Replace internal instanceof checks with typeguards (livekit#1378)

Author: lukasIO

.changeset/fair-ladybugs-divide.md

@@ -0,0 +1,5 @@
+---
+"livekit-client": patch
+---
+
+Replace internal instanceof checks with typeguards

examples/demo/demo.ts

@@ -35,7 +35,7 @@ import {
   supportsAV1,
   supportsVP9,
 } from '../../src/index';
-import { isSVCCodec } from '../../src/room/utils';
+import { isLocalParticipant, isRemoteTrack, isSVCCodec } from '../../src/room/utils';
 
 setLogLevel(LogLevel.debug);
 
@@ -165,7 +165,7 @@ const appActions = {
       .on(RoomEvent.LocalTrackPublished, (pub) => {
         const track = pub.track as LocalAudioTrack;
 
-        if (track instanceof LocalAudioTrack) {
+        if (isLocalAudioTrack(track)) {
           const { calculateVolume } = createAudioAnalyser(track);
 
           setInterval(() => {
@@ -495,7 +495,7 @@ window.appActions = appActions;
 
 function handleChatMessage(msg: ChatMessage, participant?: LocalParticipant | RemoteParticipant) {
   (<HTMLTextAreaElement>$('chat')).value +=
-    `${participant?.identity}${participant instanceof LocalParticipant ? ' (me)' : ''}: ${msg.message}\n`;
+    `${participant?.identity}${isLocalParticipant(participant) ? ' (me)' : ''}: ${msg.message}\n`;
 }
 
 function participantConnected(participant: Participant) {
@@ -596,7 +596,7 @@ function renderParticipant(participant: Participant, remove: boolean = false) {
         </div>
       </div>
       ${
-        participant instanceof RemoteParticipant
+        !isLocalParticipant(participant)
           ? `<div class="volume-control">
         <input id="volume-${identity}" type="range" min="0" max="1" step="0.1" value="1" orient="vertical" />
       </div>`
@@ -629,7 +629,7 @@ function renderParticipant(participant: Participant, remove: boolean = false) {
 
   // update properties
   container.querySelector(`#name-${identity}`)!.innerHTML = participant.identity;
-  if (participant instanceof LocalParticipant) {
+  if (isLocalParticipant(participant)) {
     container.querySelector(`#name-${identity}`)!.innerHTML += ' (you)';
   }
   const micElm = container.querySelector(`#mic-${identity}`)!;
@@ -642,7 +642,7 @@ function renderParticipant(participant: Participant, remove: boolean = false) {
     div!.classList.remove('speaking');
   }
 
-  if (participant instanceof RemoteParticipant) {
+  if (!isLocalParticipant(participant)) {
     const volumeSlider = <HTMLInputElement>container.querySelector(`#volume-${identity}`);
     volumeSlider.addEventListener('input', (ev) => {
       participant.setVolume(Number.parseFloat((ev.target as HTMLInputElement).value));
@@ -651,7 +651,7 @@ function renderParticipant(participant: Participant, remove: boolean = false) {
 
   const cameraEnabled = cameraPub && cameraPub.isSubscribed && !cameraPub.isMuted;
   if (cameraEnabled) {
-    if (participant instanceof LocalParticipant) {
+    if (isLocalParticipant(participant)) {
       // flip
       videoElm.style.transform = 'scale(-1, 1)';
     } else if (!cameraPub?.videoTrack?.attachedElements.includes(videoElm)) {
@@ -684,7 +684,7 @@ function renderParticipant(participant: Participant, remove: boolean = false) {
 
   const micEnabled = micPub && micPub.isSubscribed && !micPub.isMuted;
   if (micEnabled) {
-    if (!(participant instanceof LocalParticipant)) {
+    if (!isLocalParticipant(participant)) {
       // don't attach local audio
       audioELm.onloadeddata = () => {
         if (participant.joinedAt && participant.joinedAt.getTime() < startTime) {
@@ -787,7 +787,7 @@ function renderBitrate() {
       }
 
       if (t.source === Track.Source.Camera) {
-        if (t.videoTrack instanceof RemoteVideoTrack) {
+        if (isRemoteTrack(t.videoTrack)) {
           const codecElm = container.querySelector(`#codec-${p.identity}`)!;
           codecElm.innerHTML = t.videoTrack.getDecoderImplementation() ?? '';
         }

