From b2dba8d9059267565d2331ad887a57e53d940ea6 Mon Sep 17 00:00:00 2001
From: Brennan <brecon@microsoft.com>
Date: Tue, 27 Oct 2020 17:09:58 -0700
Subject: [PATCH] Throw when reader is completed with an exception (#43776)

---
 .../src/System/IO/Pipelines/Pipe.cs                |  2 +-
 .../tests/PipeReaderWriterFacts.cs                 | 46 +++++++++++++++-------
 2 files changed, 33 insertions(+), 15 deletions(-)

diff --git a/src/libraries/System.IO.Pipelines/src/System/IO/Pipelines/Pipe.cs b/src/libraries/System.IO.Pipelines/src/System/IO/Pipelines/Pipe.cs
index 90964cd..842abf6 100644
--- a/src/libraries/System.IO.Pipelines/src/System/IO/Pipelines/Pipe.cs
+++ b/src/libraries/System.IO.Pipelines/src/System/IO/Pipelines/Pipe.cs
@@ -960,7 +960,7 @@ namespace System.IO.Pipelines
                 ThrowHelper.ThrowInvalidOperationException_NoWritingAllowed();
             }
 
-            if (_readerCompletion.IsCompleted)
+            if (_readerCompletion.IsCompletedOrThrow())
             {
                 return new ValueTask<FlushResult>(new FlushResult(isCanceled: false, isCompleted: true));
             }
diff --git a/src/libraries/System.IO.Pipelines/tests/PipeReaderWriterFacts.cs b/src/libraries/System.IO.Pipelines/tests/PipeReaderWriterFacts.cs
index 61126ab..987c239 100644
--- a/src/libraries/System.IO.Pipelines/tests/PipeReaderWriterFacts.cs
+++ b/src/libraries/System.IO.Pipelines/tests/PipeReaderWriterFacts.cs
@@ -4,6 +4,7 @@
 using System.Buffers;
 using System.Collections.Generic;
 using System.Linq;
+using System.Runtime.CompilerServices;
 using System.Text;
 using System.Text.RegularExpressions;
 using System.Threading;
@@ -199,37 +200,54 @@ namespace System.IO.Pipelines.Tests
             Assert.Equal(" World", Encoding.ASCII.GetString(worldBytes));
         }
 
-        [Fact]
-        public async Task ReadAsync_ThrowsIfWriterCompletedWithException()
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        void ThrowTestException(Exception ex, Action<Exception> catchAction)
         {
-            void ThrowTestException()
+            try
             {
-                try
-                {
-                    throw new InvalidOperationException("Writer exception");
-                }
-                catch (Exception e)
-                {
-                    _pipe.Writer.Complete(e);
-                }
+                throw ex;
+            }
+            catch (Exception e)
+            {
+                catchAction(e);
             }
+        }
 
-            ThrowTestException();
+        [Fact]
+        public async Task ReadAsync_ThrowsIfWriterCompletedWithException()
+        {
+            ThrowTestException(new InvalidOperationException("Writer exception"), e => _pipe.Writer.Complete(e));
 
             InvalidOperationException invalidOperationException =
                 await Assert.ThrowsAsync<InvalidOperationException>(async () => await _pipe.Reader.ReadAsync());
 
             Assert.Equal("Writer exception", invalidOperationException.Message);
-            Assert.Contains("ThrowTestException", invalidOperationException.StackTrace);
+            Assert.Contains(nameof(ThrowTestException), invalidOperationException.StackTrace);
 
             invalidOperationException = await Assert.ThrowsAsync<InvalidOperationException>(async () => await _pipe.Reader.ReadAsync());
             Assert.Equal("Writer exception", invalidOperationException.Message);
-            Assert.Contains("ThrowTestException", invalidOperationException.StackTrace);
+            Assert.Contains(nameof(ThrowTestException), invalidOperationException.StackTrace);
 
             Assert.Single(Regex.Matches(invalidOperationException.StackTrace, "Pipe.GetReadResult"));
         }
 
         [Fact]
+        public async Task WriteAsync_ThrowsIfReaderCompletedWithException()
+        {
+            ThrowTestException(new InvalidOperationException("Reader exception"), e => _pipe.Reader.Complete(e));
+
+            InvalidOperationException invalidOperationException =
+                await Assert.ThrowsAsync<InvalidOperationException>(async () => await _pipe.Writer.WriteAsync(new byte[1]));
+
+            Assert.Equal("Reader exception", invalidOperationException.Message);
+            Assert.Contains(nameof(ThrowTestException), invalidOperationException.StackTrace);
+
+            invalidOperationException = await Assert.ThrowsAsync<InvalidOperationException>(async () => await _pipe.Writer.WriteAsync(new byte[1]));
+            Assert.Equal("Reader exception", invalidOperationException.Message);
+            Assert.Contains(nameof(ThrowTestException), invalidOperationException.StackTrace);
+        }
+
+        [Fact]
         public async Task ReaderShouldNotGetUnflushedBytes()
         {
             // Write 10 and flush
-- 
2.7.4