Fix broken unit tests.

Source/MQTTnet/Implementations/MqttTcpChannel.cs

@@ -1,25 +1,24 @@
 #if !WINDOWS_UWP
+using MQTTnet.Channel;
+using MQTTnet.Client.Options;
 using System;
-using System.Net.Security;
-using System.Net.Sockets;
-using System.Security.Cryptography.X509Certificates;
-using System.Threading.Tasks;
 using System.IO;
 using System.Linq;
+using System.Net.Security;
+using System.Net.Sockets;
 using System.Runtime.ExceptionServices;
+using System.Security.Cryptography.X509Certificates;
 using System.Threading;
-using MQTTnet.Channel;
-using MQTTnet.Client.Options;
-using MQTTnet.Internal;
+using System.Threading.Tasks;
 
 namespace MQTTnet.Implementations
 {
-    public class MqttTcpChannel : Disposable, IMqttChannel
+    public sealed class MqttTcpChannel : IDisposable, IMqttChannel
     {
-        private readonly IMqttClientOptions _clientOptions;
-        private readonly MqttClientTcpOptions _options;
+        readonly IMqttClientOptions _clientOptions;
+        readonly MqttClientTcpOptions _options;
 
-        private Stream _stream;
+        Stream _stream;
 
         public MqttTcpChannel(IMqttClientOptions clientOptions)
         {
@@ -69,7 +68,7 @@ namespace MQTTnet.Implementations
                 // of the actual value.
                 socket.DualMode = _options.DualMode.Value;
             }
-            
+
             // Workaround for: workaround for https://github.com/dotnet/corefx/issues/24430
             using (cancellationToken.Register(() => socket.Dispose()))
             {
@@ -83,7 +82,7 @@ namespace MQTTnet.Implementations
                 var sslStream = new SslStream(networkStream, false, InternalUserCertificateValidationCallback);
                 _stream = sslStream;
 
-                await sslStream.AuthenticateAsClientAsync(_options.Server, LoadCertificates(), _options.TlsOptions.SslProtocol, !_options.TlsOptions.IgnoreCertificateRevocationErrors).ConfigureAwait(false);                
+                await sslStream.AuthenticateAsClientAsync(_options.Server, LoadCertificates(), _options.TlsOptions.SslProtocol, !_options.TlsOptions.IgnoreCertificateRevocationErrors).ConfigureAwait(false);
             }
             else
             {
@@ -95,12 +94,14 @@ namespace MQTTnet.Implementations
 
         public Task DisconnectAsync(CancellationToken cancellationToken)
         {
-            Cleanup();
+            Dispose();
             return Task.FromResult(0);
         }
 
         public async Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
         {
+            if (buffer is null) throw new ArgumentNullException(nameof(buffer));
+
             try
             {
                 // Workaround for: https://github.com/dotnet/corefx/issues/24430
@@ -131,6 +132,8 @@ namespace MQTTnet.Implementations
 
         public async Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
         {
+            if (buffer is null) throw new ArgumentNullException(nameof(buffer));
+
             try
             {
                 // Workaround for: https://github.com/dotnet/corefx/issues/24430
@@ -159,7 +162,7 @@ namespace MQTTnet.Implementations
             }
         }
 
-        private void Cleanup()
+        public void Dispose()
         {
             // When the stream is disposed it will also close the socket and this will also dispose it.
             // So there is no need to dispose the socket again.
@@ -178,16 +181,7 @@ namespace MQTTnet.Implementations
             _stream = null;
         }
 
-        protected override void Dispose(bool disposing)
-        {
-            if (disposing)
-            {
-                Cleanup();
-            }
-            base.Dispose(disposing);
-        }
-
-        private bool InternalUserCertificateValidationCallback(object sender, X509Certificate x509Certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
+        bool InternalUserCertificateValidationCallback(object sender, X509Certificate x509Certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
         {
             if (_options.TlsOptions.CertificateValidationCallback != null)
             {
@@ -218,7 +212,7 @@ namespace MQTTnet.Implementations
             return _options.TlsOptions.AllowUntrustedCertificates;
         }
 
-        private X509CertificateCollection LoadCertificates()
+        X509CertificateCollection LoadCertificates()
         {
             var certificates = new X509CertificateCollection();
             if (_options.TlsOptions.Certificates == null)

Source/MQTTnet/Implementations/PlatformAbstractionLayer.cs

@@ -7,6 +7,7 @@ namespace MQTTnet.Implementations
 {
     public static class PlatformAbstractionLayer
     {
+        // TODO: Consider creating primitives like "MqttNetSocket" which will wrap all required methods and do the platform stuff.
         public static async Task<Socket> AcceptAsync(Socket socket)
         {
 #if NET452 || NET461
@@ -90,7 +91,7 @@ namespace MQTTnet.Implementations
 
         public static Task CompletedTask
         {
-            get 
+            get
             {
 #if NET452 
                 return Task.FromResult(0);

Source/MQTTnet/Internal/Disposable.cs

@@ -2,32 +2,20 @@
 
 namespace MQTTnet.Internal
 {
-    public class Disposable : IDisposable
+    public abstract class Disposable : IDisposable
     {
-        protected bool IsDisposed => _isDisposed;
+        protected bool IsDisposed { get; private set; } = false;
 
         protected void ThrowIfDisposed()
         {
-            if (_isDisposed)
+            if (IsDisposed)
             {
                 throw new ObjectDisposedException(GetType().Name);
             }
         }
 
