Hide text changes.

src/Features/Core/Portable/AddImport/CodeActions/AddImportCodeAction.cs

@@ -32,7 +32,7 @@ private abstract class AddImportCodeAction : CodeAction
             /// <summary>
             /// The changes to make to <see cref="OriginalDocument"/> to add the import.
             /// </summary>
-            protected readonly ImmutableArray<TextChange> TextChanges;
+            private readonly ImmutableArray<TextChange> _textChanges;
 
             protected AddImportCodeAction(
                 Document originalDocument,
@@ -41,16 +41,16 @@ private abstract class AddImportCodeAction : CodeAction
                 CodeActionPriority priority)
             {
                 OriginalDocument = originalDocument;
-                TextChanges = textChanges;
                 Title = title;
                 Tags = tags;
                 Priority = priority;
+                _textChanges = textChanges;
             }
 
             protected async Task<Document> GetUpdatedDocumentAsync(CancellationToken cancellationToken)
             {
                 var oldText = await OriginalDocument.GetTextAsync(cancellationToken).ConfigureAwait(false);
-                var newText = oldText.WithChanges(TextChanges);
+                var newText = oldText.WithChanges(_textChanges);
                 var newDocument = OriginalDocument.WithText(newText);
 
                 return newDocument;

src/Features/Core/Portable/AddImport/CodeActions/InstallPackageAndAddImportCodeAction.cs

@@ -73,8 +73,10 @@ private async Task<Solution> GetUpdatedSolutionAsync(CancellationToken cancellat
                 protected override async Task<IEnumerable<CodeActionOperation>> ComputeOperationsAsync(
                     CancellationToken cancellationToken)
                 {
+                    var updatedDocument = await GetUpdatedDocumentAsync(cancellationToken).ConfigureAwait(false);
+
                     var oldText = await OriginalDocument.GetTextAsync(cancellationToken).ConfigureAwait(false);
-                    var newText = oldText.WithChanges(TextChanges);
+                    var newText = await updatedDocument.GetTextAsync(cancellationToken).ConfigureAwait(false);
 
                     return ImmutableArray.Create<CodeActionOperation>(
                         new InstallPackageAndAddImportOperation(