Handle signal disconnect during reconnect

src/api/SignalClient.ts

@@ -386,7 +386,11 @@ export class SignalClient {
             reject(new ConnectionError('Websocket got closed during a (re)connection attempt'));
           }
 
-          this.log.warn(`websocket closed`, { ...this.logContext, reason: ev.reason });
+          this.log.warn(`websocket closed`, {
+            ...this.logContext,
+            reason: ev.reason,
+            state: this.state,
+          });
           this.handleOnClose(ev.reason);
         };
       } finally {

src/proto/livekit_rtc_pb.ts

@@ -2084,6 +2084,14 @@ export class SimulateScenario extends Message<SimulateScenario> {
      */
     value: bigint;
     case: "subscriberBandwidth";
+  } | {
+    /**
+     * disconnect signal on resume
+     *
+     * @generated from field: bool disconnect_signal_on_resume = 7;
+     */
+    value: boolean;
+    case: "disconnectSignalOnResume";
   } | { case: undefined; value?: undefined } = { case: undefined };
 
   constructor(data?: PartialMessage<SimulateScenario>) {
@@ -2100,6 +2108,7 @@ export class SimulateScenario extends Message<SimulateScenario> {
     { no: 4, name: "server_leave", kind: "scalar", T: 8 /* ScalarType.BOOL */, oneof: "scenario" },
     { no: 5, name: "switch_candidate_protocol", kind: "enum", T: proto3.getEnumType(CandidateProtocol), oneof: "scenario" },
     { no: 6, name: "subscriber_bandwidth", kind: "scalar", T: 3 /* ScalarType.INT64 */, oneof: "scenario" },
+    { no: 7, name: "disconnect_signal_on_resume", kind: "scalar", T: 8 /* ScalarType.BOOL */, oneof: "scenario" },
   ]);
 
   static fromBinary(bytes: Uint8Array, options?: Partial<BinaryReadOptions>): SimulateScenario {

src/room/RTCEngine.ts

@@ -845,6 +845,7 @@ export default class RTCEngine extends (EventEmitter as new () => TypedEventEmit
     }
     // guard for attempting reconnection multiple times while one attempt is still not finished
     if (this.attemptingReconnect) {
+      log.warn('already attempting reconnect, returning early', this.logContext);
       return;
     }
     if (
@@ -948,6 +949,12 @@ export default class RTCEngine extends (EventEmitter as new () => TypedEventEmit
       this.emit(EngineEvent.SignalRestarted, joinResponse);
 
       await this.waitForPCReconnected();
+
+      // re-check signal connection state before setting engine as resumed
+      if (this.client.currentState !== SignalConnectionState.CONNECTED) {
+        throw new SignalReconnectError('Signal connection got severed during reconnect');
+      }
+
       this.regionUrlProvider?.resetAttempts();
       // reconnect success
       this.emit(EngineEvent.Restarted);
@@ -1005,6 +1012,12 @@ export default class RTCEngine extends (EventEmitter as new () => TypedEventEmit
     await this.pcManager.triggerIceRestart();
 
     await this.waitForPCReconnected();
+
+    // re-check signal connection state before setting engine as resumed
+    if (this.client.currentState !== SignalConnectionState.CONNECTED) {
+      throw new SignalReconnectError('Signal connection got severed during reconnect');
+    }
+
     this.client.setReconnected();
 
     // recreate publish datachannel if it's id is null

src/room/Room.ts

@@ -788,10 +788,21 @@ class Room extends (EventEmitter as new () => TypedEmitter<RoomEventCallbacks>)
         // @ts-expect-error function is private
         await this.engine.client.handleOnClose('simulate resume-disconnect');
         break;
+      case 'disconnect-signal-on-resume':
+        postAction = async () => {
+          // @ts-expect-error function is private
+          await this.engine.client.handleOnClose('simulate resume-disconnect');
+        };
+        req = new SimulateScenario({
+          scenario: {
+            case: 'disconnectSignalOnResume',
+            value: true,
+          },
+        });
+        break;
       case 'full-reconnect':
         this.engine.fullReconnectOnNext = true;
-        // @ts-expect-error function is private
-        await this.engine.client.handleOnClose('simulate full-reconnect');
+
         break;
       case 'force-tcp':
       case 'force-tls':
@@ -824,11 +835,12 @@ class Room extends (EventEmitter as new () => TypedEmitter<RoomEventCallbacks>)
           },
         });
         break;
+
       default:
     }
     if (req) {
-      this.engine.client.sendSimulateScenario(req);
-      postAction();
+      await this.engine.client.sendSimulateScenario(req);
+      await postAction();
     }
   }
 
@@ -1669,6 +1681,10 @@ class Room extends (EventEmitter as new () => TypedEmitter<RoomEventCallbacks>)
         this.log.warn('detected connection state mismatch', {
           ...this.logContext,
           numFailures: consecutiveFailures,
+          engine: {
+            closed: this.engine.isClosed,
+            transportsConnected: this.engine.verifyTransport(),
+          },
         });
         if (consecutiveFailures >= 3) {
           this.recreateEngine();
@@ -1820,7 +1836,7 @@ class Room extends (EventEmitter as new () => TypedEmitter<RoomEventCallbacks>)
                 await window.navigator.mediaDevices.getUserMedia({ video: true })
               ).getVideoTracks()[0]
             : createDummyVideoStreamTrack(
-                160 * participantOptions.aspectRatios[0] ?? 1,
+                160 * (participantOptions.aspectRatios[0] ?? 1),
                 160,
                 true,
                 true,
@@ -1870,7 +1886,7 @@ class Room extends (EventEmitter as new () => TypedEmitter<RoomEventCallbacks>)
       const p = this.getOrCreateParticipant(info.identity, info);
       if (participantOptions.video) {
         const dummyVideo = createDummyVideoStreamTrack(
-          160 * participantOptions.aspectRatios[i % participantOptions.aspectRatios.length] ?? 1,
+          160 * (participantOptions.aspectRatios[i % participantOptions.aspectRatios.length] ?? 1),
           160,
           false,
           true,

src/room/types.ts

@@ -47,7 +47,8 @@ export type SimulationScenario =
   // overrides server-side bandwidth estimator with set bandwidth
   // this can be used to test application behavior when congested or
   // to disable congestion control entirely (by setting bandwidth to 100Mbps)
-  | 'subscriber-bandwidth';
+  | 'subscriber-bandwidth'
+  | 'disconnect-signal-on-resume';
 
 export type LoggerOptions = {
   loggerName?: string;