Server refactoring

Frameworks/MQTTnet.NetStandard/MqttFactory.cs

@@ -4,6 +4,7 @@ using MQTTnet.Core.Client;
 using MQTTnet.Core.Serializer;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Options;
 using MQTTnet.Implementations;
 using MQTTnet.Core.ManagedClient;
 using MQTTnet.Core.Server;
@@ -90,9 +91,15 @@ namespace MQTTnet
             };
         }
 
-        public MqttClientSession CreateClientSession(string sessionId, MqttClientSessionsManager mqttClientSessionsManager)
+        public MqttClientSession CreateClientSession(string clientId, MqttClientSessionsManager clientSessionsManager)
         {
-            return new MqttClientSession(sessionId, mqttClientSessionsManager, _serviceProvider.GetRequiredService<ILogger<MqttClientSession>>(), _serviceProvider.GetRequiredService<ILogger<MqttClientPendingMessagesQueue>>());
+            return new MqttClientSession(
+                clientId,
+                _serviceProvider.GetRequiredService<IOptions<MqttServerOptions>>(),
+                clientSessionsManager,
+                _serviceProvider.GetRequiredService<MqttClientSubscriptionsManager>(),
+                _serviceProvider.GetRequiredService<ILogger<MqttClientSession>>(), 
+                _serviceProvider.GetRequiredService<ILogger<MqttClientPendingMessagesQueue>>());
         }
 
         public IMqttClient CreateMqttClient()

Frameworks/MQTTnet.NetStandard/ServiceCollectionExtensions.cs

@@ -34,6 +34,7 @@ namespace MQTTnet
             services.AddTransient<IMqttPacketSerializer, MqttPacketSerializer>();
 
             services.AddTransient<MqttClientSessionsManager>();
+            services.AddTransient<MqttClientSubscriptionsManager>();
             services.AddTransient<MqttClientRetainedMessagesManager>();
             return services;
         }

Frameworks/MQTTnet.UniversalWindows/MqttFactory.cs

@@ -1,6 +1,7 @@
 using System;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
 using MQTTnet.Core.Adapter;
 using MQTTnet.Core.Channel;
 using MQTTnet.Core.Client;
@@ -85,9 +86,15 @@ namespace MQTTnet
             };
         }
 
-        public MqttClientSession CreateClientSession(string sessionId, MqttClientSessionsManager mqttClientSessionsManager)
+        public MqttClientSession CreateClientSession(string clientId, MqttClientSessionsManager clientSessionsManager)
         {
-            return new MqttClientSession(sessionId, mqttClientSessionsManager, _serviceProvider.GetRequiredService<ILogger<MqttClientSession>>(), _serviceProvider.GetRequiredService<ILogger<MqttClientPendingMessagesQueue>>());
+            return new MqttClientSession(
+                clientId,
+                _serviceProvider.GetRequiredService<IOptions<MqttServerOptions>>(),
+                clientSessionsManager,
+                _serviceProvider.GetRequiredService<MqttClientSubscriptionsManager>(),
+                _serviceProvider.GetRequiredService<ILogger<MqttClientSession>>(),
+                _serviceProvider.GetRequiredService<ILogger<MqttClientPendingMessagesQueue>>());
         }
 
         public IMqttClient CreateMqttClient()

MQTTnet.Core/ApplicationMessagePublisherExtensions.cs

@@ -0,0 +1,16 @@
+using System;
+using System.Threading.Tasks;
+
+namespace MQTTnet.Core
+{
+    public static class ApplicationMessagePublisherExtensions
+    {
+        public static Task PublishAsync(this IApplicationMessagePublisher client, params MqttApplicationMessage[] applicationMessages)
+        {
+            if (client == null) throw new ArgumentNullException(nameof(client));
+            if (applicationMessages == null) throw new ArgumentNullException(nameof(applicationMessages));
+
+            return client.PublishAsync(applicationMessages);
+        }
+    }
+}

MQTTnet.Core/Client/MqttClientExtensions.cs

@@ -7,14 +7,6 @@ namespace MQTTnet.Core.Client
 {
     public static class MqttClientExtensions
     {
-        public static Task PublishAsync(this IApplicationMessagePublisher client, params MqttApplicationMessage[] applicationMessages)
-        {
-            if (client == null) throw new ArgumentNullException(nameof(client));
-            if (applicationMessages == null) throw new ArgumentNullException(nameof(applicationMessages));
-
-            return client.PublishAsync(applicationMessages);
-        }
-
         public static Task<IList<MqttSubscribeResult>> SubscribeAsync(this IMqttClient client, params TopicFilter[] topicFilters)
         {
             if (client == null) throw new ArgumentNullException(nameof(client));

