fix: ensure tracks are stopped when disposing a Publisher (#1676)

In some circumstances, we were dangling track clones. No data flowed to
the SFU, but the browser kept the camera/mic indicators on as there were
MediaStreamTrack instances that weren't stopped properly.

### Implementation notes

Upon disposing of a `Publisher`, we now iterate through all transceivers
and we explicitly stop the assigned track.
This PR also fixes another issue that could lead to dangling, unstopped
tracks when replacing a track on an existing transceiver.

Author: oliverlaz

packages/client/src/rtc/BasePeerConnection.ts

@@ -75,12 +75,12 @@ export abstract class BasePeerConnection {
   /**
    * Disposes the `RTCPeerConnection` instance.
    */
-  dispose = () => {
+  dispose() {
     this.onUnrecoverableError = undefined;
     this.isDisposed = true;
     this.detachEventHandlers();
     this.pc.close();
-  };
+  }
 
   /**
    * Detaches the event handlers from the `RTCPeerConnection`.

packages/client/src/rtc/Publisher.ts

@@ -73,6 +73,14 @@ export class Publisher extends BasePeerConnection {
     withCancellation('publisher.negotiate', () => Promise.resolve());
   }
 
+  /**
+   * Disposes this Publisher instance.
+   */
+  dispose() {
+    super.dispose();
+    this.stopAllTracks();
+  }
+
   /**
    * Starts publishing the given track of the given media stream.
    *
@@ -98,7 +106,9 @@ export class Publisher extends BasePeerConnection {
       if (!transceiver) {
         this.addTransceiver(trackToPublish, publishOption);
       } else {
+        const previousTrack = transceiver.sender.track;
         await transceiver.sender.replaceTrack(trackToPublish);
+        previousTrack?.stop();
       }
     }
   };
@@ -203,6 +213,15 @@ export class Publisher extends BasePeerConnection {
     }
   };
 
+  /**
+   * Stops all the cloned tracks that are being published to the SFU.
+   */
+  stopAllTracks = () => {
+    for (const { transceiver } of this.transceiverCache.items()) {
+      transceiver.sender.track?.stop();
+    }
+  };
+
   private changePublishQuality = async (videoSender: VideoSender) => {
     const { trackType, layers, publishOptionId } = videoSender;
     const enabledLayers = layers.filter((l) => l.active);

packages/client/src/rtc/__tests__/Publisher.test.ts

@@ -124,6 +124,8 @@ describe('Publisher', () => {
       vi.spyOn(track, 'clone').mockReturnValue(clone);
 
       const transceiver = new RTCRtpTransceiver();
+      // @ts-ignore test setup
+      transceiver.sender.track = track;
       publisher['transceiverCache'].add(
         publisher['publishOptions'][0],
         transceiver,
@@ -134,6 +136,7 @@ describe('Publisher', () => {
       expect(track.clone).toHaveBeenCalled();
       expect(publisher['pc'].addTransceiver).not.toHaveBeenCalled();
       expect(transceiver.sender.replaceTrack).toHaveBeenCalledWith(clone);
+      expect(track.stop).toHaveBeenCalled();
     });
   });
 
@@ -701,5 +704,12 @@ describe('Publisher', () => {
       publisher.stopTracks(TrackType.VIDEO);
       expect(track!.stop).toHaveBeenCalled();
     });
+
+    it('stopAllTracks should stop all tracks', () => {
+      const track = cache['cache'][0].transceiver.sender.track;
+      vi.spyOn(track, 'stop');
+      publisher.stopAllTracks();
+      expect(track!.stop).toHaveBeenCalled();
+    });
   });
 });

packages/client/src/rtc/__tests__/mocks/webrtc.mocks.ts

@@ -6,7 +6,7 @@ const RTCPeerConnectionMock = vi.fn((): Partial<RTCPeerConnection> => {
     addIceCandidate: vi.fn(),
     removeEventListener: vi.fn(),
     getTransceivers: vi.fn(),
-    addTransceiver: vi.fn(),
+    addTransceiver: vi.fn().mockReturnValue(new RTCRtpTransceiverMock()),
     getConfiguration: vi.fn(),
     setConfiguration: vi.fn(),
     createOffer: vi.fn().mockResolvedValue({}),

sample-apps/client/ts-quickstart/package.json

@@ -9,8 +9,7 @@
     "preview": "vite preview"
   },
   "dependencies": {
-    "@stream-io/video-client": "workspace:^",
-    "js-base64": "^3.7.5"
+    "@stream-io/video-client": "workspace:^"
   },
   "devDependencies": {
     "@vitejs/plugin-basic-ssl": "^1.0.1",

sample-apps/client/ts-quickstart/src/controls.ts

@@ -1,4 +1,4 @@
-import { Call } from '@stream-io/video-client';
+import { Call, CallingState } from '@stream-io/video-client';
 
