Fix preview handlers failing unit tests in CI (#1856)

* Enable Unit tests for PreviewPane Test Assemblies in CI

* Added Preview handlers unit tests project back

* throw for Svg to debug tests

* Removed failing test

* Removed throw statement

* Added MD unitests in yml

* Run ui tests on STA thread

* Throw svg to debug failing tests

* Updated test adaptor

* Removed failing test to validate CI

* throw svg failing test with full stack trace

* Check if mock stream is causing the issue

* narrow down the failing tests code - 1

* narrow down the failing tests code -2

* dispose all controls

* Restore SVg preview control

* Update test adaptor and dependency to latest

src/modules/previewpane/PreviewPaneUnitTests/MarkdownPreviewHandlerTest.cs

@@ -18,93 +18,99 @@ namespace PreviewPaneUnitTests
         public void MarkdownPreviewHandlerControl__AddsBrowserToForm_WhenDoPreviewIsCalled()
         {
             // Arrange 
-            MarkdownPreviewHandlerControl markdownPreviewHandlerControl = new MarkdownPreviewHandlerControl();
+            using (var markdownPreviewHandlerControl = new MarkdownPreviewHandlerControl()) 
+            {
+                // Act
+                markdownPreviewHandlerControl.DoPreview<string>("HelperFiles/MarkdownWithExternalImage.txt");
 
-            // Act
-            markdownPreviewHandlerControl.DoPreview<string>("HelperFiles/MarkdownWithExternalImage.txt");
-
-            // Assert
-            Assert.AreEqual(markdownPreviewHandlerControl.Controls.Count, 2);
-            Assert.IsInstanceOfType(markdownPreviewHandlerControl.Controls[0], typeof(WebBrowserExt));
+                // Assert
+                Assert.AreEqual(markdownPreviewHandlerControl.Controls.Count, 2);
+                Assert.IsInstanceOfType(markdownPreviewHandlerControl.Controls[0], typeof(WebBrowserExt));
+            }
         }
 
         [TestMethod]
         public void MarkdownPreviewHandlerControl__AddsInfoBarToFormIfExternalImageLinkPresent_WhenDoPreviewIsCalled()
         {
             // Arrange 
-            MarkdownPreviewHandlerControl markdownPreviewHandlerControl = new MarkdownPreviewHandlerControl();
+            using (var markdownPreviewHandlerControl = new MarkdownPreviewHandlerControl()) 
+            {
+                // Act
+                markdownPreviewHandlerControl.DoPreview<string>("HelperFiles/MarkdownWithExternalImage.txt");
 
-            // Act
-            markdownPreviewHandlerControl.DoPreview<string>("HelperFiles/MarkdownWithExternalImage.txt");
-
-            // Assert
-            Assert.AreEqual(markdownPreviewHandlerControl.Controls.Count, 2);
-            Assert.IsInstanceOfType(markdownPreviewHandlerControl.Controls[1], typeof(RichTextBox));
+                // Assert
+                Assert.AreEqual(markdownPreviewHandlerControl.Controls.Count, 2);
+                Assert.IsInstanceOfType(markdownPreviewHandlerControl.Controls[1], typeof(RichTextBox));
+            }
         }
 
         [TestMethod]
         public void MarkdownPreviewHandlerControl__AddsInfoBarToFormIfHTMLImageTagIsPresent_WhenDoPreviewIsCalled()
         {
             // Arrange 
-            MarkdownPreviewHandlerControl markdownPreviewHandlerControl = new MarkdownPreviewHandlerControl();
+            using (var markdownPreviewHandlerControl = new MarkdownPreviewHandlerControl())
+            {
+                // Act
+                markdownPreviewHandlerControl.DoPreview<string>("HelperFiles/MarkdownWithHTMLImageTag.txt");
 
-            // Act
-            markdownPreviewHandlerControl.DoPreview<string>("HelperFiles/MarkdownWithHTMLImageTag.txt");
-
-            // Assert
-            Assert.AreEqual(markdownPreviewHandlerControl.Controls.Count, 2);
-            Assert.IsInstanceOfType(markdownPreviewHandlerControl.Controls[1], typeof(RichTextBox));
+                // Assert
+                Assert.AreEqual(markdownPreviewHandlerControl.Controls.Count, 2);
+                Assert.IsInstanceOfType(markdownPreviewHandlerControl.Controls[1], typeof(RichTextBox));
+            }
         }
 
         [TestMethod]
         public void MarkdownPreviewHandlerControl__DoesNotAddInfoBarToFormIfExternalImageLinkNotPresent_WhenDoPreviewIsCalled()
         {
             // Arrange 
-            MarkdownPreviewHandlerControl markdownPreviewHandlerControl = new MarkdownPreviewHandlerControl();
+            using (var markdownPreviewHandlerControl = new MarkdownPreviewHandlerControl()) 
+            {
+                // Act
+                markdownPreviewHandlerControl.DoPreview<string>("HelperFiles/MarkdownWithScript.txt");
 
-            // Act
-            markdownPreviewHandlerControl.DoPreview<string>("HelperFiles/MarkdownWithScript.txt");
-
-            // Assert
-            Assert.AreEqual(markdownPreviewHandlerControl.Controls.Count, 1);
-            Assert.IsInstanceOfType(markdownPreviewHandlerControl.Controls[0], typeof(WebBrowserExt));
+                // Assert
+                Assert.AreEqual(markdownPreviewHandlerControl.Controls.Count, 1);
+                Assert.IsInstanceOfType(markdownPreviewHandlerControl.Controls[0], typeof(WebBrowserExt));
+            }
         }
 