-
-        #region IDisposable Support
-       
-        private bool _isDisposed = false; // To detect redundant calls
-
         protected virtual void Dispose(bool disposing)
         {
-            if (disposing)
-            {
-                // TODO: dispose managed state (managed objects).
-            }
-
-            // TODO: free unmanaged resources (unmanaged objects) and override a finalizer below.
-            // TODO: set large fields to null.
         }
 
         // TODO: override a finalizer only if Dispose(bool disposing) above has code to free unmanaged resources.
@@ -40,18 +28,17 @@ namespace MQTTnet.Internal
         // This code added to correctly implement the disposable pattern.
         public void Dispose()
         {
-            if (_isDisposed)
+            // Do not change this code. Put cleanup code in Dispose(bool disposing) above.
+
+            if (IsDisposed)
             {
                 return;
             }
 
-            _isDisposed = true;
+            IsDisposed = true;
 
-            // Do not change this code. Put cleanup code in Dispose(bool disposing) above.
             Dispose(true);
-            // TODO: uncomment the following line if the finalizer is overridden above.
-            // GC.SuppressFinalize(this);
+            GC.SuppressFinalize(this);
         }
-        #endregion
     }
 }

Source/MQTTnet/Server/MqttClientSessionsManager.cs

@@ -1,15 +1,16 @@
-using System;
-using System.Collections.Concurrent;
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
-using MQTTnet.Adapter;
+using MQTTnet.Adapter;
 using MQTTnet.Diagnostics;
+using MQTTnet.Exceptions;
 using MQTTnet.Formatter;
 using MQTTnet.Internal;
 using MQTTnet.Packets;
 using MQTTnet.Protocol;
 using MQTTnet.Server.Status;
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace MQTTnet.Server
 {
@@ -236,12 +237,23 @@ namespace MQTTnet.Server
             string clientId = null;
             var clientWasConnected = true;
 
+            MqttConnectPacket connectPacket = null;
+
             try
             {
-                var firstPacket = await channelAdapter.ReceivePacketAsync(_options.DefaultCommunicationTimeout, cancellationToken).ConfigureAwait(false);
-                if (!(firstPacket is MqttConnectPacket connectPacket))
+                try
+                {
+                    var firstPacket = await channelAdapter.ReceivePacketAsync(_options.DefaultCommunicationTimeout, cancellationToken).ConfigureAwait(false);
+                    connectPacket = firstPacket as MqttConnectPacket;
+                    if (connectPacket == null)
+                    {
+                        _logger.Warning(null, "The first packet from client '{0}' was no 'CONNECT' packet [MQTT-3.1.0-1].", channelAdapter.Endpoint);
+                        return;
+                    }
+                }
+                catch (MqttCommunicationTimedOutException)
                 {
-                    _logger.Warning(null, "The first packet from client '{0}' was no 'CONNECT' packet [MQTT-3.1.0-1].", channelAdapter.Endpoint);
+                    _logger.Warning(null, "Client '{0}' connected but did not sent a CONNECT packet.", channelAdapter.Endpoint);
                     return;
                 }
 

Tests/MQTTnet.Core.Tests/Server_Tests.cs

@@ -1,11 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Net.Sockets;
-using System.Text;
-using System.Threading;
-using System.Threading.Tasks;
-using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
 using MQTTnet.Adapter;
 using MQTTnet.Client;
 using MQTTnet.Client.Connecting;
@@ -17,6 +10,13 @@ using MQTTnet.Implementations;
 using MQTTnet.Protocol;
 using MQTTnet.Server;
 using MQTTnet.Tests.Mockups;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net.Sockets;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace MQTTnet.Tests
 {
@@ -54,7 +54,7 @@ namespace MQTTnet.Tests
                 MqttQualityOfServiceLevel.AtMostOnce,
                 "A/B/C",
                 MqttQualityOfServiceLevel.AtMostOnce,
-                1, 
+                1,
                 TestContext);
         }
 
@@ -1050,6 +1050,7 @@ namespace MQTTnet.Tests
                 Assert.AreEqual("c", flow);
 
                 // dc
+                // Connect client with same client ID. Should disconnect existing client.
                 var c2 = await testEnvironment.ConnectClientAsync(clientOptions);
 
                 c2.UseApplicationMessageReceivedHandler(_ =>
@@ -1058,8 +1059,8 @@ namespace MQTTnet.Tests
                     {
                         events.Add("r");
                     }
-
                 });
+
                 c2.SubscribeAsync("topic").Wait();
 
                 await Task.Delay(500);
@@ -1075,12 +1076,11 @@ namespace MQTTnet.Tests
                 flow = string.Join(string.Empty, events);
                 Assert.AreEqual("cdcr", flow);
 
-
                 // nothing
 
                 Assert.AreEqual(false, c1.IsConnected);
                 await c1.DisconnectAsync();
-                Assert.AreEqual (false, c1.IsConnected);
+                Assert.AreEqual(false, c1.IsConnected);
 
                 await Task.Delay(500);
 
@@ -1141,7 +1141,7 @@ namespace MQTTnet.Tests
                 await testEnvironment.ConnectClientAsync();
             }
         }
-        
+
         [TestMethod]
         public async Task Close_Idle_Connection()
         {
@@ -1182,7 +1182,7 @@ namespace MQTTnet.Tests
                 // forever. This is security related.
                 var client = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                 await PlatformAbstractionLayer.ConnectAsync(client, "localhost", testEnvironment.ServerPort);
-                                
+
                 var buffer = Encoding.UTF8.GetBytes("Garbage");
                 client.Send(buffer, buffer.Length, SocketFlags.None);