Update a call's type before notifying listeners of the change

If we notify listeners of a change in a call's type before actually making that change, the listeners will be working with glitched state. This would cause the room list to show the wrong call type in certain situations.

Author: robintown

apps/web/src/models/Call.ts

@@ -114,10 +114,9 @@ export abstract class Call extends TypedEventEmitter<CallEvent, CallEventHandler
     }
 
     protected set callType(callType: CallType) {
-        if (this._callType !== callType) {
-            this.emit(CallEvent.CallTypeChanged, callType);
-        }
+        const prevCallType = this._callType;
         this._callType = callType;
+        if (callType !== prevCallType) this.emit(CallEvent.CallTypeChanged, callType);
     }
 
     /**

apps/web/test/unit-tests/models/Call-test.ts

@@ -26,6 +26,7 @@ import {
     MatrixRTCSession,
     MatrixRTCSessionEvent,
 } from "matrix-js-sdk/src/matrixrtc";
+import { CallType } from "matrix-js-sdk/src/webrtc/call";
 
 import type { Mocked } from "jest-mock";
 import type { ClientWidgetApi } from "matrix-widget-api";
@@ -987,6 +988,35 @@ describe("ElementCall", () => {
             call.off(CallEvent.Participants, onParticipants);
         });
 
+        it("emits events when call type changes", async () => {
+            const onCallTypeChanged = jest.fn();
+            call.on(CallEvent.CallTypeChanged, onCallTypeChanged);
+            // Should default to video when unknown
+            expect(call.callType).toBe(CallType.Video);
+
+            // Change call type to voice
+            roomSession.memberships = [
+                { sender: alice.userId, deviceId: "alices_device", callIntent: "audio" } as Mocked<CallMembership>,
+            ];
+            roomSession.getConsensusCallIntent.mockReturnValue("audio");
+            roomSession.emit(MatrixRTCSessionEvent.MembershipsChanged, [], []);
+
+            expect(call.callType).toBe(CallType.Voice);
+            expect(onCallTypeChanged.mock.calls).toEqual([[CallType.Voice]]);
+
+            // Change call type back to video
+            roomSession.memberships = [
+                { sender: alice.userId, deviceId: "alices_device", callIntent: "video" } as Mocked<CallMembership>,
+            ];
+            roomSession.getConsensusCallIntent.mockReturnValue("video");
+            roomSession.emit(MatrixRTCSessionEvent.MembershipsChanged, [], []);
+
+            expect(call.callType).toBe(CallType.Video);
+            expect(onCallTypeChanged.mock.calls).toEqual([[CallType.Voice], [CallType.Video]]);
+
+            call.off(CallEvent.CallTypeChanged, onCallTypeChanged);
+        });
+
         it("ends the call immediately if the session ended", async () => {
             await connect(call, widgetApi);
             const onDestroy = jest.fn();