fix

Author: BrennanConroy

src/libraries/System.Text.Json/src/Resources/Strings.resx

@@ -830,10 +830,13 @@
   <data name="DuplicatePropertiesNotAllowed_JsonPropertyInfo" xml:space="preserve">
     <value>Duplicate property '{0}' encountered during deserialization of type '{1}'.</value>
   </data>
-    <data name="DuplicatePropertiesNotAllowed_NameSpan" xml:space="preserve">
+  <data name="DuplicatePropertiesNotAllowed_NameSpan" xml:space="preserve">
     <value>Duplicate property '{0}' encountered during deserialization.</value>
   </data>
   <data name="DuplicatePropertiesNotAllowed" xml:space="preserve">
     <value>Duplicate properties not allowed during deserialization.</value>
   </data>
-</root>
+  <data name="PipeReaderCanceled" xml:space="preserve">
+    <value>PipeReader.ReadAsync was canceled.</value>
+  </data>
+</root>

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/JsonSerializer.Read.Pipe.cs

@@ -330,7 +330,7 @@ public static partial class JsonSerializer
                 ReadStack readStack = default;
                 readStack.Initialize(listTypeInfo, supportContinuation: true);
                 JsonReaderState jsonReaderState = new(readerOptions);
-                PipeReadBufferState bufferState = default;
+                PipeReadBufferState bufferState = new(utf8Json);
 
                 try
                 {

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/PipeReadBufferState.cs

@@ -60,9 +60,14 @@ public async ValueTask<PipeReadBufferState> ReadAsync(PipeReader utf8Json, Cance
             ReadResult readResult = await _utf8Json.ReadAtLeastAsync(minBufferSize, cancellationToken).ConfigureAwait(false);
 
             bufferState._sequence = readResult.Buffer;
-            bufferState._isFinalBlock = readResult.IsCompleted || readResult.IsCanceled;
+            bufferState._isFinalBlock = readResult.IsCompleted;
             bufferState.ProcessReadBytes();
 
+            if (readResult.IsCanceled)
+            {
+                ThrowHelper.ThrowOperationCanceledException_PipeReadCanceled();
+            }
+
             return bufferState;
         }
 

src/libraries/System.Text.Json/src/System/Text/Json/ThrowHelper.Serialization.cs

@@ -979,6 +979,12 @@ public static void ThrowOperationCanceledException_PipeWriteCanceled()
             throw new OperationCanceledException(SR.PipeWriterCanceled);
         }
 
+        [DoesNotReturn]
+        public static void ThrowOperationCanceledException_PipeReadCanceled()
+        {
+            throw new OperationCanceledException(SR.PipeReaderCanceled);
+        }
+
         [DoesNotReturn]
         public static void ThrowInvalidOperationException_PipeWriterDoesNotImplementUnflushedBytes(PipeWriter pipeWriter)
         {

src/libraries/System.Text.Json/tests/System.Text.Json.Tests/Serialization/Pipe.ReadTests.cs

@@ -94,7 +94,8 @@ public async Task CancelPendingReadThrows()
             Task readTask = Serializer.DeserializeWrapper<int>(pipe.Reader);
             pipe.Reader.CancelPendingRead();
 
-            await Assert.ThrowsAsync<JsonException>(async () => await readTask);
+            OperationCanceledException ex = await Assert.ThrowsAsync<OperationCanceledException>(async () => await readTask);
+            Assert.Equal("PipeReader.ReadAsync was canceled.", ex.Message);
 
             // Clean up
             pipe.Writer.Complete();