comments + make logic simpler to follow.

src/matrixrtc/MatrixRTCSession.ts

@@ -569,6 +569,7 @@ export class MatrixRTCSession extends TypedEventEmitter<MatrixRTCSessionEvent, M
     };
 
     public onMembershipUpdate = (): void => {
+        // This also gets called from the session manager on every relevant call.member event.
         const oldMemberships = this.memberships;
         this.memberships = MatrixRTCSession.callMembershipsForRoom(this.room);
 

src/matrixrtc/MatrixRTCSessionManager.ts

@@ -54,7 +54,7 @@ export class MatrixRTCSessionManager extends TypedEventEmitter<MatrixRTCSessionM
 
     public start(): void {
         // We shouldn't need to null-check here, but matrix-client.spec.ts mocks getRooms
-        // returing nothing, and breaks tests if you change it to return an empty array :'(
+        // returning nothing, and breaks tests if you change it to return an empty array :'(
         for (const room of this.client.getRooms() ?? []) {
             const session = MatrixRTCSession.roomSessionForRoom(this.client, room);
             if (session.memberships.length > 0) {
@@ -134,15 +134,21 @@ export class MatrixRTCSessionManager extends TypedEventEmitter<MatrixRTCSessionM
         const isNewSession = !this.roomSessions.has(room.roomId);
         const sess = this.getRoomSession(room);
 
-        const wasActiveAndKnown = sess.memberships.length > 0 && !isNewSession;
+        const wasActive = sess.memberships.length > 0;
 
         sess.onMembershipUpdate();
 
         const nowActive = sess.memberships.length > 0;
 
-        if (wasActiveAndKnown && !nowActive) {
+        const sessionStarted = !wasActive && nowActive;
+        // We do not call session Ended if the client just discovered it.
+        const sessionEnded = wasActive && !nowActive && !isNewSession;
+
+        if (sessionEnded) {
             this.emit(MatrixRTCSessionManagerEvents.SessionEnded, room.roomId, this.roomSessions.get(room.roomId)!);
-        } else if (!wasActiveAndKnown && nowActive) {
+        }
+
+        if (sessionStarted) {
             this.emit(MatrixRTCSessionManagerEvents.SessionStarted, room.roomId, this.roomSessions.get(room.roomId)!);
         }
     }

src/models/event-timeline.ts

@@ -267,7 +267,7 @@ export class EventTimeline {
     /**
      * Get a pagination token
      *
-     * @param direction -   EventTimeline.BACKWARDS to get the pagination
+     * @param direction - EventTimeline.BACKWARDS to get the pagination
      *   token for going backwards in time; EventTimeline.FORWARDS to get the
      *   pagination token for going forwards in time.
      *