Bypass the Preview Changes dialog for Fix All testing

src/Features/Core/Portable/CodeFixes/FixAllOccurrences/FixSomeCodeAction.cs

@@ -16,7 +16,7 @@ internal abstract class FixSomeCodeAction : CodeAction
         private static readonly HashSet<string> s_predefinedCodeFixProviderNames = GetPredefinedCodeFixProviderNames();
 
         internal readonly FixAllState FixAllState;
-        private readonly bool _showPreviewChangesDialog;
+        private bool _showPreviewChangesDialog;
 
         internal FixSomeCodeAction(
             FixAllState fixAllState, bool showPreviewChangesDialog)
@@ -84,5 +84,28 @@ private static HashSet<string> GetPredefinedCodeFixProviderNames()
 
             return names;
         }
+
+        internal TestAccessor GetTestAccessor()
+        {
+            return new TestAccessor(this);
+        }
+
+        internal readonly struct TestAccessor
+        {
+            private readonly FixSomeCodeAction _fixSomeCodeAction;
+
+            internal TestAccessor(FixSomeCodeAction fixSomeCodeAction)
+            {
+                _fixSomeCodeAction = fixSomeCodeAction;
+            }
+
+            /// <summary>
+            /// Gets a reference to <see cref="_showPreviewChangesDialog"/>, which can be read or written by test code.
+            /// </summary>
+            public ref bool ShowPreviewChangesDialog
+            {
+                get => ref _fixSomeCodeAction._showPreviewChangesDialog;
+            }
+        }
     }
 }

src/VisualStudio/IntegrationTest/IntegrationTests/CSharp/CSharpCodeActions.cs

@@ -215,12 +215,7 @@ class C
             VisualStudio.Editor.Verify.CodeAction(
                 "Use expression body for properties",
                 applyFix: true,
-                fixAllScope: FixAllScope.Project,
-                blockUntilComplete: false);
-
-            var expectedTitle = "Preview Changes - Fix all occurrences";
-            VisualStudio.PreviewChangesDialog.VerifyOpen(expectedTitle, Helper.HangMitigatingTimeout);
-            VisualStudio.PreviewChangesDialog.ClickApplyAndWaitForFeature(expectedTitle, FeatureAttribute.DiagnosticService);
+                fixAllScope: FixAllScope.Project);
 
             Assert.Equal(expectedText, VisualStudio.Editor.GetText());
 
@@ -243,11 +238,7 @@ class C
             VisualStudio.Editor.Verify.CodeAction(
                 "Use block body for properties",
                 applyFix: true,
-                fixAllScope: FixAllScope.Project,
-                blockUntilComplete: false);
-
-            VisualStudio.PreviewChangesDialog.VerifyOpen(expectedTitle, Helper.HangMitigatingTimeout);
-            VisualStudio.PreviewChangesDialog.ClickApplyAndWaitForFeature(expectedTitle, FeatureAttribute.DiagnosticService);
+                fixAllScope: FixAllScope.Project);
 
             expectedText = @"
 class C

src/VisualStudio/IntegrationTest/TestUtilities/InProcess/TextViewWindow_InProc.cs

@@ -15,6 +15,7 @@
 using Microsoft.VisualStudio.Text.Editor;
 using Microsoft.VisualStudio.Text.Operations;
 using Microsoft.VisualStudio.Text.Tagging;
+using Roslyn.Utilities;
 using OLECMDEXECOPT = Microsoft.VisualStudio.OLE.Interop.OLECMDEXECOPT;
 using ThreadHelper = Microsoft.VisualStudio.Shell.ThreadHelper;
 
@@ -319,7 +320,7 @@ private async Task<IEnumerable<ISuggestedAction>> GetLightBulbActionsAsync(ILigh
 
         public void ApplyLightBulbAction(string actionName, FixAllScope? fixAllScope, bool blockUntilComplete)
         {
-            var lightBulbAction = GetLightBulbApplicationAction(actionName, fixAllScope);
+            var lightBulbAction = GetLightBulbApplicationAction(actionName, fixAllScope, blockUntilComplete);
             var task = ThreadHelper.JoinableTaskFactory.RunAsync(async () =>
             {
                 await ThreadHelper.JoinableTaskFactory.SwitchToMainThreadAsync();
@@ -340,7 +341,7 @@ public void ApplyLightBulbAction(string actionName, FixAllScope? fixAllScope, bo
         private void BeginInvokeExecuteOnActiveView(Action<IWpfTextView> action)
             => BeginInvokeOnUIThread(GetExecuteOnActionViewCallback(action));
 
-        private Func<IWpfTextView, Task> GetLightBulbApplicationAction(string actionName, FixAllScope? fixAllScope)
+        private Func<IWpfTextView, Task> GetLightBulbApplicationAction(string actionName, FixAllScope? fixAllScope, bool willBlockUntilComplete)
         {
             return async view =>
             {
@@ -378,6 +379,17 @@ private void BeginInvokeExecuteOnActiveView(Action<IWpfTextView> action)
                         throw new InvalidOperationException($"Unable to find FixAll in {fixAllScope.ToString()} code fix for suggested action '{action.DisplayText}'.");
                     }
 
+                    if (willBlockUntilComplete
+                        && action is FixAllSuggestedAction fixAllSuggestedAction
+                        && fixAllSuggestedAction.CodeAction is FixSomeCodeAction fixSomeCodeAction)
+                    {
+                        // Ensure the preview changes dialog will not be shown. Since the operation 'willBlockUntilComplete',
+                        // the caller would not be able to interact with the preview changes dialog, and the tests would
+                        // either timeout or deadlock.
+                        fixSomeCodeAction.GetTestAccessor().ShowPreviewChangesDialog = false;
+
+                    }
+
                     if (string.IsNullOrEmpty(actionName))
                     {
                         return;