CSHARP-1375: Added tests for SemaphoreSlimRequest.

Author: rstam

src/MongoDB.Driver.Core.Tests/Core/Misc/SemaphoreSlimRequestTests.cs

@@ -0,0 +1,125 @@
+/* Copyright 2015 MongoDB Inc.
+*
+* 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.
+*/
+
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using FluentAssertions;
+using NUnit.Framework;
+
+namespace MongoDB.Driver.Core.Misc
+{
+    [TestFixture]
+    public class SemaphoreSlimRequestTests
+    {
+        // public methods
+        [Test]
+        public void constructor_should_initialize_instance_with_completed_task_when_semaphore_is_available()
+        {
+            var semaphore = new SemaphoreSlim(1);
+
+            var result = new SemaphoreSlimRequest(semaphore, CancellationToken.None);
+
+            result.Task.Status.Should().Be(TaskStatus.RanToCompletion);
+            semaphore.CurrentCount.Should().Be(0);
+        }
+
+        [Test]
+        public void constructor_should_initialize_instance_with_incompleted_task_when_semaphore_is_not_available()
+        {
+            var semaphore = new SemaphoreSlim(1);
+            semaphore.Wait();
+
+            var result = new SemaphoreSlimRequest(semaphore, CancellationToken.None);
+
+            result.Task.IsCompleted.Should().BeFalse();
+            semaphore.CurrentCount.Should().Be(0);
+        }
+
+        [Test]
+        public void constructor_should_throw_when_semaphore_is_null()
+        {
+            Action action = () => new SemaphoreSlimRequest(null, CancellationToken.None);
+
+            action.ShouldThrow<ArgumentNullException>().And.ParamName.Should().Be("semaphore");
+        }
+
+        [Test]
+        public void Dispose_should_cancel_pending_request()
+        {
+            var semaphore = new SemaphoreSlim(1);
+            semaphore.Wait();
+            var subject = new SemaphoreSlimRequest(semaphore, CancellationToken.None);
+
+            subject.Dispose();
+            semaphore.Release();
+
+            subject.Task.Status.Should().Be(TaskStatus.Canceled);
+            semaphore.CurrentCount.Should().Be(1);
+        }
+
+        [Test]
+        public void Dispose_should_release_semaphore()
+        {
+            var semaphore = new SemaphoreSlim(1);
+            var subject = new SemaphoreSlimRequest(semaphore, CancellationToken.None);
+
+            subject.Dispose();
+
+            semaphore.CurrentCount.Should().Be(1);
+        }
+
+        [Test]
+        public void Sempahore_should_not_be_released_when_cancellation_is_requested_after_semaphore_is_acquired()
+        {
+            var semaphore = new SemaphoreSlim(1);
+            var cancellationTokenSource = new CancellationTokenSource();
+            var subject = new SemaphoreSlimRequest(semaphore, cancellationTokenSource.Token);
+
+            cancellationTokenSource.Cancel();
+
+            semaphore.CurrentCount.Should().Be(0);
+        }
+
+        [Test]
+        public void Task_should_be_cancelled_when_cancellationToken_requests_cancellation()
+        {
+            var semaphore = new SemaphoreSlim(1);
+            var cancellationTokenSource = new CancellationTokenSource();
+            semaphore.Wait();
+            var subject = new SemaphoreSlimRequest(semaphore, cancellationTokenSource.Token);
+
+            cancellationTokenSource.Cancel();
+            semaphore.Release();
+
+            subject.Task.Status.Should().Be(TaskStatus.Canceled);
+            semaphore.CurrentCount.Should().Be(1);
+        }
+
+        [Test]
+        public void Task_should_be_completed_when_semaphore_becomes_available()
+        {
+            var semaphore = new SemaphoreSlim(1);
+            semaphore.Wait();
+            var subject = new SemaphoreSlimRequest(semaphore, CancellationToken.None);
+
+            semaphore.Release();
+            SpinWait.SpinUntil(() => subject.Task.IsCompleted, 100);
+
+            subject.Task.Status.Should().Be(TaskStatus.RanToCompletion);
+            semaphore.CurrentCount.Should().Be(0);
+        }
+    }
+}

src/MongoDB.Driver.Core.Tests/MongoDB.Driver.Core.Tests.csproj

@@ -60,6 +60,7 @@
     <Compile Include="Core\Connections\BinaryConnection_CommandEventTests.cs" />
     <Compile Include="Core\Events\EventAggregatorTests.cs" />
     <Compile Include="Core\Events\ReflectionEventSubscriberTests.cs" />
+    <Compile Include="Core\Misc\SemaphoreSlimRequestTests.cs" />
     <Compile Include="Core\Misc\StreamExtensionMethodsTests.cs" />
     <Compile Include="Core\Operations\AggregateToCollectionOperationTests.cs" />
     <Compile Include="Core\Operations\AggregateOperationTests.cs" />