Merge pull request #5494 from DustinCampbell/issue-5486

Fix issue when pressing ENTER in XML doc comments with a selection

src/EditorFeatures/CSharpTest/DocumentationComments/DocumentationCommentTests.cs

@@ -1264,6 +1264,52 @@ void M()
             VerifyPressingEnter(code, expected, useTabs: true);
         }
 
+        [WorkItem(5486, "https://github.com/dotnet/roslyn/issues/5486")]
+        [Fact, Trait(Traits.Feature, Traits.Features.DocumentationComments)]
+        public void PressingEnter_Selection1()
+        {
+            var code =
+@"/// <summary>
+/// Hello [|World|]$$!
+/// </summary>
+class C
+{
+}";
+            var expected =
+@"/// <summary>
+/// Hello 
+/// $$!
+/// </summary>
+class C
+{
+}";
+
+            VerifyPressingEnter(code, expected);
+        }
+
+        [WorkItem(5486, "https://github.com/dotnet/roslyn/issues/5486")]
+        [Fact, Trait(Traits.Feature, Traits.Features.DocumentationComments)]
+        public void PressingEnter_Selection2()
+        {
+            var code =
+@"/// <summary>
+/// Hello $$[|World|]!
+/// </summary>
+class C
+{
+}";
+            var expected =
+@"/// <summary>
+/// Hello 
+/// $$!
+/// </summary>
+class C
+{
+}";
+
+            VerifyPressingEnter(code, expected);
+        }
+
         [Fact, Trait(Traits.Feature, Traits.Features.DocumentationComments)]
         public void Command_Class()
         {

src/EditorFeatures/Core/Implementation/DocumentationComments/AbstractDocumentationCommentCommandHandler.cs

@@ -3,6 +3,7 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
+using System.Linq;
 using System.Threading;
 using Microsoft.CodeAnalysis.Editor.Commands;
 using Microsoft.CodeAnalysis.Editor.Host;
@@ -480,14 +481,34 @@ public void ExecuteCommand(ReturnKeyCommandArgs args, Action nextHandler)
             // Check to see if the current line starts with exterior trivia. If so, we'll take over.
             // If not, let the nextHandler run.
 
-            var caretPosition = args.TextView.GetCaretPoint(args.SubjectBuffer) ?? -1;
-            if (caretPosition < 0)
+            int originalPosition;
+
+            // The original position should be a position that is consistent with the syntax tree, even
+            // after Enter is pressed. Thus, we use the start of the first selection if there is one.
+            // Otherwise, getting the tokens to the right or the left might return unexpected results.
+
+            if (args.TextView.Selection.SelectedSpans.Count > 0)
+            {
+                var selectedSpan = args.TextView.Selection
+                    .GetSnapshotSpansOnBuffer(args.SubjectBuffer)
+                    .FirstOrNullable();
+
+                originalPosition = selectedSpan != null
+                    ? args.TextView.BufferGraph.MapUpOrDownToBuffer(selectedSpan.Value.Start, args.SubjectBuffer) ?? -1
+                    : (args.TextView.GetCaretPoint(args.SubjectBuffer) ?? -1);
+            }
+            else
+            {
+                originalPosition = args.TextView.GetCaretPoint(args.SubjectBuffer) ?? -1;
+            }
+
+            if (originalPosition < 0)
             {
                 nextHandler();
                 return;
             }
 
-            if (!CurrentLineStartsWithExteriorTrivia(args.SubjectBuffer, caretPosition))
+            if (!CurrentLineStartsWithExteriorTrivia(args.SubjectBuffer, originalPosition))
             {
                 nextHandler();
                 return;
@@ -509,7 +530,7 @@ public void ExecuteCommand(ReturnKeyCommandArgs args, Action nextHandler)
                 var editorOperations = _editorOperationsFactoryService.GetEditorOperations(args.TextView);
                 editorOperations.InsertNewLine();
 
-                CompleteComment(args.SubjectBuffer, args.TextView, caretPosition, InsertOnEnterTyped, CancellationToken.None);
+                CompleteComment(args.SubjectBuffer, args.TextView, originalPosition, InsertOnEnterTyped, CancellationToken.None);
 
                 // Since we're wrapping the ENTER key undo transaction, we always complete
                 // the transaction -- even if we didn't generate anything.

src/EditorFeatures/Test/DocumentationComments/AbstractDocumentationCommentTests.cs

@@ -118,7 +118,23 @@ private void Verify(string initialMarkup, string expectedMarkup, bool useTabs, A
             using (var workspace = CreateTestWorkspace(initialMarkup))
             {
                 var testDocument = workspace.Documents.Single();
+
+                Assert.True(testDocument.CursorPosition.HasValue, "No caret position set!");
+                var startCaretPosition = testDocument.CursorPosition.Value;
+
                 var view = testDocument.GetTextView();
+
+                if (testDocument.SelectedSpans.Any())
+                {
+                    var selectedSpan = testDocument.SelectedSpans[0];
+
+                    var isReversed = selectedSpan.Start == startCaretPosition
+                        ? true
+                        : false;
+
+                    view.Selection.Select(new SnapshotSpan(view.TextSnapshot, selectedSpan.Start, selectedSpan.Length), isReversed);
+                }
+
                 view.Caret.MoveTo(new SnapshotPoint(view.TextSnapshot, testDocument.CursorPosition.Value));
 
                 if (useTabs)
@@ -139,9 +155,9 @@ private void Verify(string initialMarkup, string expectedMarkup, bool useTabs, A
 
                 Assert.Equal(expectedCode, view.TextSnapshot.GetText());
 
-                var caretPosition = view.Caret.Position.BufferPosition.Position;
-                Assert.True(expectedPosition == caretPosition,
-                    string.Format("Caret positioned incorrectly. Should have been {0}, but was {1}.", expectedPosition, caretPosition));
+                var endCaretPosition = view.Caret.Position.BufferPosition.Position;
+                Assert.True(expectedPosition == endCaretPosition,
+                    string.Format("Caret positioned incorrectly. Should have been {0}, but was {1}.", expectedPosition, endCaretPosition));
             }
         }
     }

src/EditorFeatures/VisualBasicTest/DocumentationComments/DocumentationCommentTests.vb

@@ -736,6 +736,48 @@ End Class
             VerifyPressingEnter(code, expected, useTabs:=True)
         End Sub
 
+        <WorkItem(5486, "https://github.com/dotnet/roslyn/issues/5486")>
+        <Fact, Trait(Traits.Feature, Traits.Features.DocumentationComments)>
+        Public Sub PressingEnter_Selection1()
+            Const code = "
+''' <summary>
+''' Hello [|World|]$$!
+''' </summary>
+Class C
+End Class
+"
+            Const expected = "
+''' <summary>
+''' Hello 
+''' $$!
+''' </summary>
+Class C
+End Class
+"
+            VerifyPressingEnter(code, expected)
+        End Sub
+
+        <WorkItem(5486, "https://github.com/dotnet/roslyn/issues/5486")>
+        <Fact, Trait(Traits.Feature, Traits.Features.DocumentationComments)>
+        Public Sub PressingEnter_Selection2()
+            Const code = "
+''' <summary>
+''' Hello $$[|World|]!
+''' </summary>
+Class C
+End Class
+"
+            Const expected = "
+''' <summary>
+''' Hello 
+''' $$!
+''' </summary>
+Class C
+End Class
+"
+            VerifyPressingEnter(code, expected)
+        End Sub
+
         <Fact, Trait(Traits.Feature, Traits.Features.DocumentationComments)>
         Public Sub Command_Class()
             Const code = "