add participant id when resuming (#425)

* changeset

* prettier

.changeset/slow-chefs-yawn.md

@@ -0,0 +1,5 @@
+---
+'livekit-client': patch
+---
+
+add participant id when reconnecting

src/api/SignalClient.ts

@@ -38,6 +38,9 @@ interface ConnectOpts {
   /** internal */
   reconnect?: boolean;
 
+  /** internal */
+  sid?: string;
+
   /** @deprecated */
   publishOnly?: string;
 
@@ -161,12 +164,13 @@ export class SignalClient {
     return res as JoinResponse;
   }
 
-  async reconnect(url: string, token: string): Promise<void> {
+  async reconnect(url: string, token: string, sid?: string): Promise<void> {
     this.isReconnecting = true;
     // clear ping interval and restart it once reconnected
     this.clearPingInterval();
     await this.connect(url, token, {
       reconnect: true,
+      sid,
     });
   }
 
@@ -607,6 +611,9 @@ function createConnectionParams(token: string, info: ClientInfo, opts?: ConnectO
   // opts
   if (opts?.reconnect) {
     params.set('reconnect', '1');
+    if (opts?.sid) {
+      params.set('sid', opts.sid);
+    }
   }
   if (opts?.autoSubscribe !== undefined) {
     params.set('auto_subscribe', opts.autoSubscribe ? '1' : '0');

src/room/RTCEngine.ts

@@ -120,6 +120,8 @@ export default class RTCEngine extends (EventEmitter as new () => TypedEventEmit
 
   private reconnectTimeout?: ReturnType<typeof setTimeout>;
 
+  private participantSid?: string;
+
   constructor(private options: RoomOptions) {
     super();
     this.client = new SignalClient();
@@ -237,6 +239,8 @@ export default class RTCEngine extends (EventEmitter as new () => TypedEventEmit
       return;
     }
 
+    this.participantSid = joinResponse.participant?.sid;
+
     // update ICE servers before creating PeerConnection
     if (joinResponse.iceServers && !this.rtcConfig.iceServers) {
       const rtcIceServers: RTCIceServer[] = [];
@@ -798,7 +802,7 @@ export default class RTCEngine extends (EventEmitter as new () => TypedEventEmit
     }
 
     try {
-      await this.client.reconnect(this.url, this.token);
+      await this.client.reconnect(this.url, this.token, this.participantSid);
     } catch (e) {
       let message = '';
       if (e instanceof Error) {