Refactor ASP.NET integration.

Frameworks/MQTTnet.AspnetCore/ApplicationBuilderExtensions.cs

@@ -13,32 +13,26 @@ namespace MQTTnet.AspNetCore
             app.UseWebSockets();
             app.Use(async (context, next) =>
             {
-                if (context.Request.Path == path && context.WebSockets.IsWebSocketRequest)
-                {
-                    string subprotocol = null;
-
-                    if (context.Request.Headers.TryGetValue("Sec-WebSocket-Protocol", out var requestedSubProtocolValues))
-                    {
-                        // Order the protocols to also match "mqtt", "mqttv-3.1", "mqttv-3.11" etc.
-                        subprotocol = requestedSubProtocolValues
-                            .OrderByDescending(p => p.Length)
-                            .FirstOrDefault(p => p.ToLower().StartsWith("mqtt"));
-                    }
-
-                    if (subprotocol == null)
-                    {
-                        return;
-                    }
-
-                    var adapter = app.ApplicationServices.GetRequiredService<MqttWebSocketServerAdapter>();
-                    using (var webSocket = await context.WebSockets.AcceptWebSocketAsync(subprotocol))
-                    {
-                        await adapter.AcceptWebSocketAsync(webSocket);
-                    }
-                }
-                else
+                if (!context.WebSockets.IsWebSocketRequest || context.Request.Path != path)
                 {
                     await next();
+                    return;
+                }
+
+                string subProtocol = null;
+
+                if (context.Request.Headers.TryGetValue("Sec-WebSocket-Protocol", out var requestedSubProtocolValues))
+                {
+                    // Order the protocols to also match "mqtt", "mqttv-3.1", "mqttv-3.11" etc.
+                    subProtocol = requestedSubProtocolValues
+                        .OrderByDescending(p => p.Length)
+                        .FirstOrDefault(p => p.ToLower().StartsWith("mqtt"));
+                }
+
+                var adapter = app.ApplicationServices.GetRequiredService<MqttWebSocketServerAdapter>();
+                using (var webSocket = await context.WebSockets.AcceptWebSocketAsync(subProtocol))
+                {
+                    await adapter.AcceptWebSocketAsync(webSocket);
                 }
             });
 

Frameworks/MQTTnet.AspnetCore/MqttWebSocketServerAdapter.cs

@@ -23,7 +23,7 @@ namespace MQTTnet.AspNetCore
             return Task.CompletedTask;
         }
 
-        public Task AcceptWebSocketAsync(WebSocket webSocket)
+        public async Task AcceptWebSocketAsync(WebSocket webSocket)
         {
             if (webSocket == null) throw new ArgumentNullException(nameof(webSocket));
 
@@ -31,7 +31,11 @@ namespace MQTTnet.AspNetCore
 
             var eventArgs = new MqttServerAdapterClientAcceptedEventArgs(clientAdapter);
             ClientAccepted?.Invoke(this, eventArgs);
-            return eventArgs.SessionTask ?? Task.CompletedTask;
+
+            if (eventArgs.SessionTask != null)
+            {
+                await eventArgs.SessionTask.ConfigureAwait(false);
+            }
         }
         
         public void Dispose()

Frameworks/MQTTnet.NetStandard/Server/MqttServer.cs

@@ -81,14 +81,14 @@ namespace MQTTnet.Server
             _cancellationTokenSource = new CancellationTokenSource();
 
             _retainedMessagesManager = new MqttRetainedMessagesManager(Options, _logger);
-            await _retainedMessagesManager.LoadMessagesAsync();
+            await _retainedMessagesManager.LoadMessagesAsync().ConfigureAwait(false);
 
             _clientSessionsManager = new MqttClientSessionsManager(Options, this, _retainedMessagesManager, _logger);
 
             foreach (var adapter in _adapters)
             {
                 adapter.ClientAccepted += OnClientAccepted;
-                await adapter.StartAsync(Options);
+                await adapter.StartAsync(Options).ConfigureAwait(false);
             }
 
             _logger.Info("Started.");
@@ -110,10 +110,10 @@ namespace MQTTnet.Server
                 foreach (var adapter in _adapters)
                 {
                     adapter.ClientAccepted -= OnClientAccepted;
-                    await adapter.StopAsync();
+                    await adapter.StopAsync().ConfigureAwait(false);
                 }
 
-                await _clientSessionsManager.StopAsync();
+                await _clientSessionsManager.StopAsync().ConfigureAwait(false);
 
                 _logger.Info("Stopped.");
             }

Tests/MQTTnet.TestApp.AspNetCore2/wwwroot/app/app.ts

@@ -2,7 +2,7 @@
 
 var client = connect('ws://' + location.host + '/mqtt',
     {
-        clientId: "client1",
+        clientId: "client" + Math.floor(Math.random() * 6) + 1
     });
 
 window.onbeforeunload = () => {
@@ -23,11 +23,12 @@ publishButton.onclick = click => {
 
 client.on('connect', () => {
     client.subscribe('#', { qos: 0 }, (err, granted) => {
-        console.log(err);   
+        console.log(err);
     });
     client.publish('presence', 'Hello mqtt');
 
     stateParagraph.innerText = "connected";
+    showMsg("[connect]");
 });
 
 client.on("error", e => {
@@ -36,6 +37,7 @@ client.on("error", e => {
 
 client.on("reconnect", () => {
     stateParagraph.innerText = "reconnecting";
+    showMsg("[reconnect]");
 });
 
 client.on('message', (topic, message) => {
@@ -50,7 +52,7 @@ function showMsg(msg: string) {
 
     msgsList.appendChild(node);
 
-    if (msgsList.childElementCount > 20) {
+    if (msgsList.childElementCount > 50) {
         msgsList.removeChild(msgsList.childNodes[0]);
     }
 }

Tests/MQTTnet.TestApp.UniversalWindows/MQTTnet.TestApp.UniversalWindows.csproj

@@ -138,7 +138,7 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="Microsoft.NETCore.UniversalWindowsPlatform">
-      <Version>6.0.8</Version>
+      <Version>6.1.4</Version>
     </PackageReference>
     <PackageReference Include="Microsoft.Toolkit.Uwp.UI.Controls">
       <Version>2.2.0</Version>