Replace StringBuilder with TextWriter in JsonFormatter

1 files changed, 9 insertions, 0 deletions

diff --git a/csharp/src/Google.Protobuf.Test/GeneratedMessageTest.cs b/csharp/src/Google.Protobuf.Test/GeneratedMessageTest.cs
index 67069954..5c2a052b 100644
--- a/csharp/src/Google.Protobuf.Test/GeneratedMessageTest.cs
+++ b/csharp/src/Google.Protobuf.Test/GeneratedMessageTest.cs
@@ -710,5 +710,14 @@ namespace Google.Protobuf
             Assert.AreEqual("{ \"singleForeignMessage\": { \"c\": 16, \"@cInHex\": \"10\" } }", message.ToString());

             Assert.AreEqual("{ \"singleForeignMessage\": { \"c\": 16 } }", JsonFormatter.Default.Format(message));

         }

+

+        [Test]

+        public void CustomDiagnosticMessage_DirectToTextWriterCall()

+        {

+            var message = new ForeignMessage { C = 31 };

+            var writer = new StringWriter();

+            JsonFormatter.Default.Format(message, writer);

+            Assert.AreEqual("{ \"c\": 31 }", writer.ToString());

+        }

     }

 }