add C# test demoing custom error details

src/csharp/Grpc.IntegrationTesting/CustomErrorDetailsTest.cs

@@ -0,0 +1,112 @@
+#region Copyright notice and license
+
+// Copyright 2015-2016 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Google.Protobuf;
+using Grpc.Core;
+using Grpc.Core.Utils;
+using Grpc.Testing;
+using NUnit.Framework;
+
+namespace Grpc.IntegrationTesting
+{
+    /// <summary>
+    /// Shows how to attach custom error details as a binary trailer.
+    /// </summary>
+    public class CustomErrorDetailsTest
+    {
+        const string DebugInfoTrailerName = "debug-info-bin";
+        const string ExceptionDetail = "Exception thrown on purpose.";
+        const string Host = "localhost";
+        Server server;
+        Channel channel;
+        TestService.TestServiceClient client;
+
+        [TestFixtureSetUp]
+        public void Init()
+        {
+            // Disable SO_REUSEPORT to prevent https://github.com/grpc/grpc/issues/10755
+            server = new Server(new[] { new ChannelOption(ChannelOptions.SoReuseport, 0) })
+            {
+                Services = { TestService.BindService(new CustomErrorDetailsTestServiceImpl()) },
+                Ports = { { Host, ServerPort.PickUnused, ServerCredentials.Insecure } }
+            };
+            server.Start();
+
+            channel = new Channel(Host, server.Ports.Single().BoundPort, ChannelCredentials.Insecure);
+            client = new TestService.TestServiceClient(channel);
+        }
+
+        [TestFixtureTearDown]
+        public void Cleanup()
+        {
+            channel.ShutdownAsync().Wait();
+            server.ShutdownAsync().Wait();
+        }
+
+        [Test]
+        public async Task UnaryCall()
+        {
+            var call = client.UnaryCallAsync(new SimpleRequest { ResponseSize = 10 });
+
+            try
+            {
+                await call.ResponseAsync;
+                Assert.Fail();
+            }
+            catch (RpcException e)
+            {
+                Assert.AreEqual(StatusCode.Unknown, e.Status.StatusCode);
+                var debugInfo = GetDebugInfo(call.GetTrailers());
+                Assert.AreEqual(debugInfo.Detail, ExceptionDetail);
+                Assert.IsNotEmpty(debugInfo.StackEntries);
+            }
+        }
+
+        private DebugInfo GetDebugInfo(Metadata trailers)
+        {
+            var entry = trailers.First((e) => e.Key == DebugInfoTrailerName);
+            return DebugInfo.Parser.ParseFrom(entry.ValueBytes);
+        }
+
+        private class CustomErrorDetailsTestServiceImpl : TestService.TestServiceBase
+        {
+            public override async Task<SimpleResponse> UnaryCall(SimpleRequest request, ServerCallContext context)
+            {
+                try
+                {
+                    throw new ArgumentException(ExceptionDetail);
+                }
+                catch (Exception e)
+                {
+                    // Fill debug info with some structured details about the failure.
+                    var debugInfo = new DebugInfo();
+                    debugInfo.Detail = e.Message;
+                    debugInfo.StackEntries.AddRange(e.StackTrace.Split(new[] { Environment.NewLine }, StringSplitOptions.None)); 
+                    context.ResponseTrailers.Add(DebugInfoTrailerName, debugInfo.ToByteArray());
+                    throw new RpcException(new Status(StatusCode.Unknown, "The handler threw exception."));
+                }
+            }
+        }
+    }
+}

src/csharp/generate_proto_csharp.sh

@@ -37,4 +37,4 @@ $PROTOC --plugin=$PLUGIN --csharp_out=$REFLECTION_DIR --grpc_out=$REFLECTION_DIR
 # don't match the package names. Setting -I to the correct value src/proto
 # breaks the code generation.
 $PROTOC --plugin=$PLUGIN --csharp_out=$TESTING_DIR --grpc_out=$TESTING_DIR \
-    -I . src/proto/grpc/testing/{control,empty,messages,metrics,payloads,services,stats,test}.proto 
+    -I . src/proto/grpc/testing/{control,echo_messages,empty,messages,metrics,payloads,services,stats,test}.proto

src/csharp/tests.json

@@ -42,6 +42,7 @@
     "Grpc.HealthCheck.Tests.HealthServiceImplTest"
   ],
   "Grpc.IntegrationTesting": [
+    "Grpc.IntegrationTesting.CustomErrorDetailsTest",
     "Grpc.IntegrationTesting.GeneratedClientTest",
     "Grpc.IntegrationTesting.GeneratedServiceBaseTest",
     "Grpc.IntegrationTesting.HistogramTest",