src/e2ee/E2eeManager.ts

@@ -7,11 +7,11 @@ import type Room from '../room/Room';
 import { ConnectionState } from '../room/Room';
 import { DeviceUnsupportedError } from '../room/errors';
 import { EngineEvent, ParticipantEvent, RoomEvent } from '../room/events';
-import LocalTrack from '../room/track/LocalTrack';
 import type RemoteTrack from '../room/track/RemoteTrack';
 import type { Track } from '../room/track/Track';
 import type { VideoCodec } from '../room/track/options';
 import { mimeTypeToVideoCodecString } from '../room/track/utils';
+import { isLocalTrack } from '../room/utils';
 import type { BaseKeyProvider } from './KeyProvider';
 import { E2EE_FLAG } from './constants';
 import { type E2EEManagerCallbacks, EncryptionEvent, KeyProviderEvent } from './events';
@@ -317,7 +317,7 @@ export class E2EEManager
   }
 
   private setupE2EESender(track: Track, sender: RTCRtpSender) {
-    if (!(track instanceof LocalTrack) || !sender) {
+    if (!isLocalTrack(track) || !sender) {
       if (!sender) log.warn('early return because sender is not ready');
       return;
     }

src/index.ts

@@ -32,7 +32,11 @@ import {
   createAudioAnalyser,
   getEmptyAudioStreamTrack,
   getEmptyVideoStreamTrack,
+  isAudioTrack,
   isBrowserSupported,
+  isLocalTrack,
+  isRemoteTrack,
+  isVideoTrack,
   supportsAV1,
   supportsAdaptiveStream,
   supportsDynacast,
@@ -100,6 +104,10 @@ export {
   supportsDynacast,
   supportsVP9,
   Mutex,
+  isAudioTrack,
+  isLocalTrack,
+  isRemoteTrack,
+  isVideoTrack,
 };
 export type {
   AudioAnalyserOptions,

src/room/RTCEngine.ts

@@ -64,7 +64,14 @@ import type { Track } from './track/Track';
 import type { TrackPublishOptions, VideoCodec } from './track/options';
 import { getTrackPublicationInfo } from './track/utils';
 import type { LoggerOptions } from './types';
-import { isVideoCodec, isWeb, sleep, supportsAddTrack, supportsTransceiver } from './utils';
+import {
+  isVideoCodec,
+  isVideoTrack,
+  isWeb,
+  sleep,
+  supportsAddTrack,
+  supportsTransceiver,
+} from './utils';
 
 const lossyDataChannel = '_lossy';
 const reliableDataChannel = '_reliable';
@@ -745,7 +752,7 @@ export default class RTCEngine extends (EventEmitter as new () => TypedEventEmit
       streams.push(track.mediaStream);
     }
 
-    if (track instanceof LocalVideoTrack) {
+    if (isVideoTrack(track)) {
       track.codec = opts.videoCodec;
     }
 

src/room/Room.ts

@@ -85,7 +85,10 @@ import {
   getEmptyAudioStreamTrack,
   isBrowserSupported,
   isCloud,
+  isLocalAudioTrack,
+  isLocalParticipant,
   isReactNative,
+  isRemotePub,
   isSafari,
   isWeb,
   supportsSetSinkId,
@@ -276,7 +279,7 @@ class Room extends (EventEmitter as new () => TypedEmitter<RoomEventCallbacks>)
       this.e2eeManager.on(
         EncryptionEvent.ParticipantEncryptionStatusChanged,
         (enabled, participant) => {
-          if (participant instanceof LocalParticipant) {
+          if (isLocalParticipant(participant)) {
             this.isE2EEEnabled = enabled;
           }
           this.emit(RoomEvent.ParticipantEncryptionStatusChanged, enabled, participant);
@@ -1950,7 +1953,7 @@ class Room extends (EventEmitter as new () => TypedEmitter<RoomEventCallbacks>)
   private updateSubscriptions() {
     for (const p of this.remoteParticipants.values()) {
       for (const pub of p.videoTrackPublications.values()) {
-        if (pub.isSubscribed && pub instanceof RemoteTrackPublication) {
+        if (pub.isSubscribed && isRemotePub(pub)) {
           pub.emitTrackUpdate();
         }
       }
@@ -2072,7 +2075,7 @@ class Room extends (EventEmitter as new () => TypedEmitter<RoomEventCallbacks>)
 
     this.emit(RoomEvent.LocalTrackPublished, pub, this.localParticipant);
 