MQTTnet.Core/IApplicationMessagePublisher.cs

@@ -1,7 +1,7 @@
 using System.Collections.Generic;
 using System.Threading.Tasks;
 
-namespace MQTTnet.Core.Client
+namespace MQTTnet.Core
 {
     public interface IApplicationMessagePublisher
     {

MQTTnet.Core/IApplicationMessageReceiver.cs

@@ -1,6 +1,7 @@
 using System;
+using MQTTnet.Core.Client;
 
-namespace MQTTnet.Core.Client
+namespace MQTTnet.Core
 {
     public interface IApplicationMessageReceiver
     {

MQTTnet.Core/ManagedClient/ManagedMqttClient.cs

@@ -91,16 +91,15 @@ namespace MQTTnet.Core.ManagedClient
             return Task.FromResult(0);
         }
 
-        public Task PublishAsync(IEnumerable<MqttApplicationMessage> applicationMessages)
+        public async Task PublishAsync(IEnumerable<MqttApplicationMessage> applicationMessages)
         {
             if (applicationMessages == null) throw new ArgumentNullException(nameof(applicationMessages));
 
             foreach (var applicationMessage in applicationMessages)
             {
+                await _storageManager.AddAsync(applicationMessage).ConfigureAwait(false);
                 _messageQueue.Add(applicationMessage);
             }
-
-            return Task.FromResult(0);
         }
 
         public Task SubscribeAsync(IEnumerable<TopicFilter> topicFilters)
@@ -208,6 +207,7 @@ namespace MQTTnet.Core.ManagedClient
                     }
 
                     await TryPublishQueuedMessageAsync(message).ConfigureAwait(false);
+                    await _storageManager.RemoveAsync(message).ConfigureAwait(false);
                 }
             }
             catch (OperationCanceledException)

MQTTnet.Core/ManagedClient/ManagedMqttClientExtensions.cs

@@ -1,26 +1,18 @@
 using System;
 using System.Threading.Tasks;
-using MQTTnet.Core.Packets;
 
 namespace MQTTnet.Core.ManagedClient
 {
     public static class ManagedMqttClientExtensions
     {
-        public static Task EnqueueAsync(this ManagedMqttClient managedClient, params MqttApplicationMessage[] applicationMessages)
-        {
-            if (managedClient == null) throw new ArgumentNullException(nameof(managedClient));
-
-            return managedClient.EnqueueAsync(applicationMessages);
-        }
-
-        public static Task SubscribeAsync(this ManagedMqttClient managedClient, params TopicFilter[] topicFilters)
+        public static Task SubscribeAsync(this IManagedMqttClient managedClient, params TopicFilter[] topicFilters)
         {
             if (managedClient == null) throw new ArgumentNullException(nameof(managedClient));
 
             return managedClient.SubscribeAsync(topicFilters);
         }
 
-        public static Task UnsubscribeAsync(this ManagedMqttClient managedClient, params TopicFilter[] topicFilters)
+        public static Task UnsubscribeAsync(this IManagedMqttClient managedClient, params TopicFilter[] topicFilters)
         {
             if (managedClient == null) throw new ArgumentNullException(nameof(managedClient));
 

MQTTnet.Core/MqttApplicationMessageReceivedEventArgs.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace MQTTnet.Core.Client
+namespace MQTTnet.Core
 {
     public sealed class MqttApplicationMessageReceivedEventArgs : EventArgs
     {

MQTTnet.Core/Server/IMqttServer.cs

@@ -11,6 +11,7 @@ namespace MQTTnet.Core.Server
         event EventHandler<MqttClientDisconnectedEventArgs> ClientDisconnected;
 
         IList<ConnectedMqttClient> GetConnectedClients();
+        void Publish(IEnumerable<MqttApplicationMessage> applicationMessages);
 
         Task StartAsync();
         Task StopAsync();

MQTTnet.Core/Server/MqttClientSession.cs

@@ -9,6 +9,7 @@ using MQTTnet.Core.Packets;
 using MQTTnet.Core.Protocol;
 using MQTTnet.Core.Serializer;
 using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
 
 namespace MQTTnet.Core.Server
 {
@@ -16,8 +17,8 @@ namespace MQTTnet.Core.Server
     {
         private readonly HashSet<ushort> _unacknowledgedPublishPackets = new HashSet<ushort>();
 
