Exiting SSE transport receive loop when transport is stopping

Fixes: #650

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

@@ -71,25 +71,26 @@ namespace Microsoft.AspNetCore.Sockets.Client
             var response = await _httpClient.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, cancellationToken);
 
             var stream = await response.Content.ReadAsStreamAsync();
-
+            var pipelineReader = stream.AsPipelineReader(cancellationToken);
-            var pipelineReader = stream.AsPipelineReader();
+            var readCancellationRegistration = cancellationToken.Register(
+                reader => ((IPipeReader)reader).CancelPendingRead(), pipelineReader);
             try
             {
                 while (true)
                 {
                     var result = await pipelineReader.ReadAsync();
                     var input = result.Buffer;
+                    if (result.IsCancelled || (input.IsEmpty && result.IsCompleted))
+                    {
+                        _logger.LogDebug("Server-Sent Event Stream ended");
+                        break;
+                    }
+
                     var consumed = input.Start;
                     var examined = input.End;
 
                     try
                     {
-                        if (input.IsEmpty && result.IsCompleted)
-                        {
-                            _logger.LogDebug("Server-Sent Event Stream ended");
-                            break;
-                        }
-
                         var parseResult = _parser.ParseMessage(input, out consumed, out examined, out var buffer);
 
                         switch (parseResult)
@@ -114,6 +115,7 @@ namespace Microsoft.AspNetCore.Sockets.Client
             }
             finally
             {
+                readCancellationRegistration.Dispose();
                 _transportCts.Cancel();
                 stream.Dispose();
             }

test/Microsoft.AspNetCore.SignalR.Client.Tests/LongPollingTransportTests.cs

@@ -37,7 +37,7 @@ namespace Microsoft.AspNetCore.Client.Tests
 
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
             {
-                var longPollingTransport = new LongPollingTransport(httpClient, new LoggerFactory());
+                var longPollingTransport = new LongPollingTransport(httpClient);
 
                 try
                 {
@@ -74,7 +74,7 @@ namespace Microsoft.AspNetCore.Client.Tests
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
             {
 
-                var longPollingTransport = new LongPollingTransport(httpClient, new LoggerFactory());
+                var longPollingTransport = new LongPollingTransport(httpClient);
                 try
                 {
                     var connectionToTransport = Channel.CreateUnbounded<SendMessage>();
@@ -127,7 +127,7 @@ namespace Microsoft.AspNetCore.Client.Tests
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
             {
 
-                var longPollingTransport = new LongPollingTransport(httpClient, new LoggerFactory());
+                var longPollingTransport = new LongPollingTransport(httpClient);
                 try
                 {
                     var connectionToTransport = Channel.CreateUnbounded<SendMessage>();
@@ -163,7 +163,7 @@ namespace Microsoft.AspNetCore.Client.Tests
 
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
             {
-                var longPollingTransport = new LongPollingTransport(httpClient, new LoggerFactory());
+                var longPollingTransport = new LongPollingTransport(httpClient);
                 try
                 {
                     var connectionToTransport = Channel.CreateUnbounded<SendMessage>();
@@ -199,7 +199,7 @@ namespace Microsoft.AspNetCore.Client.Tests
 
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
             {
-                var longPollingTransport = new LongPollingTransport(httpClient, new LoggerFactory());
+                var longPollingTransport = new LongPollingTransport(httpClient);
                 try
                 {
                     var connectionToTransport = Channel.CreateUnbounded<SendMessage>();
@@ -240,7 +240,7 @@ namespace Microsoft.AspNetCore.Client.Tests
 
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
             {
-                var longPollingTransport = new LongPollingTransport(httpClient, new LoggerFactory());
+                var longPollingTransport = new LongPollingTransport(httpClient);
                 try
                 {
                     var connectionToTransport = Channel.CreateUnbounded<SendMessage>();
@@ -289,7 +289,7 @@ namespace Microsoft.AspNetCore.Client.Tests
 
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
             {
-                var longPollingTransport = new LongPollingTransport(httpClient, new LoggerFactory());
+                var longPollingTransport = new LongPollingTransport(httpClient);
                 try
                 {
                     var connectionToTransport = Channel.CreateUnbounded<SendMessage>();
@@ -347,7 +347,7 @@ namespace Microsoft.AspNetCore.Client.Tests
 
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
             {
-                var longPollingTransport = new LongPollingTransport(httpClient, new LoggerFactory());
+                var longPollingTransport = new LongPollingTransport(httpClient);
                 try
                 {
                     var connectionToTransport = Channel.CreateUnbounded<SendMessage>();

test/Microsoft.AspNetCore.SignalR.Client.Tests/ServerSentEventsTransportTests.cs

@@ -0,0 +1,65 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.IO;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+using System.Threading.Tasks.Channels;
+using Microsoft.AspNetCore.SignalR.Tests.Common;
+using Microsoft.AspNetCore.Sockets.Client;
+using Microsoft.AspNetCore.Sockets.Internal;
+using Moq;
+using Moq.Protected;
+using Xunit;
+
+namespace Microsoft.AspNetCore.SignalR.Client.Tests
+{
+    public class ServerSentEventsTransportTests
+    {
+        [Fact]
+        public async Task CanStartStopSSETransport()
+        {
+            var eventStreamTcs = new TaskCompletionSource<object>();
+            var copyToAsyncTcs = new TaskCompletionSource<int>();
+
+            var mockHttpHandler = new Mock<HttpMessageHandler>();
+            mockHttpHandler.Protected()
+                .Setup<Task<HttpResponseMessage>>("SendAsync", ItExpr.IsAny<HttpRequestMessage>(), ItExpr.IsAny<CancellationToken>())
+                .Returns<HttpRequestMessage, CancellationToken>(async (request, cancellationToken) =>
+                {
+                    await Task.Yield();
+                    // Receive loop started - allow stopping the transport
+                    eventStreamTcs.SetResult(null);
+
+                    // returns unfinished task to block pipelines
+                    var mockStream = new Mock<Stream>();
+                    mockStream
+                        .Setup(s => s.CopyToAsync(It.IsAny<Stream>(), It.IsAny<int>(), It.IsAny<CancellationToken>()))
+                        .Returns(copyToAsyncTcs.Task);
+                    return new HttpResponseMessage { Content = new StreamContent(mockStream.Object) };
+                });
+
+            try
+            {
+                using (var httpClient = new HttpClient(mockHttpHandler.Object))
+                {
+                    var sseTransport = new ServerSentEventsTransport(httpClient);
+                    var connectionToTransport = Channel.CreateUnbounded<SendMessage>();
+                    var transportToConnection = Channel.CreateUnbounded<byte[]>();
+                    var channelConnection = new ChannelConnection<SendMessage, byte[]>(connectionToTransport, transportToConnection);
+                    await sseTransport.StartAsync(new Uri("http://fakeuri.org"), channelConnection).OrTimeout();
+
+                    await eventStreamTcs.Task.OrTimeout();
+                    await sseTransport.StopAsync().OrTimeout();
+                    await sseTransport.Running.OrTimeout();
+                }
+            }
+            finally
+            {
+                copyToAsyncTcs.SetResult(0);
+            }
+        }
+    }
+}

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

@@ -249,7 +249,7 @@ namespace Microsoft.AspNetCore.SignalR.Tests
             }
         }
 
-        public static IEnumerable<object[]> TransportTypes() =>
+        public static IEnumerable<object[]> TransportTypes =>
             new[]
             {
                 new object[] { TransportType.WebSockets },