-    if (pub.track instanceof LocalAudioTrack) {
+    if (isLocalAudioTrack(pub.track)) {
       const trackIsSilent = await pub.track.checkForSilence();
       if (trackIsSilent) {
         this.emit(RoomEvent.LocalAudioSilenceDetected, pub);

src/room/participant/LocalParticipant.ts

@@ -65,10 +65,15 @@ import type { ChatMessage, DataPublishOptions } from '../types';
 import {
   Future,
   compareVersions,
+  isAudioTrack,
   isE2EESimulcastSupported,
   isFireFox,
+  isLocalAudioTrack,
+  isLocalTrack,
+  isLocalVideoTrack,
   isSVCCodec,
   isSafari17,
+  isVideoTrack,
   isWeb,
   sleep,
   supportsAV1,
@@ -640,9 +645,9 @@ export default class LocalParticipant extends Participant {
           track.setAudioContext(this.audioContext);
         }
         track.mediaStream = stream;
-        if (track instanceof LocalAudioTrack && audioProcessor) {
+        if (isAudioTrack(track) && audioProcessor) {
           await track.setProcessor(audioProcessor);
-        } else if (track instanceof LocalVideoTrack && videoProcessor) {
+        } else if (isVideoTrack(track) && videoProcessor) {
           await track.setProcessor(videoProcessor);
         }
         return track;
@@ -717,15 +722,15 @@ export default class LocalParticipant extends Participant {
     options?: TrackPublishOptions,
     isRepublish = false,
   ): Promise<LocalTrackPublication> {
-    if (track instanceof LocalAudioTrack) {
+    if (isLocalAudioTrack(track)) {
       track.setAudioContext(this.audioContext);
     }
 
     await this.reconnectFuture?.promise;
     if (this.republishPromise && !isRepublish) {
       await this.republishPromise;
     }
-    if (track instanceof LocalTrack && this.pendingPublishPromises.has(track)) {
+    if (isLocalTrack(track) && this.pendingPublishPromises.has(track)) {
       await this.pendingPublishPromises.get(track);
     }
     let defaultConstraints: MediaTrackConstraints | undefined;
@@ -857,15 +862,15 @@ export default class LocalParticipant extends Participant {
 
   private async publish(track: LocalTrack, opts: TrackPublishOptions, isStereo: boolean) {
     const existingTrackOfSource = Array.from(this.trackPublications.values()).find(
-      (publishedTrack) => track instanceof LocalTrack && publishedTrack.source === track.source,
+      (publishedTrack) => isLocalTrack(track) && publishedTrack.source === track.source,
     );
     if (existingTrackOfSource && track.source !== Track.Source.Unknown) {
       this.log.info(`publishing a second track with the same source: ${track.source}`, {
         ...this.logContext,
         ...getLogContextFromTrack(track),
       });
     }
-    if (opts.stopMicTrackOnMute && track instanceof LocalAudioTrack) {
+    if (opts.stopMicTrackOnMute && isAudioTrack(track)) {
       track.stopOnMute = true;
     }
 
@@ -950,7 +955,7 @@ export default class LocalParticipant extends Participant {
       req.width = dims.width;
       req.height = dims.height;
       // for svc codecs, disable simulcast and use vp8 for backup codec
-      if (track instanceof LocalVideoTrack) {
+      if (isLocalVideoTrack(track)) {
         if (isSVCCodec(videoCodec)) {
           if (track.source === Track.Source.ScreenShare) {
             // vp9 svc with screenshare cannot encode multiple spatial layers
@@ -1036,7 +1041,7 @@ export default class LocalParticipant extends Participant {
 
       track.sender = await this.engine.createSender(track, opts, encodings);
 
-      if (track instanceof LocalVideoTrack) {
+      if (isLocalVideoTrack(track)) {
         opts.degradationPreference ??= getDefaultDegradationPreference(track);
         track.setDegradationPreference(opts.degradationPreference);
       }
@@ -1126,9 +1131,9 @@ export default class LocalParticipant extends Participant {
       trackInfo: ti,
     });
 
-    if (track instanceof LocalVideoTrack) {
+    if (isLocalVideoTrack(track)) {
       track.startMonitor(this.engine.client);
-    } else if (track instanceof LocalAudioTrack) {
+    } else if (isLocalAudioTrack(track)) {
       track.startMonitor();
     }
 
@@ -1169,7 +1174,7 @@ export default class LocalParticipant extends Participant {
       throw new TrackInvalidError('track is not published');
     }
 
-    if (!(track instanceof LocalVideoTrack)) {
+    if (!isLocalVideoTrack(track)) {
       throw new TrackInvalidError('track is not a video track');
     }
 