-        private readonly MqttClientSubscriptionsManager _subscriptionsManager = new MqttClientSubscriptionsManager();
-        private readonly MqttClientSessionsManager _mqttClientSessionsManager;
+        private readonly MqttClientSubscriptionsManager _subscriptionsManager;
+        private readonly MqttClientSessionsManager _sessionsManager;
         private readonly MqttClientPendingMessagesQueue _pendingMessagesQueue;
         private readonly MqttServerOptions _options;
         private readonly ILogger<MqttClientSession> _logger;
@@ -26,14 +27,22 @@ namespace MQTTnet.Core.Server
         private CancellationTokenSource _cancellationTokenSource;
         private MqttApplicationMessage _willMessage;
 
-        public MqttClientSession(string clientId, MqttClientSessionsManager mqttClientSessionsManager, ILogger<MqttClientSession> logger, ILogger<MqttClientPendingMessagesQueue> msgQueueLogger)
+        public MqttClientSession(
+            string clientId, 
+            IOptions<MqttServerOptions> options,
+            MqttClientSessionsManager sessionsManager,
+            MqttClientSubscriptionsManager subscriptionsManager,
+            ILogger<MqttClientSession> logger, 
+            ILogger<MqttClientPendingMessagesQueue> messageQueueLogger)
         {
-            _mqttClientSessionsManager = mqttClientSessionsManager ?? throw new ArgumentNullException(nameof(mqttClientSessionsManager));
+            _sessionsManager = sessionsManager ?? throw new ArgumentNullException(nameof(sessionsManager));
+            _subscriptionsManager = subscriptionsManager ?? throw new ArgumentNullException(nameof(sessionsManager));
             _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+
             ClientId = clientId;
 
-            _options = mqttClientSessionsManager.Options;
-            _pendingMessagesQueue = new MqttClientPendingMessagesQueue(mqttClientSessionsManager.Options, this, msgQueueLogger);
+            _options = options.Value;
+            _pendingMessagesQueue = new MqttClientPendingMessagesQueue(_options, this, messageQueueLogger);
         }
 
         public string ClientId { get; }
@@ -84,7 +93,7 @@ namespace MQTTnet.Core.Server
             {
                 if (_willMessage != null)
                 {
-                    _mqttClientSessionsManager.DispatchApplicationMessage(this, _willMessage);
+                    _sessionsManager.DispatchApplicationMessage(this, _willMessage);
                 }
             }
         }
@@ -177,7 +186,7 @@ namespace MQTTnet.Core.Server
 
         private void EnqueueRetainedMessages(MqttSubscribePacket subscribePacket)
         {
-            var retainedMessages = _mqttClientSessionsManager.RetainedMessagesManager.GetMessages(subscribePacket);
+            var retainedMessages = _sessionsManager.RetainedMessagesManager.GetMessages(subscribePacket);
             foreach (var publishPacket in retainedMessages)
             {
                 EnqueuePublishPacket(publishPacket.ToPublishPacket());
@@ -191,19 +200,19 @@ namespace MQTTnet.Core.Server
 
             if (applicationMessage.Retain)
             {
-                await _mqttClientSessionsManager.RetainedMessagesManager.HandleMessageAsync(ClientId, applicationMessage);
+                await _sessionsManager.RetainedMessagesManager.HandleMessageAsync(ClientId, applicationMessage);
             }
 
             switch (applicationMessage.QualityOfServiceLevel)
             {
                 case MqttQualityOfServiceLevel.AtMostOnce:
                     {
-                        _mqttClientSessionsManager.DispatchApplicationMessage(this, applicationMessage);
+                        _sessionsManager.DispatchApplicationMessage(this, applicationMessage);
                         return;
                     }
                 case MqttQualityOfServiceLevel.AtLeastOnce:
                     {
-                        _mqttClientSessionsManager.DispatchApplicationMessage(this, applicationMessage);
+                        _sessionsManager.DispatchApplicationMessage(this, applicationMessage);
 
                         await adapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, _cancellationTokenSource.Token,
                             new MqttPubAckPacket { PacketIdentifier = publishPacket.PacketIdentifier });
@@ -218,7 +227,7 @@ namespace MQTTnet.Core.Server
                             _unacknowledgedPublishPackets.Add(publishPacket.PacketIdentifier);
                         }
 
-                        _mqttClientSessionsManager.DispatchApplicationMessage(this, applicationMessage);
+                        _sessionsManager.DispatchApplicationMessage(this, applicationMessage);
 
