demonstrate testability of server-side impl classes

src/csharp/Grpc.Examples.Tests/MathServiceImplTestabilityTest.cs

@@ -0,0 +1,47 @@
+#region Copyright notice and license
+
+// Copyright 2018 The 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.Threading;
+using System.Threading.Tasks;
+using Grpc.Core;
+using Grpc.Core.Testing;
+using Grpc.Core.Utils;
+using NUnit.Framework;
+
+namespace Math.Tests
+{
+    /// <summary>
+    /// Demonstrates how to unit test implementations of generated server stubs.
+    /// </summary>
+    public class MathServiceImplTestabilityTest
+    {
+        [Test]
+        public async Task ServerCallImplIsTestable()
+        {
+            var mathImpl = new MathServiceImpl();
+
+            // Use a factory method provided by Grpc.Core.Testing.TestServerCallContext to create an instance of server call context.
+            // This allows testing even those server-side implementations that rely on the contents of ServerCallContext.
+            var fakeServerCallContext = TestServerCallContext.Create("fooMethod", null, DateTime.UtcNow.AddHours(1), new Metadata(), CancellationToken.None, "127.0.0.1", null, null, (metadata) => TaskUtils.CompletedTask, () => new WriteOptions(), (writeOptions) => { });
+            var response = await mathImpl.Div(new DivArgs { Dividend = 10, Divisor = 2 }, fakeServerCallContext);
+            Assert.AreEqual(5, response.Quotient);
+            Assert.AreEqual(0, response.Remainder);
+        }
+    }
+}

src/csharp/tests.json

@@ -42,7 +42,8 @@
   ],
   "Grpc.Examples.Tests": [
     "Math.Tests.MathClientMockableTest",
-    "Math.Tests.MathClientServerTest"
+    "Math.Tests.MathClientServerTest",
+    "Math.Tests.MathServiceImplTestabilityTest"
   ],
   "Grpc.HealthCheck.Tests": [
     "Grpc.HealthCheck.Tests.HealthClientServerTest",