Optimized exception handling and awaits.

Frameworks/MQTTnet.NetFramework/Implementations/MqttWebSocketChannel.cs

@@ -1,6 +1,5 @@
 using MQTTnet.Core.Channel;
 using MQTTnet.Core.Client;
-using MQTTnet.Core.Exceptions;
 using System;
 using System.IO;
 using System.Net.WebSockets;
@@ -11,7 +10,7 @@ namespace MQTTnet.Implementations
 {
     public sealed class MqttWebSocketChannel : IMqttCommunicationChannel, IDisposable
     {
-        private ClientWebSocket _webSocket = new ClientWebSocket();
+        private ClientWebSocket _webSocket;
 
         public Stream RawStream { get; private set; }
         public Stream SendStream => RawStream;
@@ -19,25 +18,15 @@ namespace MQTTnet.Implementations
 
         public async Task ConnectAsync(MqttClientOptions options)
         {
-            _webSocket = null;
-
-            try
-            {
-                _webSocket = new ClientWebSocket();
-                await _webSocket.ConnectAsync(new Uri(options.Server), CancellationToken.None);
-
-                RawStream = new WebSocketStream(_webSocket);
-            }
-            catch (WebSocketException exception)
-            {
-                throw new MqttCommunicationException(exception);
-            }
+            _webSocket = new ClientWebSocket();
+            await _webSocket.ConnectAsync(new Uri(options.Server), CancellationToken.None);
+            RawStream = new WebSocketStream(_webSocket);
         }
 
         public Task DisconnectAsync()
         {
             RawStream = null;
-            return _webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, string.Empty, CancellationToken.None);
+            return _webSocket?.CloseAsync(WebSocketCloseStatus.NormalClosure, string.Empty, CancellationToken.None);
         }
 
         public void Dispose()

Frameworks/MQTTnet.NetStandard/Implementations/MqttWebSocketChannel.cs

@@ -1,6 +1,5 @@
 using MQTTnet.Core.Channel;
 using MQTTnet.Core.Client;
-using MQTTnet.Core.Exceptions;
 using System;
 using System.IO;
 using System.Net.WebSockets;
@@ -11,7 +10,7 @@ namespace MQTTnet.Implementations
 {
     public sealed class MqttWebSocketChannel : IMqttCommunicationChannel, IDisposable
     {
-        private ClientWebSocket _webSocket = new ClientWebSocket();
+        private ClientWebSocket _webSocket;
 
         public Stream SendStream => RawStream;
         public Stream ReceiveStream => RawStream;
@@ -19,25 +18,15 @@ namespace MQTTnet.Implementations
 
         public async Task ConnectAsync(MqttClientOptions options)
         {
-            _webSocket = null;
-
-            try
-            {
-                _webSocket = new ClientWebSocket();
-                await _webSocket.ConnectAsync(new Uri(options.Server), CancellationToken.None);
-
-                RawStream = new WebSocketStream(_webSocket);
-            }
-            catch (WebSocketException exception)
-            {
-                throw new MqttCommunicationException(exception);
-            }
+            _webSocket = new ClientWebSocket();
+            await _webSocket.ConnectAsync(new Uri(options.Server), CancellationToken.None);
+            RawStream = new WebSocketStream(_webSocket);
         }
 
         public Task DisconnectAsync()
         {
             RawStream = null;
-            return _webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, string.Empty, CancellationToken.None);
+            return _webSocket?.CloseAsync(WebSocketCloseStatus.NormalClosure, string.Empty, CancellationToken.None);
         }
 
         public void Dispose()

Frameworks/MQTTnet.NetStandard/Implementations/WebSocketStream.cs

@@ -9,12 +9,26 @@ namespace MQTTnet.Implementations
     public class WebSocketStream : Stream
     {
         private readonly ClientWebSocket _webSocket;
-
+        
         public WebSocketStream(ClientWebSocket webSocket)
         {
             _webSocket = webSocket;
         }
 
+        public override bool CanRead => true;
+
+        public override bool CanSeek => false;
+
+        public override bool CanWrite => true;
+
+        public override long Length => throw new NotSupportedException();
+
+        public override long Position
+        {
+            get => throw new NotSupportedException();
+            set => throw new NotSupportedException();
+        }
+
         public override void Flush()
         {
         }
@@ -52,21 +66,6 @@ namespace MQTTnet.Implementations
             WriteAsync(buffer, offset, count).GetAwaiter().GetResult();
         }
 
