Don't retain placeholder when starting a review.

Starting a review by replying to an existing comment was causing the submitted comment's text to be copied into the placeholder after submission. Add a unit test to check for this and fix it.

Author: grokys

src/GitHub.InlineReviews/SampleData/CommentViewModelDesigner.cs

@@ -23,6 +23,7 @@ public CommentViewModelDesigner()
         public string ErrorMessage { get; set; }
         public CommentEditState EditState { get; set; }
         public bool IsReadOnly { get; set; }
+        public bool IsSubmitting { get; set; }
         public ICommentThreadViewModel Thread { get; }
         public DateTimeOffset UpdatedAt => DateTime.Now.Subtract(TimeSpan.FromDays(3));
         public IAccount User { get; set; }

src/GitHub.InlineReviews/ViewModels/CommentViewModel.cs

@@ -20,6 +20,7 @@ public class CommentViewModel : ReactiveObject, ICommentViewModel
         string body;
         string errorMessage;
         bool isReadOnly;
+        bool isSubmitting;
         CommentEditState state;
         DateTimeOffset updatedAt;
         string undoBody;
@@ -127,6 +128,7 @@ async Task DoCommitEdit(object unused)
             try
             {
                 ErrorMessage = null;
+                IsSubmitting = true;
 
                 var model = await Thread.PostComment.ExecuteAsyncTask(Body);
                 Id = model.Id;
@@ -140,6 +142,10 @@ async Task DoCommitEdit(object unused)
                 ErrorMessage = message;
                 log.Error(e, "Error posting comment");
             }
+            finally
+            {
+                IsSubmitting = false;
+            }
         }
 
         /// <inheritdoc/>
@@ -176,6 +182,13 @@ public bool IsReadOnly
             set { this.RaiseAndSetIfChanged(ref isReadOnly, value); }
         }
 
+        /// <inheritdoc/>
+        public bool IsSubmitting
+        {
+            get { return isSubmitting; }
+            protected set { this.RaiseAndSetIfChanged(ref isSubmitting, value); }
+        }
+
         /// <inheritdoc/>
         public DateTimeOffset UpdatedAt
         {

src/GitHub.InlineReviews/ViewModels/ICommentViewModel.cs

@@ -48,6 +48,12 @@ public interface ICommentViewModel : IViewModel
         /// </summary>
         bool IsReadOnly { get; set; }
 
+        /// <summary>
+        /// Gets a value indicating whether the comment is currently in the process of being
+        /// submitted.
+        /// </summary>
+        bool IsSubmitting { get; }
+
         /// <summary>
         /// Gets the modified date of the comment.
         /// </summary>

src/GitHub.InlineReviews/ViewModels/InlineCommentPeekViewModel.cs

@@ -154,7 +154,7 @@ async void LinesChanged(IReadOnlyList<Tuple<int, DiffSide>> lines)
 
         async Task UpdateThread()
         {
-            var placeholderBody = await GetPlaceholderBodyToPreserve();
+            var placeholderBody = GetPlaceholderBodyToPreserve();
 
             Thread = null;
             threadSubscription?.Dispose();
@@ -208,14 +208,13 @@ async Task SessionChanged(IPullRequestSession pullRequestSession)
             }
         }
 
-        async Task<string> GetPlaceholderBodyToPreserve()
+        string GetPlaceholderBodyToPreserve()
         {
             var lastComment = Thread?.Comments.LastOrDefault();
 
             if (lastComment?.EditState == CommentEditState.Editing)
             {
-                var executing = await lastComment.CommitEdit.IsExecuting.FirstAsync();
-                if (!executing) return lastComment.Body;
+                if (!lastComment.IsSubmitting) return lastComment.Body;
             }
 
             return null;

src/GitHub.InlineReviews/ViewModels/PullRequestReviewCommentViewModel.cs

@@ -120,8 +120,17 @@ public static CommentViewModel CreatePlaceholder(
 
         async Task DoStartReview(object unused)
         {
-            await session.StartReview();
-            await CommitEdit.ExecuteAsync(null);
+            IsSubmitting = true;
+
+            try
+            {
+                await session.StartReview();
+                await CommitEdit.ExecuteAsync(null);
+            }
+            finally
+            {
+                IsSubmitting = false;
+            }
         }
     }
 }

test/GitHub.InlineReviews.UnitTests/ViewModels/InlineCommentPeekViewModelTests.cs

@@ -195,7 +195,7 @@ public async Task RetainsCommentBeingEditedWhenSessionRefreshed()
         }
 
         [Test]
-        public async Task DoesntRetainSubmittedCommentInPlaceholderAfterPost()
+        public async Task CommittingEditDoesntRetainSubmittedCommentInPlaceholderAfterPost()
         {
             var sessionManager = CreateSessionManager();
             var peekSession = CreatePeekSession();
@@ -231,6 +231,43 @@ public async Task DoesntRetainSubmittedCommentInPlaceholderAfterPost()
             Assert.That(string.Empty, Is.EqualTo(placeholder.Body));
         }
 
+        [Test]
+        public async Task StartingReviewDoesntRetainSubmittedCommentInPlaceholderAfterPost()
+        {
+            var sessionManager = CreateSessionManager();
+            var peekSession = CreatePeekSession();
+            var target = new InlineCommentPeekViewModel(
+                CreatePeekService(lineNumber: 10),
+                peekSession,
+                sessionManager,
+                Substitute.For<INextInlineCommentCommand>(),
+                Substitute.For<IPreviousInlineCommentCommand>());
+
+            await target.Initialize();
+
+            Assert.That(2, Is.EqualTo(target.Thread.Comments.Count));
+
+            sessionManager.CurrentSession.StartReview()
+                .ReturnsForAnyArgs(async x =>
+                {
+                    var file = await sessionManager.GetLiveFile(
+                        RelativePath,
+                        peekSession.TextView,
+                        peekSession.TextView.TextBuffer);
+                    RaiseLinesChanged(file, Tuple.Create(10, DiffSide.Right));
+                    return Substitute.For<IPullRequestReviewModel>();
+                });
+
+            var placeholder = (IPullRequestReviewCommentViewModel)target.Thread.Comments.Last();
+            placeholder.BeginEdit.Execute(null);
+            placeholder.Body = "Comment being edited";
+            placeholder.StartReview.Execute(null);
+
+            placeholder = (IPullRequestReviewCommentViewModel)target.Thread.Comments.Last();
+            Assert.That(CommentEditState.Placeholder, Is.EqualTo(placeholder.EditState));
+            Assert.That(string.Empty, Is.EqualTo(placeholder.Body));
+        }
+
         void AddCommentToExistingThread(IPullRequestSessionFile file)
         {
             var newThreads = file.InlineCommentThreads.ToList();