Use internal class instead of interface

Author: Y-Sindo

src/Microsoft.Azure.SignalR/HubHost/ServiceLifetimeManager.cs

@@ -53,11 +53,11 @@ public ServiceLifetimeManager(
 
         public override Task OnConnectedAsync(HubConnectionContext connection)
         {
-            var userIdFeature = connection.Features.Get<IServiceUserIdFeature>();
+            var userIdFeature = connection.Features.Get<ServiceUserIdFeature>();
             if (userIdFeature != null)
             {
                 connection.UserIdentifier = userIdFeature.UserId;
-                connection.Features.Set<IServiceUserIdFeature>(null);
+                connection.Features.Set<ServiceUserIdFeature>(null);
             }
             return base.OnConnectedAsync(connection);
         }

src/Microsoft.Azure.SignalR/Internals/IServiceUserNameFeature.cs

@@ -1,9 +1,16 @@
 // Copyright (c) Microsoft. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
+using Microsoft.AspNetCore.SignalR;
+
 namespace Microsoft.Azure.SignalR
 {
-    internal class ServiceUserIdFeature : IServiceUserIdFeature
+    /// <summary>
+    /// When clients negotiate with Management SDK and connect to SignalR server, the <see cref="IUserIdProvider"/> might not work as the user Id is set directly in the Management SDK.
+    /// To make <see cref="HubConnectionContext.UserIdentifier"/> have the valid value in this case, we should set it before the server can access it. <see cref="HubLifetimeManager{THub}.OnConnectedAsync(HubConnectionContext)"/> is the only chance we can set the value. However, we cannot access the <see cref="Constants.ClaimType.UserId"/> as ASRS system claims're trimmed there. <see cref="HubConnectionContext.Features"/> is the place where we can store the user Id.
+    /// https://github.com/dotnet/aspnetcore/blob/v6.0.9/src/SignalR/server/Core/src/HubConnectionHandler.cs#L132-L141
+    /// </summary>
+    internal class ServiceUserIdFeature
     {
         public string UserId { get; }
 

src/Microsoft.Azure.SignalR/Internals/ServiceUserIdFeature.cs

@@ -251,7 +251,7 @@ private FeatureCollection BuildFeatures(OpenConnectionMessage serviceMessage)
             var userIdClaim = serviceMessage.Claims.FirstOrDefault(c => c.Type == Constants.ClaimType.UserId);
             if (userIdClaim != default)
             {
-                features.Set<IServiceUserIdFeature>(new ServiceUserIdFeature(userIdClaim.Value));
+                features.Set(new ServiceUserIdFeature(userIdClaim.Value));
             }
             return features;
         }

src/Microsoft.Azure.SignalR/ServerConnections/ClientConnectionContext.cs

@@ -14,7 +14,7 @@ public void SetUserIdFeatureTest()
         {
             var claims = new Claim[] { new(Constants.ClaimType.UserId, "testUser") };
             var connection = new ClientConnectionContext(new("connectionId", claims));
-            var feature = connection.Features.Get<IServiceUserIdFeature>();
+            var feature = connection.Features.Get<ServiceUserIdFeature>();
             Assert.NotNull(feature);
             Assert.Equal("testUser", feature.UserId);
         }
@@ -23,7 +23,7 @@ public void SetUserIdFeatureTest()
         public void DoNotSetUserIdFeatureWithoutUserIdClaimTest()
         {
             var connection = new ClientConnectionContext(new("connectionId", Array.Empty<Claim>()));
-            var feature = connection.Features.Get<IServiceUserIdFeature>();
+            var feature = connection.Features.Get<ServiceUserIdFeature>();
             Assert.Null(feature);
         }
     }

test/Microsoft.Azure.SignalR.Tests/ClientConnectionContextFacts.cs

@@ -229,7 +229,7 @@ public async void TestSendConnectionAsyncisOverwrittenWhenClientConnectionExiste
         public async void SetUserIdTest()
         {
             var connectionContext = new TestConnectionContext();
-            connectionContext.Features.Set<IServiceUserIdFeature>(new ServiceUserIdFeature("testUser"));
+            connectionContext.Features.Set(new ServiceUserIdFeature("testUser"));
 
             var hubConnectionContext = new HubConnectionContext(connectionContext, new(), NullLoggerFactory.Instance);
             var serviceLifetimeManager = MockLifetimeManager(new TestServiceConnectionManager<TestHub>());
@@ -248,6 +248,7 @@ public async void DoNotSetUserIdWithoutFeatureTest()
             await serviceLifetimeManager.OnConnectedAsync(hubConnectionContext);
 
             Assert.Null(hubConnectionContext.UserIdentifier);
+            Assert.Null(hubConnectionContext.Features.Get<ServiceUserIdFeature>());
         }
 
         private HubLifetimeManager<TestHub> MockLifetimeManager(IServiceConnectionManager<TestHub> serviceConnectionManager, IClientConnectionManager clientConnectionManager = null, IBlazorDetector blazorDetector = null)