Erweiterung der UnitTests und kleinere Fixes

AMWD.Common.Tests/Extensions/ReaderWriterLockSlimExtensionsTests.cs

@@ -0,0 +1,98 @@
+using System.Threading;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace AMWD.Common.Tests.Extensions
+{
+	[TestClass]
+	public class ReaderWriterLockSlimExtensionsTests
+	{
+		[TestMethod]
+		public void ShouldEnterReadLock()
+		{
+			// arrange
+			var rwLock = new ReaderWriterLockSlim();
+
+			// act
+			using var disposable = rwLock.GetReadLock();
+
+			// assert
+			Assert.IsNotNull(disposable);
+			Assert.IsTrue(rwLock.IsReadLockHeld);
+			Assert.IsFalse(rwLock.IsUpgradeableReadLockHeld);
+			Assert.IsFalse(rwLock.IsWriteLockHeld);
+		}
+
+		[TestMethod]
+		public void ShouldEnterUpgradeableReadLock()
+		{
+			// arrange
+			var rwLock = new ReaderWriterLockSlim();
+
+			// act
+			using var disposable = rwLock.GetUpgradeableReadLock();
+
+			// assert
+			Assert.IsNotNull(disposable);
+			Assert.IsFalse(rwLock.IsReadLockHeld);
+			Assert.IsTrue(rwLock.IsUpgradeableReadLockHeld);
+			Assert.IsFalse(rwLock.IsWriteLockHeld);
+		}
+
+		[TestMethod]
+		public void ShouldEnterWriteLock()
+		{
+			// arrange
+			var rwLock = new ReaderWriterLockSlim();
+
+			// act
+			using var disposable = rwLock.GetWriteLock();
+
+			// assert
+			Assert.IsNotNull(disposable);
+			Assert.IsFalse(rwLock.IsReadLockHeld);
+			Assert.IsFalse(rwLock.IsUpgradeableReadLockHeld);
+			Assert.IsTrue(rwLock.IsWriteLockHeld);
+		}
+
+		[TestMethod]
+		public void ShouldNotAllowWriteLockAfterReadLock()
+		{
+			// arrange
+			var rwLock = new ReaderWriterLockSlim();
+
+			// act
+			using var disposableRead = rwLock.GetReadLock();
+			try
+			{
+				using var disposaleWrite = rwLock.GetWriteLock();
+				Assert.Fail();
+			}
+			catch (LockRecursionException)
+			{ }
+
+			// assert
+			Assert.IsNotNull(disposableRead);
+			Assert.IsTrue(rwLock.IsReadLockHeld);
+			Assert.IsFalse(rwLock.IsUpgradeableReadLockHeld);
+			Assert.IsFalse(rwLock.IsWriteLockHeld);
+		}
+
+		[TestMethod]
+		public void ShouldAllowWriteLockAfterUpgradeableReadLock()
+		{
+			// arrange
+			var rwLock = new ReaderWriterLockSlim();
+
+			// act
+			using var disposableRead = rwLock.GetUpgradeableReadLock();
+			using var disposaleWrite = rwLock.GetWriteLock();
+
+			// assert
+			Assert.IsNotNull(disposableRead);
+			Assert.IsNotNull(disposaleWrite);
+			Assert.IsFalse(rwLock.IsReadLockHeld);
+			Assert.IsTrue(rwLock.IsUpgradeableReadLockHeld);
+			Assert.IsTrue(rwLock.IsWriteLockHeld);
+		}
+	}
+}