SSE StopAsync should ignore exception (handled elsewhere) (#708)

src/Microsoft.AspNetCore.Sockets.Client.Http/ServerSentEventsTransport.cs

@@ -140,7 +140,15 @@ namespace Microsoft.AspNetCore.Sockets.Client
             _logger.TransportStopping(_connectionId);
             _transportCts.Cancel();
             _application.Out.TryComplete();
-            await Running;
+
+            try
+            {
+                await Running;
+            }
+            catch
+            {
+                // exceptions have been handled in the Running task continuation by closing the channel with the exception
+            }
         }
     }
 }

test/Microsoft.AspNetCore.SignalR.Tests/EndToEndTests.cs

@@ -43,7 +43,7 @@ namespace Microsoft.AspNetCore.SignalR.Tests
         }
 
         [Fact]
-        public async Task CanStartConnectionUsingDefaultTransport()
+        public async Task CanStartAndStopConnectionUsingDefaultTransport()
         {
             var url = _serverFixture.BaseUrl + "/echo";
             // The test should connect to the server using WebSockets transport on Windows 8 and newer.
@@ -53,6 +53,17 @@ namespace Microsoft.AspNetCore.SignalR.Tests
             await connection.DisposeAsync().OrTimeout();
         }
 
+        [Theory]
+        [MemberData(nameof(TransportTypes))]
+        public async Task CanStartAndStopConnectionUsingGivenTransport(TransportType transportType)
+        {
+            var url = _serverFixture.BaseUrl + "/echo";
+            // When WebSockets is attempted to be used on Windows 7/2008R2 it will instead use ServerSentEvents
+            var connection = new HttpConnection(new Uri(url), transportType);
+            await connection.StartAsync().OrTimeout();
+            await connection.DisposeAsync().OrTimeout();
+        }
+
         [ConditionalFact]
         [OSSkipCondition(OperatingSystems.Windows, WindowsVersions.Win7, WindowsVersions.Win2008R2, SkipReason = "No WebSockets Client for this platform")]
         public async Task WebSocketsTest()