Expose custom session items in session status.

Build/MQTTnet.nuspec

@@ -25,6 +25,7 @@
 * [Server] Added support for assigned client IDs (MQTTv5 only) (thanks to @bcrosnier).
 * [Server] Added interceptor for unsubscriptions.
 * [Server] Removed exceptions when user properties are set with MQTT protocol version 3.1
+* [Server] Added custom session items to the client status.
 * [MQTTnet.AspNetCore] improved compatibility with AspNetCore 3.1
 * [MQTTnet.Server] Added interceptor for unsubscriptions.
     </releaseNotes>

Source/MQTTnet/Server/MqttClientSession.cs

@@ -8,9 +8,9 @@ namespace MQTTnet.Server
 {
     public class MqttClientSession
     {
-        private readonly IMqttNetLogger _logger;
+        readonly IMqttNetLogger _logger;
 
-        private readonly DateTime _createdTimestamp = DateTime.UtcNow;
+        readonly DateTime _createdTimestamp = DateTime.UtcNow;
 
         public MqttClientSession(string clientId, IDictionary<object, object> items, MqttServerEventDispatcher eventDispatcher, IMqttServerOptions serverOptions, IMqttNetLogger logger)
         {
@@ -73,6 +73,7 @@ namespace MQTTnet.Server
             status.ClientId = ClientId;
             status.CreatedTimestamp = _createdTimestamp;
             status.PendingApplicationMessagesCount = ApplicationMessagesQueue.Count;
+            status.Items = Items;
         }
     }
 }

Source/MQTTnet/Server/Status/IMqttClientStatus.cs

@@ -1,6 +1,6 @@
-using System;
+using MQTTnet.Formatter;
+using System;
 using System.Threading.Tasks;
-using MQTTnet.Formatter;
 
 namespace MQTTnet.Server.Status
 {

Source/MQTTnet/Server/Status/IMqttSessionStatus.cs

@@ -1,12 +1,15 @@
-using System.Threading.Tasks;
+using System.Collections.Generic;
+using System.Threading.Tasks;
 
 namespace MQTTnet.Server.Status
 {
     public interface IMqttSessionStatus
     {
-        string ClientId { get; set; }
+        string ClientId { get; }
 
-        long PendingApplicationMessagesCount { get; set; }
+        long PendingApplicationMessagesCount { get; }
+
+        IDictionary<object, object> Items { get; }
 
         Task ClearPendingApplicationMessagesAsync();
 

Source/MQTTnet/Server/Status/MqttClientStatus.cs

@@ -1,16 +1,16 @@
-using System;
+using MQTTnet.Formatter;
+using System;
 using System.Threading.Tasks;
-using MQTTnet.Formatter;
 
 namespace MQTTnet.Server.Status
 {
     public class MqttClientStatus : IMqttClientStatus
     {
-        private readonly MqttClientConnection _connection;
+        readonly MqttClientConnection _connection;
 
         public MqttClientStatus(MqttClientConnection connection)
         {
-            _connection = connection;
+            _connection = connection ?? throw new ArgumentNullException(nameof(connection));
         }
 
         public string ClientId { get; set; }

Source/MQTTnet/Server/Status/MqttSessionStatus.cs

@@ -1,12 +1,13 @@
 using System;
+using System.Collections.Generic;
 using System.Threading.Tasks;
 
 namespace MQTTnet.Server.Status
 {
     public class MqttSessionStatus : IMqttSessionStatus
     {
-        private readonly MqttClientSession _session;
+        readonly MqttClientSession _session;
-        private readonly MqttClientSessionsManager _sessionsManager;
+        readonly MqttClientSessionsManager _sessionsManager;
 
         public MqttSessionStatus(MqttClientSession session, MqttClientSessionsManager sessionsManager)
         {
@@ -20,6 +21,8 @@ namespace MQTTnet.Server.Status
 
         public DateTime CreatedTimestamp { get; set; }
 
+        public IDictionary<object, object> Items { get; set; }
+
         public Task DeleteAsync()
         {
             return _sessionsManager.DeleteSessionAsync(ClientId);

Tests/MQTTnet.Core.Tests/Session_Tests.cs

@@ -1,10 +1,11 @@
-using System.Text;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
-using System.Threading.Tasks;
-using Microsoft.VisualStudio.TestTools.UnitTesting;
 using MQTTnet.Client;
 using MQTTnet.Client.Subscribing;
 using MQTTnet.Server;
 using MQTTnet.Tests.Mockups;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
 
 namespace MQTTnet.Tests
 {
@@ -42,7 +43,7 @@ namespace MQTTnet.Tests
                 string receivedPayload = null;
 
                 var client = await testEnvironment.ConnectClientAsync();
-                client.UseApplicationMessageReceivedHandler(delegate(MqttApplicationMessageReceivedEventArgs args)
+                client.UseApplicationMessageReceivedHandler(delegate (MqttApplicationMessageReceivedEventArgs args)
                 {
                     receivedPayload = args.ApplicationMessage.ConvertPayloadToString();
                 });
@@ -59,5 +60,29 @@ namespace MQTTnet.Tests
                 Assert.AreEqual("Hello World", receivedPayload);
             }
         }
+
+        [TestMethod]
+        public async Task Get_Session_Items_In_Status()
+        {
+            using (var testEnvironment = new TestEnvironment(TestContext))
+            {
+                var serverOptions = new MqttServerOptionsBuilder()
+                    .WithConnectionValidator(delegate (MqttConnectionValidatorContext context)
+                    {
+                        // Don't validate anything. Just set some session items.
+                        context.SessionItems["can_subscribe_x"] = true;
+                        context.SessionItems["default_payload"] = "Hello World";
+                    });
+
+                await testEnvironment.StartServerAsync(serverOptions);
+
+                var client = await testEnvironment.ConnectClientAsync();
+
+                var sessionStatus = await testEnvironment.Server.GetSessionStatusAsync();
+                var session = sessionStatus.First();
+
+                Assert.AreEqual(true, session.Items["can_subscribe_x"]);
+            }
+        }
     }
 }