
             for (const userId of Object.keys(dmMap)) {

src/utils/DMRoomMap.ts

@@ -18,6 +18,8 @@ import { uniq } from "lodash";
 import { Room } from "matrix-js-sdk/src/models/room";
 import { MatrixClient } from "matrix-js-sdk/src/client";
 import { logger } from "matrix-js-sdk/src/logger";
+import { EventType } from "matrix-js-sdk/src/@types/event";
+import { MatrixEvent } from "matrix-js-sdk/src/models/event";
 
 import { MatrixClientPeg } from '../MatrixClientPeg';
 
@@ -35,14 +37,14 @@ export default class DMRoomMap {
     private roomToUser: {[key: string]: string} = null;
     private userToRooms: {[key: string]: string[]} = null;
     private hasSentOutPatchDirectAccountDataPatch: boolean;
-    private mDirectEvent: object;
+    private mDirectEvent: {[key: string]: string[]};
 
     constructor(private readonly matrixClient: MatrixClient) {
         // see onAccountData
         this.hasSentOutPatchDirectAccountDataPatch = false;
 
-        const mDirectEvent = matrixClient.getAccountData('m.direct');
-        this.mDirectEvent = mDirectEvent ? mDirectEvent.getContent() : {};
+        const mDirectEvent = matrixClient.getAccountData(EventType.Direct)?.getContent() ?? {};
+        this.mDirectEvent = { ...mDirectEvent }; // copy as we will mutate
     }
 
     /**
@@ -81,9 +83,9 @@ export default class DMRoomMap {
         this.matrixClient.removeListener("accountData", this.onAccountData);
     }
 
-    private onAccountData = (ev) => {
-        if (ev.getType() == 'm.direct') {
-            this.mDirectEvent = this.matrixClient.getAccountData('m.direct').getContent() || {};
+    private onAccountData = (ev: MatrixEvent) => {
+        if (ev.getType() == EventType.Direct) {
+            this.mDirectEvent = { ...ev.getContent() }; // copy as we will mutate
             this.userToRooms = null;
             this.roomToUser = null;
         }
@@ -94,7 +96,7 @@ export default class DMRoomMap {
      * with ourself, not the other user. Fix it by guessing the other user and
      * modifying userToRooms
      */
-    private patchUpSelfDMs(userToRooms) {
+    private patchUpSelfDMs(userToRooms: Record<string, string[]>) {
         const myUserId = this.matrixClient.getUserId();
         const selfRoomIds = userToRooms[myUserId];
         if (selfRoomIds) {
@@ -130,7 +132,7 @@ export default class DMRoomMap {
         }
     }
 
-    public getDMRoomsForUserId(userId): string[] {
+    public getDMRoomsForUserId(userId: string): string[] {
         // Here, we return the empty list if there are no rooms,
         // since the number of conversations you have with this user is zero.
         return this.getUserToRooms()[userId] || [];
@@ -189,10 +191,10 @@ export default class DMRoomMap {
 
     private getUserToRooms(): {[key: string]: string[]} {
         if (!this.userToRooms) {
-            const userToRooms = this.mDirectEvent as {[key: string]: string[]};
+            const userToRooms = this.mDirectEvent;
             const myUserId = this.matrixClient.getUserId();
             const selfDMs = userToRooms[myUserId];
-            if (selfDMs && selfDMs.length) {
+            if (selfDMs?.length) {
                 const neededPatching = this.patchUpSelfDMs(userToRooms);
                 // to avoid multiple devices fighting to correct
                 // the account data, only try to send the corrected
@@ -201,7 +203,7 @@ export default class DMRoomMap {
                     `(self-chats that shouldn't be), patching it up.`);
                 if (neededPatching && !this.hasSentOutPatchDirectAccountDataPatch) {
                     this.hasSentOutPatchDirectAccountDataPatch = true;
-                    this.matrixClient.setAccountData('m.direct', userToRooms);
+                    this.matrixClient.setAccountData(EventType.Direct, userToRooms);
                 }
             }
             this.userToRooms = userToRooms;