@@ -1236,7 +1241,7 @@ export default class LocalParticipant extends Participant {
     track: LocalTrack | MediaStreamTrack,
     stopOnUnpublish?: boolean,
   ): Promise<LocalTrackPublication | undefined> {
-    if (track instanceof LocalTrack) {
+    if (isLocalTrack(track)) {
       const publishPromise = this.pendingPublishPromises.get(track);
       if (publishPromise) {
         this.log.info('awaiting publish promise before attempting to unpublish', {
@@ -1303,7 +1308,7 @@ export default class LocalParticipant extends Participant {
         if (this.engine.removeTrack(trackSender)) {
           negotiationNeeded = true;
         }
-        if (track instanceof LocalVideoTrack) {
+        if (isLocalVideoTrack(track)) {
           for (const [, trackInfo] of track.simulcastCodecs) {
             if (trackInfo.sender) {
               if (this.engine.removeTrack(trackInfo.sender)) {
@@ -1349,9 +1354,7 @@ export default class LocalParticipant extends Participant {
     tracks: LocalTrack[] | MediaStreamTrack[],
   ): Promise<LocalTrackPublication[]> {
     const results = await Promise.all(tracks.map((track) => this.unpublishTrack(track)));
-    return results.filter(
-      (track) => track instanceof LocalTrackPublication,
-    ) as LocalTrackPublication[];
+    return results.filter((track) => !!track);
   }
 
   async republishAllTracks(options?: TrackPublishOptions, restartTracks: boolean = true) {
@@ -1379,7 +1382,7 @@ export default class LocalParticipant extends Participant {
               !track.isMuted &&
               track.source !== Track.Source.ScreenShare &&
               track.source !== Track.Source.ScreenShareAudio &&
-              (track instanceof LocalAudioTrack || track instanceof LocalVideoTrack) &&
+              (isLocalAudioTrack(track) || isLocalVideoTrack(track)) &&
               !track.isUserProvided
             ) {
               // generally we need to restart the track before publishing, often a full reconnect
@@ -1962,7 +1965,7 @@ export default class LocalParticipant extends Participant {
       this.unpublishTrack(track);
     } else if (track.isUserProvided) {
       await track.mute();
-    } else if (track instanceof LocalAudioTrack || track instanceof LocalVideoTrack) {
+    } else if (isLocalAudioTrack(track) || isLocalVideoTrack(track)) {
       try {
         if (isWeb()) {
           try {
@@ -1997,7 +2000,7 @@ export default class LocalParticipant extends Participant {
             ...this.logContext,
             ...getLogContextFromTrack(track),
           });
-          if (track instanceof LocalAudioTrack) {
+          if (isLocalAudioTrack(track)) {
             // fall back to default device if available
             await track.restartTrack({ deviceId: 'default' });
           } else {
@@ -2026,7 +2029,7 @@ export default class LocalParticipant extends Participant {
 
       // this looks overly complicated due to this object tree
       if (track instanceof MediaStreamTrack) {
-        if (localTrack instanceof LocalAudioTrack || localTrack instanceof LocalVideoTrack) {
+        if (isLocalAudioTrack(localTrack) || isLocalVideoTrack(localTrack)) {
           if (localTrack.mediaStreamTrack === track) {
             publication = <LocalTrackPublication>pub;
           }

src/room/participant/Participant.ts

@@ -11,15 +11,14 @@ import { EventEmitter } from 'events';
 import type TypedEmitter from 'typed-emitter';
 import log, { LoggerNames, type StructuredLogger, getLogger } from '../../logger';
 import { ParticipantEvent, TrackEvent } from '../events';
-import LocalAudioTrack from '../track/LocalAudioTrack';
 import type LocalTrackPublication from '../track/LocalTrackPublication';
-import RemoteAudioTrack from '../track/RemoteAudioTrack';
 import type RemoteTrack from '../track/RemoteTrack';
 import type RemoteTrackPublication from '../track/RemoteTrackPublication';
 import { Track } from '../track/Track';
 import type { TrackPublication } from '../track/TrackPublication';
 import { diffAttributes } from '../track/utils';
 import type { ChatMessage, LoggerOptions, TranscriptionSegment } from '../types';
+import { isAudioTrack } from '../utils';
 
 export enum ConnectionQuality {
   Excellent = 'excellent',
@@ -317,9 +316,7 @@ export default class Participant extends (EventEmitter as new () => TypedEmitter
   setAudioContext(ctx: AudioContext | undefined) {
     this.audioContext = ctx;
     this.audioTrackPublications.forEach(
-      (track) =>
-        (track.track instanceof RemoteAudioTrack || track.track instanceof LocalAudioTrack) &&
-        track.track.setAudioContext(ctx),
+      (track) => isAudioTrack(track.track) && track.track.setAudioContext(ctx),
     );
   }