fix video track lost for migration on safari (#419)

* don't detach track when same mediatrack received

* changeset

* attempt

Co-authored-by: David Zhao <[email protected]>

Author: cnderrauber

.changeset/six-insects-enjoy.md

@@ -0,0 +1,5 @@
+---
+'livekit-client': patch
+---
+
+fix video track lost for safari migration

src/room/track/RemoteTrackPublication.ts

@@ -129,29 +129,26 @@ export default class RemoteTrackPublication extends TrackPublication {
   setTrack(track?: RemoteTrack) {
     const prevStatus = this.subscriptionStatus;
     const prevTrack = this.track;
+    if (prevTrack === track) {
+      return;
+    }
     if (prevTrack) {
       // unregister listener
       prevTrack.off(TrackEvent.VideoDimensionsChanged, this.handleVideoDimensionsChange);
       prevTrack.off(TrackEvent.VisibilityChanged, this.handleVisibilityChange);
       prevTrack.off(TrackEvent.Ended, this.handleEnded);
       prevTrack.detach();
+      this.emit(TrackEvent.Unsubscribed, prevTrack);
     }
     super.setTrack(track);
     if (track) {
       track.sid = this.trackSid;
       track.on(TrackEvent.VideoDimensionsChanged, this.handleVideoDimensionsChange);
       track.on(TrackEvent.VisibilityChanged, this.handleVisibilityChange);
       track.on(TrackEvent.Ended, this.handleEnded);
+      this.emit(TrackEvent.Subscribed, track);
     }
     this.emitSubscriptionUpdateIfChanged(prevStatus);
-    if (!!track !== !!prevTrack) {
-      // when undefined status changes, there's a subscription changed event
-      if (track) {
-        this.emit(TrackEvent.Subscribed, track);
-      } else if (prevTrack) {
-        this.emit(TrackEvent.Unsubscribed, prevTrack);
-      }
-    }
   }
 
   /** @internal */