Merge pull request #2826 from robintown/init-leave-race

Resolve races between `initLocalCallFeed` and `leave`

spec/unit/webrtc/groupCall.spec.ts

@@ -23,7 +23,7 @@ import {
     Room,
     RoomMember,
 } from '../../../src';
-import { GroupCall, GroupCallEvent } from "../../../src/webrtc/groupCall";
+import { GroupCall, GroupCallEvent, GroupCallState } from "../../../src/webrtc/groupCall";
 import { MatrixClient } from "../../../src/client";
 import {
     installWebRTCMocks,
@@ -174,6 +174,13 @@ describe('Group Call', function() {
             groupCall.leave();
         });
 
+        it("stops initializing local call feed when leaving", async () => {
+            const initPromise = groupCall.initLocalCallFeed();
+            groupCall.leave();
+            await expect(initPromise).rejects.toBeDefined();
+            expect(groupCall.state).toBe(GroupCallState.LocalCallFeedUninitialized);
+        });
+
         it("sends state event to room when creating", async () => {
             await groupCall.create();
 

src/webrtc/groupCall.ts

@@ -257,13 +257,26 @@ export class GroupCall extends TypedEventEmitter<
 
         let stream: MediaStream;
 
+        let disposed = false;
+        const onState = (state: GroupCallState) => {
+            if (state === GroupCallState.LocalCallFeedUninitialized) {
+                disposed = true;
+            }
+        };
+        this.on(GroupCallEvent.GroupCallStateChanged, onState);
+
         try {
             stream = await this.client.getMediaHandler().getUserMediaStream(true, this.type === GroupCallType.Video);
         } catch (error) {
             this.setState(GroupCallState.LocalCallFeedUninitialized);
             throw error;
+        } finally {
+            this.off(GroupCallEvent.GroupCallStateChanged, onState);
         }
 
+        // The call could've been disposed while we were waiting
+        if (disposed) throw new Error("Group call disposed");
+
         const userId = this.client.getUserId()!;
 
         const callFeed = new CallFeed({