 const renderAudioButton = (call: Call) => {
   const audioButton = document.createElement('button');
@@ -59,12 +59,33 @@ const renderFlipButton = (call: Call) => {
 
   return flipButton;
 };
+const renderLeaveJoinButton = (call: Call) => {
+  const btn = document.createElement('button');
+  btn.addEventListener('click', () => {
+    if (call.state.callingState === CallingState.LEFT) {
+      call.join();
+    } else {
+      call.leave();
+    }
+  });
+
+  call.state.callingState$.subscribe((s) => {
+    if (s !== CallingState.JOINED) {
+      btn.innerText = 'Join';
+    } else {
+      btn.innerText = 'Leave';
+    }
+  });
+
+  return btn;
+};
 
 export const renderControls = (call: Call) => {
   return {
     audioButton: renderAudioButton(call),
     videoButton: renderVideoButton(call),
     screenShareButton: renderScreenShareButton(call),
     flipButton: renderFlipButton(call),
+    leaveJoinCallButton: renderLeaveJoinButton(call),
   };
 };

sample-apps/client/ts-quickstart/src/main.ts

@@ -1,6 +1,5 @@
 import './style.css';
-import { StreamVideoClient, User } from '@stream-io/video-client';
-import { decode } from 'js-base64';
+import { CallingState, StreamVideoClient } from '@stream-io/video-client';
 import { cleanupParticipant, renderParticipant } from './participant';
 import { renderControls } from './controls';
 import {
@@ -12,33 +11,29 @@ import {
 import { isMobile } from './mobile';
 import { ClosedCaptionManager } from './closed-captions';
 
-const searchParams = new URLSearchParams(window.location.search);
-const extractPayloadFromToken = (token: string) => {
-  const [, payload] = token.split('.');
-
-  if (!payload) throw new Error('Malformed token, missing payload');
-
-  return (JSON.parse(decode(payload)) ?? {}) as Record<string, unknown>;
-};
-
-const apiKey = import.meta.env.VITE_STREAM_API_KEY;
-const token = searchParams.get('ut') ?? import.meta.env.VITE_STREAM_USER_TOKEN;
-const user: User = {
-  id: extractPayloadFromToken(token)['user_id'] as string,
-};
+const ENVIRONMENT = 'demo';
+const userId = 'luke';
+const credentials = (await fetch(
+  `https://pronto.getstream.io/api/auth/create-token?environment=${ENVIRONMENT}&user_id=${userId}`,
+).then((res) => res.json())) as { apiKey: string; token: string };
 
+const searchParams = new URLSearchParams(window.location.search);
 const callId =
   searchParams.get('call_id') ||
   import.meta.env.VITE_STREAM_CALL_ID ||
   (new Date().getTime() + Math.round(Math.random() * 100)).toString();
 
 const client = new StreamVideoClient({
-  apiKey,
-  token,
-  user,
-  options: { logLevel: import.meta.env.VITE_STREAM_LOG_LEVEL },
+  apiKey: credentials.apiKey,
+  token: credentials.token,
+  user: { id: userId, name: 'Luke' },
+  options: { logLevel: 'debug' },
 });
+
 const call = client.call('default', callId);
+await call.camera.enable();
+await call.microphone.disableSpeakingWhileMutedNotification();
+await call.microphone.enable();
 
 // @ts-ignore
 window.call = call;
@@ -55,6 +50,7 @@ const container = document.getElementById('call-controls')!;
 
 // render mic and camera controls
 const controls = renderControls(call);
+container.appendChild(controls.leaveJoinCallButton);
 container.appendChild(controls.audioButton);
 container.appendChild(controls.videoButton);
 container.appendChild(controls.screenShareButton);
@@ -95,6 +91,8 @@ const parentContainer = document.getElementById('participants')!;
 call.setViewport(parentContainer);
 
 call.state.participants$.subscribe((participants) => {
+  if (call.state.callingState === CallingState.LEFT) return;
+
   // render / update existing participants
   participants.forEach((participant) => {
     renderParticipant(call, participant, parentContainer, screenShareContainer);

sample-apps/client/ts-quickstart/vite.config.ts

@@ -2,4 +2,7 @@ import basicSsl from '@vitejs/plugin-basic-ssl';
 
 export default {
   plugins: [basicSsl()],
+  build: {
+    target: 'esnext',
+  },
 };

yarn.lock

@@ -8212,7 +8212,6 @@ __metadata:
   dependencies:
     "@stream-io/video-client": "workspace:^"
     "@vitejs/plugin-basic-ssl": ^1.0.1
-    js-base64: ^3.7.5
     typescript: ^5.5.2
     vite: ^5.4.6
   languageName: unknown