         [TestMethod]
         public void MarkdownPreviewHandlerControl__UpdatesWebBrowserSettings_WhenDoPreviewIsCalled()
         {
             // Arrange 
-            MarkdownPreviewHandlerControl markdownPreviewHandlerControl = new MarkdownPreviewHandlerControl();
+            using (var markdownPreviewHandlerControl = new MarkdownPreviewHandlerControl())
+            {
+                // Act
+                markdownPreviewHandlerControl.DoPreview<string>("HelperFiles/MarkdownWithExternalImage.txt");
 
-            // Act
-            markdownPreviewHandlerControl.DoPreview<string>("HelperFiles/MarkdownWithExternalImage.txt");
-
-            // Assert
-            Assert.IsInstanceOfType(markdownPreviewHandlerControl.Controls[0], typeof(WebBrowserExt));
-            Assert.IsNotNull(((WebBrowser)markdownPreviewHandlerControl.Controls[0]).DocumentText);
-            Assert.AreEqual(((WebBrowser)markdownPreviewHandlerControl.Controls[0]).Dock, DockStyle.Fill);
-            Assert.AreEqual(((WebBrowser)markdownPreviewHandlerControl.Controls[0]).IsWebBrowserContextMenuEnabled, false);
-            Assert.AreEqual(((WebBrowser)markdownPreviewHandlerControl.Controls[0]).ScriptErrorsSuppressed, true);
-            Assert.AreEqual(((WebBrowser)markdownPreviewHandlerControl.Controls[0]).ScrollBarsEnabled, true);
-            Assert.AreEqual(((WebBrowser)markdownPreviewHandlerControl.Controls[0]).AllowNavigation, false);
+                // Assert
+                Assert.IsInstanceOfType(markdownPreviewHandlerControl.Controls[0], typeof(WebBrowserExt));
+                Assert.IsNotNull(((WebBrowser)markdownPreviewHandlerControl.Controls[0]).DocumentText);
+                Assert.AreEqual(((WebBrowser)markdownPreviewHandlerControl.Controls[0]).Dock, DockStyle.Fill);
+                Assert.AreEqual(((WebBrowser)markdownPreviewHandlerControl.Controls[0]).IsWebBrowserContextMenuEnabled, false);
+                Assert.AreEqual(((WebBrowser)markdownPreviewHandlerControl.Controls[0]).ScriptErrorsSuppressed, true);
+                Assert.AreEqual(((WebBrowser)markdownPreviewHandlerControl.Controls[0]).ScrollBarsEnabled, true);
+                Assert.AreEqual(((WebBrowser)markdownPreviewHandlerControl.Controls[0]).AllowNavigation, false);
+            } 
         }
 
         [TestMethod]
         public void MarkdownPreviewHandlerControl__UpdateInfobarSettings_WhenDoPreviewIsCalled()
         {
             // Arrange 
-            MarkdownPreviewHandlerControl markdownPreviewHandlerControl = new MarkdownPreviewHandlerControl();
+            using (var markdownPreviewHandlerControl = new MarkdownPreviewHandlerControl())
+            {
+                // Act
+                markdownPreviewHandlerControl.DoPreview<string>("HelperFiles/MarkdownWithExternalImage.txt");
 
-            // Act
-            markdownPreviewHandlerControl.DoPreview<string>("HelperFiles/MarkdownWithExternalImage.txt");
-
-            // Assert
-            Assert.IsInstanceOfType(markdownPreviewHandlerControl.Controls[1], typeof(RichTextBox));
-            Assert.IsNotNull(((RichTextBox)markdownPreviewHandlerControl.Controls[1]).Text);
-            Assert.AreEqual(((RichTextBox)markdownPreviewHandlerControl.Controls[1]).Dock, DockStyle.Top);
-            Assert.AreEqual(((RichTextBox)markdownPreviewHandlerControl.Controls[1]).BorderStyle, BorderStyle.None);
-            Assert.AreEqual(((RichTextBox)markdownPreviewHandlerControl.Controls[1]).BackColor, Color.LightYellow);
-            Assert.AreEqual(((RichTextBox)markdownPreviewHandlerControl.Controls[1]).Multiline, true);
+                // Assert
+                Assert.IsInstanceOfType(markdownPreviewHandlerControl.Controls[1], typeof(RichTextBox));
+                Assert.IsNotNull(((RichTextBox)markdownPreviewHandlerControl.Controls[1]).Text);
+                Assert.AreEqual(((RichTextBox)markdownPreviewHandlerControl.Controls[1]).Dock, DockStyle.Top);
+                Assert.AreEqual(((RichTextBox)markdownPreviewHandlerControl.Controls[1]).BorderStyle, BorderStyle.None);
+                Assert.AreEqual(((RichTextBox)markdownPreviewHandlerControl.Controls[1]).BackColor, Color.LightYellow);
+                Assert.AreEqual(((RichTextBox)markdownPreviewHandlerControl.Controls[1]).Multiline, true);
+            }
         }
     }
 }