                         await adapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, _cancellationTokenSource.Token,
                             new MqttPubRecPacket { PacketIdentifier = publishPacket.PacketIdentifier });

MQTTnet.Core/Server/MqttClientSessionsManager.cs

@@ -11,7 +11,6 @@ using MQTTnet.Core.Protocol;
 using MQTTnet.Core.Serializer;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
-using MQTTnet.Core.Client;
 
 namespace MQTTnet.Core.Server
 {
@@ -19,14 +18,19 @@ namespace MQTTnet.Core.Server
     {
         private readonly Dictionary<string, MqttClientSession> _clientSessions = new Dictionary<string, MqttClientSession>();
         private readonly ILogger<MqttClientSessionsManager> _logger;
-        private readonly IMqttClientSesssionFactory _mqttClientSesssionFactory;
+        private readonly IMqttClientSesssionFactory _clientSesssionFactory;
+        private readonly MqttServerOptions _options;
 
-        public MqttClientSessionsManager(IOptions<MqttServerOptions> options, ILogger<MqttClientSessionsManager> logger, MqttClientRetainedMessagesManager retainedMessagesManager, IMqttClientSesssionFactory mqttClientSesssionFactory)
+        public MqttClientSessionsManager(
+            IOptions<MqttServerOptions> options, 
+            ILogger<MqttClientSessionsManager> logger,
+            MqttClientRetainedMessagesManager retainedMessagesManager, 
+            IMqttClientSesssionFactory clientSesssionFactory)
         {
             _logger = logger ?? throw new ArgumentNullException(nameof(logger));
-            Options = options.Value ?? throw new ArgumentNullException(nameof(options));
+            _options = options.Value ?? throw new ArgumentNullException(nameof(options));
             RetainedMessagesManager = retainedMessagesManager ?? throw new ArgumentNullException(nameof(options));
-            _mqttClientSesssionFactory = mqttClientSesssionFactory ?? throw new ArgumentNullException(nameof(mqttClientSesssionFactory));
+            _clientSesssionFactory = clientSesssionFactory ?? throw new ArgumentNullException(nameof(clientSesssionFactory));
         }
 
         public event EventHandler<MqttClientConnectedEventArgs> ClientConnected;
@@ -34,14 +38,13 @@ namespace MQTTnet.Core.Server
         public event EventHandler<MqttApplicationMessageReceivedEventArgs> ApplicationMessageReceived;
 
         public MqttClientRetainedMessagesManager RetainedMessagesManager { get; }
-        public MqttServerOptions Options { get; }
 
         public async Task RunClientSessionAsync(IMqttCommunicationAdapter clientAdapter)
         {
             var clientId = string.Empty;
             try
             {
-                if (!(await clientAdapter.ReceivePacketAsync(Options.DefaultCommunicationTimeout, CancellationToken.None).ConfigureAwait(false) is MqttConnectPacket connectPacket))
+                if (!(await clientAdapter.ReceivePacketAsync(_options.DefaultCommunicationTimeout, CancellationToken.None).ConfigureAwait(false) is MqttConnectPacket connectPacket))
                 {
                     throw new MqttProtocolViolationException("The first packet from a client must be a 'CONNECT' packet [MQTT-3.1.0-1].");
                 }
@@ -50,11 +53,11 @@ namespace MQTTnet.Core.Server
 
                 // Switch to the required protocol version before sending any response.
                 clientAdapter.PacketSerializer.ProtocolVersion = connectPacket.ProtocolVersion;
-                
+
                 var connectReturnCode = ValidateConnection(connectPacket);
                 if (connectReturnCode != MqttConnectReturnCode.ConnectionAccepted)
                 {
-                    await clientAdapter.SendPacketsAsync(Options.DefaultCommunicationTimeout, CancellationToken.None, new MqttConnAckPacket
+                    await clientAdapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, CancellationToken.None, new MqttConnAckPacket
                     {
                         ConnectReturnCode = connectReturnCode
                     }).ConfigureAwait(false);
@@ -64,7 +67,7 @@ namespace MQTTnet.Core.Server
 
                 var clientSession = GetOrCreateClientSession(connectPacket);
 
