From 3f846d93b8c36fa15c426d61b93041dcc884e17d Mon Sep 17 00:00:00 2001
From: Brennan <brennan@Brennans-MacBook-Air.local>
Date: Tue, 23 Apr 2019 10:08:12 -0700
Subject: [PATCH] Fix channel stream cancellation

---
 src/SignalR/common/Shared/AsyncEnumerableAdapters.cs       | 7 +++++--
 .../server/Core/src/Internal/HubMethodDescriptor.cs        | 6 +++---
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/SignalR/common/Shared/AsyncEnumerableAdapters.cs b/src/SignalR/common/Shared/AsyncEnumerableAdapters.cs
index a0951b3e59..6ebd1dcb25 100644
--- a/src/SignalR/common/Shared/AsyncEnumerableAdapters.cs
+++ b/src/SignalR/common/Shared/AsyncEnumerableAdapters.cs
@@ -23,9 +23,12 @@ namespace Microsoft.AspNetCore.SignalR.Internal
             return new CancelableTypedAsyncEnumerable<T>(asyncEnumerable, cts);
         }
 
-        public static IAsyncEnumerable<object> MakeCancelableAsyncEnumerableFromChannel<T>(ChannelReader<T> channel, CancellationToken cancellationToken = default)
+        public static async IAsyncEnumerable<object> MakeAsyncEnumerableFromChannel<T>(ChannelReader<T> channel, CancellationToken cancellationToken = default)
         {
-            return MakeCancelableAsyncEnumerable(channel.ReadAllAsync(), cancellationToken);
+            await foreach (var item in channel.ReadAllAsync(cancellationToken))
+            {
+                yield return item;
+            }
         }
 
         private class CancelableTypedAsyncEnumerable<TResult> : IAsyncEnumerable<TResult>
diff --git a/src/SignalR/server/Core/src/Internal/HubMethodDescriptor.cs b/src/SignalR/server/Core/src/Internal/HubMethodDescriptor.cs
index 205c1ced72..c6ad4fec10 100644
--- a/src/SignalR/server/Core/src/Internal/HubMethodDescriptor.cs
+++ b/src/SignalR/server/Core/src/Internal/HubMethodDescriptor.cs
@@ -19,9 +19,9 @@ namespace Microsoft.AspNetCore.SignalR.Internal
             .GetRuntimeMethods()
             .Single(m => m.Name.Equals(nameof(AsyncEnumerableAdapters.MakeCancelableAsyncEnumerable)) && m.IsGenericMethod);
 
-        private static readonly MethodInfo MakeCancelableAsyncEnumerableFromChannelMethod = typeof(AsyncEnumerableAdapters)
+        private static readonly MethodInfo MakeAsyncEnumerableFromChannelMethod = typeof(AsyncEnumerableAdapters)
             .GetRuntimeMethods()
-            .Single(m => m.Name.Equals(nameof(AsyncEnumerableAdapters.MakeCancelableAsyncEnumerableFromChannel)) && m.IsGenericMethod);
+            .Single(m => m.Name.Equals(nameof(AsyncEnumerableAdapters.MakeAsyncEnumerableFromChannel)) && m.IsGenericMethod);
 
         private readonly MethodInfo _makeCancelableEnumerableMethodInfo;
         private Func<object, CancellationToken, IAsyncEnumerable<object>> _makeCancelableEnumerable;
@@ -53,7 +53,7 @@ namespace Microsoft.AspNetCore.SignalR.Internal
                 if (openReturnType == typeof(ChannelReader<>))
                 {
                     StreamReturnType = returnType.GetGenericArguments()[0];
-                    _makeCancelableEnumerableMethodInfo = MakeCancelableAsyncEnumerableFromChannelMethod;
+                    _makeCancelableEnumerableMethodInfo = MakeAsyncEnumerableFromChannelMethod;
                     break;
                 }
             }