Simplify WeakReferenceTests.

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit.Tests/WeakReferenceTests.cs

@@ -17,29 +17,29 @@ namespace ICSharpCode.AvalonEdit
 	public class WeakReferenceTests
 	{
 		[Test]
-		public void GCCallbackTest()
+		public void TextViewCanBeCollectedTest()
 		{
-			bool collectedTextView = false;
-			TextView textView = new TextViewWithGCCallback(delegate { collectedTextView = true; });
+			TextView textView = new TextView();
+			WeakReference wr = new WeakReference(textView);
 			textView = null;
 			GarbageCollect();
-			Assert.IsTrue(collectedTextView);
+			Assert.IsFalse(wr.IsAlive);
 		}
 		
 		[Test]
 		public void DocumentDoesNotHoldReferenceToTextView()
 		{
-			bool collectedTextView = false;
 			TextDocument textDocument = new TextDocument();
 			Assert.AreEqual(0, textDocument.LineTrackers.Count);
 			
-			TextView textView = new TextViewWithGCCallback(delegate { collectedTextView = true; });
+			TextView textView = new TextView();
+			WeakReference wr = new WeakReference(textView);
 			textView.Document = textDocument;
 			Assert.AreEqual(1, textDocument.LineTrackers.Count);
 			textView = null;
 			
 			GarbageCollect();
-			Assert.IsTrue(collectedTextView);
+			Assert.IsFalse(wr.IsAlive);
 			// document cannot immediately clear the line tracker
 			Assert.AreEqual(1, textDocument.LineTrackers.Count);
 			
@@ -52,15 +52,15 @@ namespace ICSharpCode.AvalonEdit
 		[Ignore]
 		public void DocumentDoesNotHoldReferenceToTextArea()
 		{
-			bool collectedTextArea = false;
 			TextDocument textDocument = new TextDocument();
 			
-			TextArea textArea = new TextAreaWithGCCallback(delegate { collectedTextArea = true; });
+			TextArea textArea = new TextArea();
+			WeakReference wr = new WeakReference(textArea);
 			textArea.Document = textDocument;
 			textArea = null;
 			
 			GarbageCollect();
-			Assert.IsTrue(collectedTextArea);
+			Assert.IsFalse(wr.IsAlive);
 			GC.KeepAlive(textDocument);
 		}
 		
@@ -68,40 +68,40 @@ namespace ICSharpCode.AvalonEdit
 		[Ignore]
 		public void DocumentDoesNotHoldReferenceToTextEditor()
 		{
-			bool collectedTextEditor = false;
 			TextDocument textDocument = new TextDocument();
 			
-			TextEditor textEditor = new TextEditorWithGCCallback(delegate { collectedTextEditor = true; });
+			TextEditor textEditor = new TextEditor();
+			WeakReference wr = new WeakReference(textEditor);
 			textEditor.Document = textDocument;
 			textEditor = null;
 			
 			GarbageCollect();
-			Assert.IsTrue(collectedTextEditor);
+			Assert.IsFalse(wr.IsAlive);
 			GC.KeepAlive(textDocument);
 		}
 		
 		[Test]
 		public void DocumentDoesNotHoldReferenceToLineMargin()
 		{
-			bool collectedTextView = false;
 			TextDocument textDocument = new TextDocument();
 			
-			DocumentDoesNotHoldReferenceToLineMargin_CreateMargin(textDocument, delegate { collectedTextView = true; });
+			WeakReference wr = DocumentDoesNotHoldReferenceToLineMargin_CreateMargin(textDocument);
 			
 			GarbageCollect();
-			Assert.IsTrue(collectedTextView);
+			Assert.IsFalse(wr.IsAlive);
 			GC.KeepAlive(textDocument);
 		}
 		
 		// using a method to ensure the local variables can be garbage collected after the method returns
-		void DocumentDoesNotHoldReferenceToLineMargin_CreateMargin(TextDocument textDocument, Action finalizeAction)
+		WeakReference DocumentDoesNotHoldReferenceToLineMargin_CreateMargin(TextDocument textDocument)
 		{
-			TextView textView = new TextViewWithGCCallback(finalizeAction) {
+			TextView textView = new TextView() {
 				Document = textDocument
 			};
 			LineNumberMargin margin = new LineNumberMargin() {
 				TextView = textView
 			};
+			return new WeakReference(textView);
 		}
 		
 		static void GarbageCollect()
@@ -110,50 +110,5 @@ namespace ICSharpCode.AvalonEdit
 			GC.Collect(GC.MaxGeneration, GCCollectionMode.Forced);
 			GC.WaitForPendingFinalizers();
 		}
-		
-		sealed class TextViewWithGCCallback : TextView
-		{
-			Action onFinalize;
-			
-			public TextViewWithGCCallback(Action onFinalize)
-			{
-				this.onFinalize = onFinalize;
-			}
-			
-			~TextViewWithGCCallback()
-			{
-				onFinalize();
-			}
-		}
-		
-		sealed class TextAreaWithGCCallback : TextArea
-		{
-			Action onFinalize;
-			
-			public TextAreaWithGCCallback(Action onFinalize)
-			{
-				this.onFinalize = onFinalize;
-			}
-			
-			~TextAreaWithGCCallback()
-			{
-				onFinalize();
-			}
-		}
-		
-		sealed class TextEditorWithGCCallback : TextEditor
-		{
-			Action onFinalize;
-			
-			public TextEditorWithGCCallback(Action onFinalize)
-			{
-				this.onFinalize = onFinalize;
-			}
-			
-			~TextEditorWithGCCallback()
-			{
-				onFinalize();
-			}
-		}
 	}
 }