-        public override bool CanRead => true;
-        public override bool CanSeek => false;
-        public override bool CanWrite => true;
-
-        public override long Length
-        {
-            get { throw new NotSupportedException(); }
-        }
-
-        public override long Position
-        {
-            get { throw new NotSupportedException(); }
-            set { throw new NotSupportedException(); }
-        }
-
         public override long Seek(long offset, SeekOrigin origin)
         {
             throw new NotSupportedException();

Frameworks/MQTTnet.UniversalWindows/Implementations/MqttWebSocketChannel.cs

@@ -1,6 +1,5 @@
 using MQTTnet.Core.Channel;
 using MQTTnet.Core.Client;
-using MQTTnet.Core.Exceptions;
 using System;
 using System.IO;
 using System.Net.WebSockets;
@@ -19,19 +18,9 @@ namespace MQTTnet.Implementations
 
         public async Task ConnectAsync(MqttClientOptions options)
         {
-            _webSocket = null;
-
-            try
-            {
-                _webSocket = new ClientWebSocket();
-                await _webSocket.ConnectAsync(new Uri(options.Server), CancellationToken.None);
-
-                RawStream = new WebSocketStream(_webSocket);
-            }
-            catch (WebSocketException exception)
-            {
-                throw new MqttCommunicationException(exception);
-            }
+            _webSocket = new ClientWebSocket();
+            await _webSocket.ConnectAsync(new Uri(options.Server), CancellationToken.None);
+            RawStream = new WebSocketStream(_webSocket);
         }
 
         public Task DisconnectAsync()

MQTTnet.Core/Adapter/MqttChannelCommunicationAdapter.cs

@@ -26,11 +26,19 @@ namespace MQTTnet.Core.Adapter
 
         public IMqttPacketSerializer PacketSerializer { get; }
 
-        public Task ConnectAsync(MqttClientOptions options, TimeSpan timeout)
+        public async Task ConnectAsync(MqttClientOptions options, TimeSpan timeout)
         {
             try
             {
-                return _channel.ConnectAsync(options).TimeoutAfter(timeout);
+                await _channel.ConnectAsync(options).TimeoutAfter(timeout);
+            }
+            catch (MqttCommunicationTimedOutException)
+            {
+                throw;
+            }
+            catch (MqttCommunicationException)
+            {
+                throw;
             }
             catch (Exception exception)
             {
@@ -38,11 +46,19 @@ namespace MQTTnet.Core.Adapter
             }
         }
 
-        public Task DisconnectAsync()
+        public async Task DisconnectAsync()
         {
             try
             {
-                return _channel.DisconnectAsync();
+                await _channel.DisconnectAsync();
+            }
+            catch (MqttCommunicationTimedOutException)
+            {
+                throw;
+            }
+            catch (MqttCommunicationException)
+            {
+                throw;
             }
             catch (Exception exception)
             {
@@ -68,6 +84,14 @@ namespace MQTTnet.Core.Adapter
                 await _sendTask; // configure await false geneates stackoverflow
                 await _channel.SendStream.FlushAsync().TimeoutAfter(timeout).ConfigureAwait(false);
             }
+            catch (MqttCommunicationTimedOutException)
+            {
+                throw;
+            }
+            catch (MqttCommunicationException)
+            {
+                throw;
+            }
             catch (Exception exception)
             {
                 throw new MqttCommunicationException(exception);
@@ -97,13 +121,21 @@ namespace MQTTnet.Core.Adapter
                 MqttTrace.Information(nameof(MqttChannelCommunicationAdapter), "RX <<< {0}", packet);
                 return packet;
             }
+            catch (MqttCommunicationTimedOutException)
+            {
+                throw;
+            }
+            catch (MqttCommunicationException)
+            {
+                throw;
+            }
             catch (Exception exception)
             {
                 throw new MqttCommunicationException(exception);
             }
         }
 
-        private async Task<ReceivedMqttPacket> ReceiveAsync(Stream stream)
+        private static async Task<ReceivedMqttPacket> ReceiveAsync(Stream stream)
         {
             var header = MqttPacketReader.ReadHeaderFromSource(stream);
 

Tests/MQTTnet.TestApp.UniversalWindows/MainPage.xaml.cs

@@ -36,13 +36,14 @@ namespace MQTTnet.TestApp.UniversalWindows
             var options = new MqttClientOptions
             {
                 Server = Server.Text,
+                Port = 8080,
                 UserName = User.Text,
                 Password = Password.Text,
-                ClientId = ClientId.Text
+                ClientId = ClientId.Text,
+                TlsOptions = { UseTls = UseTls.IsChecked == true },
+                ConnectionType = MqttConnectionType.Ws
             };
-
-            options.TlsOptions.UseTls = UseTls.IsChecked == true;
-
+            
             try
             {
                 if (_mqttClient != null)