HubConnection implements IAsyncDisposable (#13179)

src/SignalR/clients/csharp/Client.Core/ref/Microsoft.AspNetCore.SignalR.Client.Core.netstandard2.0.cs

@@ -3,7 +3,7 @@
 
 namespace Microsoft.AspNetCore.SignalR.Client
 {
-    public partial class HubConnection
+    public partial class HubConnection : System.IAsyncDisposable
     {
         public static readonly System.TimeSpan DefaultHandshakeTimeout;
         public static readonly System.TimeSpan DefaultKeepAliveInterval;
@@ -19,7 +19,7 @@ namespace Microsoft.AspNetCore.SignalR.Client
         public event System.Func<string, System.Threading.Tasks.Task> Reconnected { add { } remove { } }
         public event System.Func<System.Exception, System.Threading.Tasks.Task> Reconnecting { add { } remove { } }
         [System.Diagnostics.DebuggerStepThroughAttribute]
-        public System.Threading.Tasks.Task DisposeAsync() { throw null; }
+        public System.Threading.Tasks.ValueTask DisposeAsync() { throw null; }
         [System.Diagnostics.DebuggerStepThroughAttribute]
         public System.Threading.Tasks.Task<object> InvokeCoreAsync(string methodName, System.Type returnType, object[] args, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) { throw null; }
         public System.IDisposable On(string methodName, System.Type[] parameterTypes, System.Func<object[], object, System.Threading.Tasks.Task> handler, object state) { throw null; }

src/SignalR/clients/csharp/Client.Core/ref/Microsoft.AspNetCore.SignalR.Client.Core.netstandard2.1.cs

@@ -3,7 +3,7 @@
 
 namespace Microsoft.AspNetCore.SignalR.Client
 {
-    public partial class HubConnection
+    public partial class HubConnection : System.IAsyncDisposable
     {
         public static readonly System.TimeSpan DefaultHandshakeTimeout;
         public static readonly System.TimeSpan DefaultKeepAliveInterval;
@@ -19,7 +19,7 @@ namespace Microsoft.AspNetCore.SignalR.Client
         public event System.Func<string, System.Threading.Tasks.Task> Reconnected { add { } remove { } }
         public event System.Func<System.Exception, System.Threading.Tasks.Task> Reconnecting { add { } remove { } }
         [System.Diagnostics.DebuggerStepThroughAttribute]
-        public System.Threading.Tasks.Task DisposeAsync() { throw null; }
+        public System.Threading.Tasks.ValueTask DisposeAsync() { throw null; }
         [System.Diagnostics.DebuggerStepThroughAttribute]
         public System.Threading.Tasks.Task<object> InvokeCoreAsync(string methodName, System.Type returnType, object[] args, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) { throw null; }
         public System.IDisposable On(string methodName, System.Type[] parameterTypes, System.Func<object[], object, System.Threading.Tasks.Task> handler, object state) { throw null; }

src/SignalR/clients/csharp/Client.Core/src/HubConnection.cs

@@ -22,7 +22,6 @@ using Microsoft.AspNetCore.SignalR.Internal;
 using Microsoft.AspNetCore.SignalR.Protocol;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.Abstractions;
-using Microsoft.Extensions.Options;
 
 namespace Microsoft.AspNetCore.SignalR.Client
 {
@@ -34,7 +33,7 @@ namespace Microsoft.AspNetCore.SignalR.Client
     /// Before hub methods can be invoked the connection must be started using <see cref="StartAsync"/>.
     /// Clean up a connection using <see cref="StopAsync"/> or <see cref="DisposeAsync"/>.
     /// </remarks>
-    public partial class HubConnection
+    public partial class HubConnection : IAsyncDisposable
     {
         public static readonly TimeSpan DefaultServerTimeout = TimeSpan.FromSeconds(30); // Server ping rate is 15 sec, this is 2 times that.
         public static readonly TimeSpan DefaultHandshakeTimeout = TimeSpan.FromSeconds(15);
@@ -292,8 +291,8 @@ namespace Microsoft.AspNetCore.SignalR.Client
         /// <summary>
         /// Disposes the <see cref="HubConnection"/>.
         /// </summary>
-        /// <returns>A <see cref="Task"/> that represents the asynchronous dispose.</returns>
+        /// <returns>A <see cref="ValueTask"/> that represents the asynchronous dispose.</returns>
-        public async Task DisposeAsync()
+        public async ValueTask DisposeAsync()
         {
             if (!_disposed)
             {
@@ -504,8 +503,16 @@ namespace Microsoft.AspNetCore.SignalR.Client
 
                 if (disposing)
                 {
-                    (_serviceProvider as IDisposable)?.Dispose();
+                    // Must set this before calling DisposeAsync because the service provider has a reference to the HubConnection and will try to dispose it again
                     _disposed = true;
+                    if (_serviceProvider is IAsyncDisposable asyncDispose)
+                    {
+                        await asyncDispose.DisposeAsync();
+                    }
+                    else
+                    {
+                        (_serviceProvider as IDisposable)?.Dispose();
+                    }
                 }
             }
             finally

src/SignalR/clients/csharp/Client/test/UnitTests/HubConnectionTests.cs

@@ -414,6 +414,17 @@ namespace Microsoft.AspNetCore.SignalR.Client.Tests
             }
         }
 
+        [Fact]
+        public async Task CanAwaitUsingHubConnection()
+        {
+            using (StartVerifiableLog())
+            {
+                var connection = new TestConnection();
+                await using var hubConnection = CreateHubConnection(connection, loggerFactory: LoggerFactory);
+                await hubConnection.StartAsync().OrTimeout();
+            }
+        }
+
         private class SampleObject
         {
             public SampleObject(string foo, int bar)