-                await clientAdapter.SendPacketsAsync(Options.DefaultCommunicationTimeout, CancellationToken.None, new MqttConnAckPacket
+                await clientAdapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, CancellationToken.None, new MqttConnAckPacket
                 {
                     ConnectReturnCode = connectReturnCode,
                     IsSessionPresent = clientSession.IsExistingSession
@@ -89,7 +92,7 @@ namespace MQTTnet.Core.Server
             {
                 try
                 {
-                    await clientAdapter.DisconnectAsync(Options.DefaultCommunicationTimeout).ConfigureAwait(false);
+                    await clientAdapter.DisconnectAsync(_options.DefaultCommunicationTimeout).ConfigureAwait(false);
                 }
                 catch (Exception)
                 {
@@ -147,9 +150,9 @@ namespace MQTTnet.Core.Server
 
         private MqttConnectReturnCode ValidateConnection(MqttConnectPacket connectPacket)
         {
-            if (Options.ConnectionValidator != null)
+            if (_options.ConnectionValidator != null)
             {
-                return Options.ConnectionValidator(connectPacket);
+                return _options.ConnectionValidator(connectPacket);
             }
 
             return MqttConnectReturnCode.ConnectionAccepted;
@@ -181,7 +184,7 @@ namespace MQTTnet.Core.Server
                 {
                     isExistingSession = false;
 
-                    clientSession = _mqttClientSesssionFactory.CreateClientSession(connectPacket.ClientId, this);
+                    clientSession = _clientSesssionFactory.CreateClientSession(connectPacket.ClientId, this);
                     _clientSessions[connectPacket.ClientId] = clientSession;
 
                     _logger.LogTrace("Created a new session for client '{0}'.", connectPacket.ClientId);

MQTTnet.Core/Server/MqttClientSubscriptionsManager.cs

@@ -9,6 +9,11 @@ namespace MQTTnet.Core.Server
     {
         private readonly Dictionary<string, MqttQualityOfServiceLevel> _subscribedTopics = new Dictionary<string, MqttQualityOfServiceLevel>();
 
+        public MqttClientSubscriptionsManager()
+        {
+            
+        }
+
         public MqttSubAckPacket Subscribe(MqttSubscribePacket subscribePacket)
         {
             if (subscribePacket == null) throw new ArgumentNullException(nameof(subscribePacket));
@@ -19,6 +24,8 @@ namespace MQTTnet.Core.Server
             {
                 foreach (var topicFilter in subscribePacket.TopicFilters)
                 {
+
+
                     _subscribedTopics[topicFilter.Topic] = topicFilter.QualityOfServiceLevel;
                     responsePacket.SubscribeReturnCodes.Add(MqttSubscribeReturnCode.SuccessMaximumQoS1); // TODO: Add support for QoS 2.
                 }

MQTTnet.Core/Server/MqttServer.cs

@@ -6,7 +6,6 @@ using MQTTnet.Core.Adapter;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using System.Linq;
-using MQTTnet.Core.Client;
 
 namespace MQTTnet.Core.Server
 {
@@ -46,7 +45,7 @@ namespace MQTTnet.Core.Server
         public event EventHandler<MqttClientDisconnectedEventArgs> ClientDisconnected;
         public event EventHandler<MqttApplicationMessageReceivedEventArgs> ApplicationMessageReceived;
 
-        public Task PublishAsync(IEnumerable<MqttApplicationMessage> applicationMessages)
+        public void Publish(IEnumerable<MqttApplicationMessage> applicationMessages)
         {
             if (applicationMessages == null) throw new ArgumentNullException(nameof(applicationMessages));
 
@@ -60,7 +59,11 @@ namespace MQTTnet.Core.Server
                 _options.ApplicationMessageInterceptor?.Invoke(applicationMessage);
                 _clientSessionsManager.DispatchApplicationMessage(null, applicationMessage);
             }
-            
+        }
+
+        public Task PublishAsync(IEnumerable<MqttApplicationMessage> applicationMessages)
+        {
+            Publish(applicationMessages);
             return Task.FromResult(0);
         }
 

MQTTnet.Core/Server/MqttSubscribeResult.cs

@@ -0,0 +1,11 @@
+using MQTTnet.Core.Packets;
+
+namespace MQTTnet.Core.Server
+{
+    public class MqttSubscribeResult
+    {
+        public MqttSubAckPacket ResponsePacket { get; set; }
+
+        public bool CloseConnection { get; set; }
+    }
+}

