events: refactor native event handling

Add listeners for the native events early, so they are setup by the time
we need them, since they are added asynchronously.

Then use a JS event emitter for re-emitting them.

ios/RCTWebRTC/WebRTCModule.h

@@ -30,7 +30,6 @@ static NSString *const kEventPeerConnectionDidOpenDataChannel = @"peerConnection
 static NSString *const kEventDataChannelStateChanged = @"dataChannelStateChanged";
 static NSString *const kEventDataChannelReceiveMessage = @"dataChannelReceiveMessage";
 static NSString *const kEventMediaStreamTrackMuteChanged = @"mediaStreamTrackMuteChanged";
-static NSString *const kEventTransceiverOnError = @"transceiverOnError";
 static NSString *const kEventPeerConnectionOnRemoveTrack = @"peerConnectionOnRemoveTrack";
 static NSString *const kEventPeerConnectionOnTrack = @"peerConnectionOnTrack";
 

ios/RCTWebRTC/WebRTCModule.m

@@ -113,7 +113,6 @@ - (dispatch_queue_t)methodQueue
     kEventDataChannelStateChanged,
     kEventDataChannelReceiveMessage,
     kEventMediaStreamTrackMuteChanged,
-    kEventTransceiverOnError,
     kEventPeerConnectionOnRemoveTrack,
     kEventPeerConnectionOnTrack
   ];

src/EventEmitter.ts

@@ -1,22 +1,56 @@
 import { NativeModules, NativeEventEmitter, EmitterSubscription } from 'react-native';
+// @ts-ignore
+import EventEmitter from 'react-native/Libraries/vendor/emitter/EventEmitter';
 
 const { WebRTCModule } = NativeModules;
 
-const EventEmitter = new NativeEventEmitter(WebRTCModule);
-
-export default EventEmitter;
+// This emitter is going to be used to listen to all the native events (once) and then
+// re-emit them on a JS-only emitter.
+const nativeEmitter = new NativeEventEmitter(WebRTCModule);
+
+const NATIVE_EVENTS = [
+    'peerConnectionSignalingStateChanged',
+    'peerConnectionStateChanged',
+    'peerConnectionOnRenegotiationNeeded',
+    'peerConnectionIceConnectionChanged',
+    'peerConnectionIceGatheringChanged',
+    'peerConnectionGotICECandidate',
+    'peerConnectionDidOpenDataChannel',
+    'peerConnectionOnRemoveTrack',
+    'peerConnectionOnTrack',
+    'dataChannelStateChanged',
+    'dataChannelReceiveMessage',
+    'mediaStreamTrackMuteChanged',
+];
+
+const eventEmitter = new EventEmitter();
+
+// TODO: migrate RTCDataChannel to the new API and stop exporting this.
+export default eventEmitter;
+
+export function setupNativeEvents() {
+    for (const eventName of NATIVE_EVENTS) {
+        nativeEmitter.addListener(eventName, (...args) => {
+            eventEmitter.emit(eventName, ...args);
+        });
+    }
+}
 
 type EventHandler = (event: unknown) => void;
 type Listener = unknown;
 
 const _subscriptions: Map<Listener, EmitterSubscription[]> = new Map();
 
 export function addListener(listener: Listener, eventName: string, eventHandler: EventHandler): void {
+    if (!NATIVE_EVENTS.includes(eventName)) {
+        throw new Error(`Invalid event: ${eventName}`);
+    }
+
     if (!_subscriptions.has(listener)) {
         _subscriptions.set(listener, []);
     }
 
-    _subscriptions.get(listener)?.push(EventEmitter.addListener(eventName, eventHandler));
+    _subscriptions.get(listener)?.push(eventEmitter.addListener(eventName, eventHandler));
 }
 
 export function removeListener(listener: Listener): void {

src/index.ts

@@ -1,3 +1,4 @@
+import { setupNativeEvents } from './EventEmitter';
 import Logger from './Logger';
 import mediaDevices from './MediaDevices';
 import MediaStream from './MediaStream';
@@ -17,6 +18,9 @@ import ScreenCapturePickerView from './ScreenCapturePickerView';
 Logger.enable('*');
 // Logger.enable(`*,-${Logger.ROOT_PREFIX}:*:DEBUG`);
 
+// Add listeners for the native events early, since they are added asynchronously.
+setupNativeEvents();
+
 export {
     RTCIceCandidate,
     RTCPeerConnection,