SignalR Allow returns from all single client proxies

- #41763 (comment)

Author: halter73

src/SignalR/server/Core/src/IHubClients`T.cs

@@ -14,7 +14,7 @@ public interface IHubClients<T>
     /// </summary>
     /// <param name="connectionId">The connection ID.</param>
     /// <returns>A client caller.</returns>
-    T Single(string connectionId) => throw new NotImplementedException();
+    T Single(string connectionId) => Client(connectionId);
 
     /// <summary>
     /// Gets a <typeparamref name="T" /> that can be used to invoke methods on all clients connected to the hub.

src/SignalR/server/Core/src/Internal/HubClients.cs

@@ -15,7 +15,7 @@ public HubClients(HubLifetimeManager<THub> lifetimeManager)
 
     public ISingleClientProxy Single(string connectionId)
     {
-        return new SingleClientProxyWithInvoke<THub>(_lifetimeManager, connectionId);
+        return new SingleClientProxy<THub>(_lifetimeManager, connectionId);
     }
 
     public IClientProxy All { get; }

src/SignalR/server/Core/src/Internal/HubClients`T.cs

@@ -17,7 +17,7 @@ public HubClients(HubLifetimeManager<THub> lifetimeManager)
 
     public T Single(string connectionId)
     {
-        return TypedClientBuilder<T>.Build(new SingleClientProxyWithInvoke<THub>(_lifetimeManager, connectionId));
+        return TypedClientBuilder<T>.Build(new SingleClientProxy<THub>(_lifetimeManager, connectionId));
     }
 
     public T AllExcept(IReadOnlyList<string> excludedConnectionIds)

src/SignalR/server/Core/src/Internal/Proxies.cs

@@ -122,23 +122,6 @@ public Task SendCoreAsync(string method, object?[] args, CancellationToken cance
     }
 }
 
-internal sealed class SingleClientProxy<THub> : IClientProxy where THub : Hub
-{
-    private readonly string _connectionId;
-    private readonly HubLifetimeManager<THub> _lifetimeManager;
-
-    public SingleClientProxy(HubLifetimeManager<THub> lifetimeManager, string connectionId)
-    {
-        _lifetimeManager = lifetimeManager;
-        _connectionId = connectionId;
-    }
-
-    public Task SendCoreAsync(string method, object?[] args, CancellationToken cancellationToken = default)
-    {
-        return _lifetimeManager.SendConnectionAsync(_connectionId, method, args, cancellationToken);
-    }
-}
-
 internal sealed class MultipleClientProxy<THub> : IClientProxy where THub : Hub
 {
     private readonly HubLifetimeManager<THub> _lifetimeManager;
@@ -156,12 +139,12 @@ public Task SendCoreAsync(string method, object?[] args, CancellationToken cance
     }
 }
 
-internal sealed class SingleClientProxyWithInvoke<THub> : ISingleClientProxy where THub : Hub
+internal sealed class SingleClientProxy<THub> : ISingleClientProxy where THub : Hub
 {
     private readonly string _connectionId;
     private readonly HubLifetimeManager<THub> _lifetimeManager;
 
-    public SingleClientProxyWithInvoke(HubLifetimeManager<THub> lifetimeManager, string connectionId)
+    public SingleClientProxy(HubLifetimeManager<THub> lifetimeManager, string connectionId)
     {
         _lifetimeManager = lifetimeManager;
         _connectionId = connectionId;

src/SignalR/server/SignalR/test/ClientProxyTests.cs

@@ -212,7 +212,7 @@ public async Task SingleClientProxyWithInvoke_ThrowsNotSupported()
     {
         var hubLifetimeManager = new EmptyHubLifetimeManager<FakeHub>();
 
-        var proxy = new SingleClientProxyWithInvoke<FakeHub>(hubLifetimeManager, "");
+        var proxy = new SingleClientProxy<FakeHub>(hubLifetimeManager, "");
         var ex = await Assert.ThrowsAsync<NotImplementedException>(async () => await proxy.InvokeAsync<int>("method")).DefaultTimeout();
         Assert.Equal("EmptyHubLifetimeManager`1 does not support client return values.", ex.Message);
     }