Await for a successful connection to the websocket before listening t…

…o messages (#76)

* Await for a successful connection to the websocket before listening to messages

* Fix socket reconnection

* Update socket state accordingly and reason about at the beginning of _connect()

lib/src/socket.dart

@@ -171,10 +171,13 @@ class PhoenixSocket {
   bool get isConnected => _ws != null && _socketState == SocketState.connected;
 
   void _connect(Completer<PhoenixSocket?> completer) async {
-    if (_ws != null) {
+    if (_ws != null &&
+        (_socketState == SocketState.connected ||
+            _socketState == SocketState.connecting)) {
       _logger.warning(
           'Calling connect() on already connected or connecting socket.');
       completer.complete(this);
+      return;
     }
 
     _shouldReconnect = true;
@@ -190,6 +193,7 @@ class PhoenixSocket {
       _ws = _webSocketChannelFactory != null
           ? _webSocketChannelFactory!(_mountPoint)
           : WebSocketChannel.connect(_mountPoint);
+
       _ws!.stream
           .where(_shouldPipeMessage)
           .listen(_onSocketData, cancelOnError: true)
@@ -203,7 +207,13 @@ class PhoenixSocket {
     _socketState = SocketState.connecting;
 
     try {
+      // Wait for the WebSocket to be ready before continuing. In case of a
+      // failure to connect, the future will complete with an error and will be
+      // caught.
+      await _ws!.ready;
+
       _socketState = SocketState.connected;
+
       _logger.finest('Waiting for initial heartbeat roundtrip');
       if (await _sendHeartbeat(ignorePreviousHeartbeat: true)) {
         _stateStreamController.add(PhoenixSocketOpenEvent());
@@ -508,10 +518,6 @@ class PhoenixSocket {
   void _onSocketData(message) => onSocketDataCallback(message);
 
   void _onSocketError(dynamic error, dynamic stacktrace) {
-    if (_socketState == SocketState.closing ||
-        _socketState == SocketState.closed) {
-      return;
-    }
     final socketError = PhoenixSocketErrorEvent(
       error: error,
       stacktrace: stacktrace,