Tests/MQTTnet.Core.Tests/TestClientSessionFactory.cs

@@ -1,12 +1,14 @@
-using MQTTnet.Core.Server;
+using System;
+using MQTTnet.Core.Server;
 
 namespace MQTTnet.Core.Tests
 {
     public class TestClientSessionFactory : IMqttClientSesssionFactory
     {
-        public MqttClientSession CreateClientSession(string sessionId, MqttClientSessionsManager mqttClientSessionsManager)
+        public MqttClientSession CreateClientSession(string clientId, MqttClientSessionsManager mqttClientSessionsManager)
         {
-            return new MqttClientSession(sessionId, mqttClientSessionsManager, new TestLogger<MqttClientSession>(), new TestLogger<MqttClientPendingMessagesQueue>());
+            throw new NotImplementedException();
+            //return new MqttClientSession(clientId, mqttClientSessionsManager, new TestLogger<MqttClientSession>(), new TestLogger<MqttClientPendingMessagesQueue>());
         }
     }
 }

Tests/MQTTnet.TestApp.NetCore/ManagedClientTest.cs

@@ -50,14 +50,14 @@ namespace MQTTnet.TestApp.NetCore
                     Console.WriteLine(">> RECEIVED: " + e.ApplicationMessage.Topic);
                 };
 
-                await managedClient.EnqueueAsync(new MqttApplicationMessageBuilder().WithTopic("Step").WithPayload("1").Build());
-                await managedClient.EnqueueAsync(new MqttApplicationMessageBuilder().WithTopic("Step").WithPayload("2").WithAtLeastOnceQoS().Build());
+                await managedClient.PublishAsync(new MqttApplicationMessageBuilder().WithTopic("Step").WithPayload("1").Build());
+                await managedClient.PublishAsync(new MqttApplicationMessageBuilder().WithTopic("Step").WithPayload("2").WithAtLeastOnceQoS().Build());
 
                 await managedClient.StartAsync(options);
 
                 await managedClient.SubscribeAsync(new TopicFilter("xyz", MqttQualityOfServiceLevel.AtMostOnce));
 
-                await managedClient.EnqueueAsync(new MqttApplicationMessageBuilder().WithTopic("Step").WithPayload("3").Build());
+                await managedClient.PublishAsync(new MqttApplicationMessageBuilder().WithTopic("Step").WithPayload("3").Build());
 
                 Console.WriteLine("Managed client started.");
                 Console.ReadLine();

Tests/MQTTnet.TestApp.UniversalWindows/MainPage.xaml

@@ -65,7 +65,6 @@
                     <Button Click="Publish" Width="120">Publish</Button>
                 </StackPanel>
             </PivotItem>
-
             <PivotItem Header="Subscribe">
                 <StackPanel Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
                     <TextBlock>Topic:</TextBlock>
@@ -84,6 +83,12 @@
                     </StackPanel>
                 </StackPanel>
             </PivotItem>
+            <PivotItem Header="Server">
+                <StackPanel Orientation="Horizontal">
+                    <Button Width="120" Margin="0,0,10,0" Click="StartServer">Start</Button>
+                    <Button Width="120" Margin="0,0,10,0" Click="StopServer">Stop</Button>
+                </StackPanel>
+            </PivotItem>
         </Pivot>
 
         <ScrollViewer Margin="12,10,12,0" Grid.Row="1" Background="Black" Foreground="WhiteSmoke" FontFamily="Consolas" HorizontalScrollMode="Enabled" VerticalScrollMode="Enabled" HorizontalScrollBarVisibility="Visible" VerticalScrollBarVisibility="Visible">

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

@@ -9,6 +9,7 @@ using MQTTnet.Core;
 using MQTTnet.Core.Client;
 using MQTTnet.Core.Diagnostics;
 using MQTTnet.Core.Protocol;
+using MQTTnet.Core.Server;
 using MQTTnet.Implementations;
 
 namespace MQTTnet.TestApp.UniversalWindows
@@ -16,6 +17,7 @@ namespace MQTTnet.TestApp.UniversalWindows
     public sealed partial class MainPage
     {
         private IMqttClient _mqttClient;
+        private IMqttServer _mqttServer;
 
         public MainPage()
         {
@@ -319,5 +321,27 @@ namespace MQTTnet.TestApp.UniversalWindows
             };
 
         }
+
+        private async void StartServer(object sender, RoutedEventArgs e)
+        {
+            if (_mqttServer != null)
+            {
+                return;
+            }
+
+            _mqttServer = new MqttFactory().CreateMqttServer();
+            await _mqttServer.StartAsync();
+        }
+
+        private async void StopServer(object sender, RoutedEventArgs e)
+        {
+            if (_mqttServer == null)
+            {
+                return;
+            }
+
+            await _mqttServer.StopAsync();
+            _mqttServer = null;
+        }
     }
 }