return connection error message, removed mediastream during publishing

example/pubspec.lock

@@ -102,6 +102,20 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "0.6.5"
+  http:
+    dependency: transitive
+    description:
+      name: http
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.13.3"
+  http_parser:
+    dependency: transitive
+    description:
+      name: http_parser
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "4.0.0"
   livekit_client:
     dependency: "direct main"
     description:
@@ -179,6 +193,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "2.0.1"
+  pedantic:
+    dependency: transitive
+    description:
+      name: pedantic
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.11.1"
   platform:
     dependency: transitive
     description:

lib/src/participant/local_participant.dart

@@ -13,7 +13,6 @@ import 'participant.dart';
 
 class LocalParticipant extends Participant {
   RTCEngine _engine;
-  MediaStream? _mediaStream;
 
   LocalParticipant({
     required RTCEngine engine,
@@ -25,15 +24,6 @@ class LocalParticipant extends Participant {
 
   RTCEngine get engine => _engine;
 
-  Future<MediaStream> getMediaStream() async {
-    var stream = _mediaStream;
-    if (stream == null) {
-      stream = await createLocalMediaStream(sid);
-      _mediaStream = stream;
-    }
-    return stream;
-  }
-
   /// publish an audio track to the room
   Future<TrackPublication> publishAudioTrack(LocalAudioTrack track) async {
     if (audioTracks.values.any(
@@ -44,10 +34,8 @@ class LocalParticipant extends Participant {
     try {
       var trackInfo = await _engine.addTrack(
           cid: track.getCid(), name: track.name, kind: track.kind);
-      var stream = await getMediaStream();
       var transceiverInit = new RTCRtpTransceiverInit(
         direction: TransceiverDirection.SendOnly,
-        streams: [stream],
       );
       track.transceiver = await _engine.publisher?.pc.addTransceiver(
         track: track.mediaTrack,
@@ -67,7 +55,7 @@ class LocalParticipant extends Participant {
 
   /// publish a video track to the room
   Future<TrackPublication> publishVideoTrack(LocalVideoTrack track) async {
-    if (audioTracks.values.any(
+    if (videoTracks.values.any(
         (element) => element.track?.mediaTrack.id == track.mediaTrack.id)) {
       return Future.error(TrackPublishError('track already exists'));
     }
@@ -75,10 +63,8 @@ class LocalParticipant extends Participant {
     try {
       var trackInfo = await _engine.addTrack(
           cid: track.getCid(), name: track.name, kind: track.kind);
-      var stream = await getMediaStream();
       var transceiverInit = new RTCRtpTransceiverInit(
         direction: TransceiverDirection.SendOnly,
-        streams: [stream],
       );
       // TODO: video encodings and simulcast
       track.transceiver = await _engine.publisher?.pc.addTransceiver(

lib/src/rtc_engine.dart

@@ -64,14 +64,18 @@ class RTCEngine with SignalClientDelegate {
     this.client.delegate = this;
   }
 
-  Future<JoinResponse> join(String url, String token, JoinOptions? opts) {
+  Future<JoinResponse> join(String url, String token, JoinOptions? opts) async {
     this.url = url;
     this.token = token;
 
     var completer = new Completer<JoinResponse>();
     joinCompleter = completer;
 
-    client.join(url, token, opts);
+    try {
+      await client.join(url, token, opts);
+    } catch (e) {
+      return Future.error(e);
+    }
 
     // if it's not complete after 5 seconds, fail
     new Timer(connectionTimeout, () {

lib/src/signal_client.dart

@@ -1,12 +1,17 @@
+import 'dart:async';
 import 'dart:convert';
 import 'dart:developer';
 
 import 'package:flutter_webrtc/flutter_webrtc.dart';
+import 'package:livekit_client/livekit_client.dart';
 import 'package:web_socket_channel/web_socket_channel.dart';
-import './track/track.dart';
+import 'package:http/http.dart' as http;
-import './version.dart';
+
-import './proto/livekit_models.pb.dart';
+import 'logger.dart';
-import './proto/livekit_rtc.pb.dart';
+import 'track/track.dart';
+import 'version.dart';
+import 'proto/livekit_models.pb.dart';
+import 'proto/livekit_rtc.pb.dart';
 import '_websocket_api.dart'
     if (dart.library.io) '_websocket_io.dart'
     if (dart.library.html) '_websocket_html.dart' as platform;
@@ -48,22 +53,33 @@ class SignalClient {
 
   bool get connected => this._connected;
 
-  join(String url, String token, JoinOptions? options) {
+  Future<void> join(String url, String token, JoinOptions? options) async {
-    url += '/rtc';
+    var rtcUrl = '$url/rtc';
     var params = _paramsForToken(token);
     if (options != null && options.autoSubscribe != null) {
       params += '&auto_subscribe=${options.autoSubscribe! ? '1' : '0'}';
     }
-    var uri = Uri.parse(url + params);
 
-    platform.connectToWebSocket(uri).then((ws) {
+    try {
+      var ws = await platform.connectToWebSocket(Uri.parse(rtcUrl + params));
       ws.stream
           .listen(_handleMessage, onError: _handleError, onDone: _handleDone);
       _ws = ws;
-    }).catchError((error) {
+    } catch (e) {
-      // TODO: ping api endpoint
+      var completer = Completer();
-      _handleError(error);
+      var validateUri = Uri.parse('http${rtcUrl.substring(2)}/validate$params');
-    });
+      http.get(validateUri).then((response) {
+        if (response.statusCode != 200) {
+          completer.completeError(ConnectError(response.body));
+        } else {
+          completer.completeError(ConnectError());
+        }
+      }).catchError((e) {
+        completer.completeError(ConnectError());
+      });
+
+      return completer.future;
+    }
   }
 
   Future<void> reconnect(String url, String token) async {
@@ -210,7 +226,7 @@ class SignalClient {
   }
 
   _handleError(Object error) {
-    // TODO: test HTTP endpoint
+    logger.warning('received websocket error $error');
   }
 
   _handleDone() {

pubspec.lock

@@ -95,6 +95,20 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "0.6.5"
+  http:
+    dependency: "direct main"
+    description:
+      name: http
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.13.3"
+  http_parser:
+    dependency: transitive
+    description:
+      name: http_parser
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "4.0.0"
   logging:
     dependency: "direct main"
     description:
@@ -158,6 +172,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "2.0.1"
+  pedantic:
+    dependency: transitive
+    description:
+      name: pedantic
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.11.1"
   platform:
     dependency: transitive
     description:

pubspec.yaml

@@ -13,6 +13,7 @@ dependencies:
   flutter:
     sdk: flutter
   flutter_webrtc: ^0.6.4
+  http: ^0.13.3
   logging: ^1.0.1
   protobuf: ^2.0.0
   tuple: ^2.0.0