Add failing unit tests for Edit.OpenLineAbove and Edit.OpenLineBelow in C# XML doc comments

src/EditorFeatures/CSharpTest/DocumentationComments/DocumentationCommentTests.cs

@@ -1338,6 +1338,126 @@ public Class1()
             VerifyTypingCharacter(code, expected, useTab: true);
         }
 
+        [WorkItem(2090, "https://github.com/dotnet/roslyn/issues/2090")]
+        [Fact, Trait(Traits.Feature, Traits.Features.DocumentationComments)]
+        public void TestOpenLineAbove1()
+        {
+            const string code =
+@"class C
+{
+	/// <summary>
+    /// stuff$$
+    /// </summary>
+	void M()
+	{
+	}
+}";
+
+            var expected =
+@"class C
+{
+	/// <summary>
+    /// $$
+    /// stuff
+    /// </summary>
+	void M()
+	{
+	}
+}";
+
+            VerifyOpenLineAbove(code, expected);
+        }
+
+        [WorkItem(2090, "https://github.com/dotnet/roslyn/issues/2090")]
+        [Fact, Trait(Traits.Feature, Traits.Features.DocumentationComments)]
+        public void TestOpenLineAbove2()
+        {
+            const string code =
+@"class C
+{
+	/// <summary>
+    /// $$stuff
+    /// </summary>
+	void M()
+	{
+	}
+}";
+
+            const string expected =
+@"class C
+{
+	/// <summary>
+    /// $$
+    /// stuff
+    /// </summary>
+	void M()
+	{
+	}
+}";
+
+            VerifyOpenLineAbove(code, expected);
+        }
+
+        [WorkItem(2090, "https://github.com/dotnet/roslyn/issues/2090")]
+        [Fact, Trait(Traits.Feature, Traits.Features.DocumentationComments)]
+        public void TestOpenLineBelow1()
+        {
+            const string code =
+@"class C
+{
+	/// <summary>
+    /// stuff$$
+    /// </summary>
+	void M()
+	{
+	}
+}";
+
+            const string expected =
+@"class C
+{
+	/// <summary>
+    /// stuff
+    /// $$
+    /// </summary>
+	void M()
+	{
+	}
+}";
+
+            VerifyOpenLineBelow(code, expected);
+        }
+
+        [WorkItem(2090, "https://github.com/dotnet/roslyn/issues/2090")]
+        [Fact, Trait(Traits.Feature, Traits.Features.DocumentationComments)]
+        public void TestOpenLineBelow2()
+        {
+            const string code =
+@"class C
+{
+	/// <summary>
+    /// $$stuff
+    /// </summary>
+	void M()
+	{
+	}
+}";
+
+            const string expected =
+@"class C
+{
+	/// <summary>
+    /// stuff
+    /// $$
+    /// </summary>
+	void M()
+	{
+	}
+}";
+
+            VerifyOpenLineBelow(code, expected);
+        }
+
         protected override char DocumentationCommentCharacter
         {
             get { return '/'; }

src/EditorFeatures/Test/DocumentationComments/AbstractDocumentationCommentTests.cs

@@ -64,6 +64,32 @@ protected void VerifyInsertCommentCommand(string initialMarkup, string expectedM
             });
         }
 
+        protected void VerifyOpenLineAbove(string initialMarkup, string expectedMarkup)
+        {
+            Verify(initialMarkup, expectedMarkup, (view, undoHistoryRegistry, editorOperationsFactoryService, completionService) =>
+            {
+                var commandHandler = CreateCommandHandler(TestWaitIndicator.Default, undoHistoryRegistry, editorOperationsFactoryService, completionService) as ICommandHandler<OpenLineAboveCommandArgs>;
+
+                var commandArgs = new OpenLineAboveCommandArgs(view, view.TextBuffer);
+                Action nextHandler = delegate { };
+
+                commandHandler.ExecuteCommand(commandArgs, nextHandler);
+            });
+        }
+
+        protected void VerifyOpenLineBelow(string initialMarkup, string expectedMarkup)
+        {
+            Verify(initialMarkup, expectedMarkup, (view, undoHistoryRegistry, editorOperationsFactoryService, completionService) =>
+            {
+                var commandHandler = CreateCommandHandler(TestWaitIndicator.Default, undoHistoryRegistry, editorOperationsFactoryService, completionService) as ICommandHandler<OpenLineBelowCommandArgs>;
+
+                var commandArgs = new OpenLineBelowCommandArgs(view, view.TextBuffer);
+                Action nextHandler = delegate { };
+
+                commandHandler.ExecuteCommand(commandArgs, nextHandler);
+            });
+        }
+
         private Action CreateInsertTextHandler(ITextView textView, string text)
         {
             return () =>