Restructure code.

src/EditorFeatures/Core/EditorFeatures.csproj

@@ -634,6 +634,7 @@
     <Compile Include="Shared\Tagging\EventSources\TaggerEventSources.EditorFormatMapChangedEventSource.cs" />
     <Compile Include="Shared\Tagging\EventSources\TaggerEventSources.ViewSpanChangedEventSource.cs" />
     <Compile Include="Shared\Utilities\SynchronizationContextTaskScheduler.cs" />
+    <Compile Include="Implementation\Suggestions\SuggestedActionWithPreview.cs" />
     <Compile Include="Tagging\AbstractAsynchronousTaggerProvider.Tagger.cs" />
     <Compile Include="Tagging\AbstractAsynchronousTaggerProvider.TagSource.cs" />
     <Compile Include="Tagging\AbstractAsynchronousTaggerProvider.TagSource_ReferenceCounting.cs" />

src/EditorFeatures/Core/Implementation/Suggestions/CodeFixSuggestedAction.cs

@@ -4,27 +4,23 @@
 using System.Collections.Immutable;
 using System.Globalization;
 using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Microsoft.CodeAnalysis.CodeActions;
 using Microsoft.CodeAnalysis.CodeFixes;
 using Microsoft.CodeAnalysis.Diagnostics;
 using Microsoft.CodeAnalysis.Editor.Host;
-using Microsoft.CodeAnalysis.Extensions;
 using Microsoft.CodeAnalysis.Shared.TestHooks;
 using Microsoft.VisualStudio.Language.Intellisense;
 using Microsoft.VisualStudio.Text;
-using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis.Editor.Implementation.Suggestions
 {
     /// <summary>
     /// Represents light bulb menu item for code fixes.
     /// </summary>
-    internal sealed class CodeFixSuggestedAction : SuggestedAction, ISuggestedActionWithFlavors, ITelemetryDiagnosticID<string>
+    internal sealed class CodeFixSuggestedAction : SuggestedActionWithPreview, ISuggestedActionWithFlavors, ITelemetryDiagnosticID<string>
     {
         private readonly CodeFix _fix;
-        public SuggestedActionSet FixAllSuggestedActionSet { get; }
+        private readonly SuggestedActionSet _fixAllSuggestedActionSet;
 
         private ImmutableArray<SuggestedActionSet> _actionSets;
 
@@ -41,126 +37,10 @@ internal sealed class CodeFixSuggestedAction : SuggestedAction, ISuggestedAction
             : base(workspace, subjectBuffer, editHandler, waitIndicator, action, provider, operationListener)
         {
             _fix = fix;
-            FixAllSuggestedActionSet = fixAllSuggestedActionSet;
+            _fixAllSuggestedActionSet = fixAllSuggestedActionSet;
         }
 
-        public override bool HasActionSets
-        {
-            get
-            {
-                // HasActionSets is called synchronously on the UI thread. In order to avoid blocking the UI thread,
-                // we need to provide a 'quick' answer here as opposed to the 'right' answer. Providing the 'right'
-                // answer is expensive (because we will need to call CodeAction.GetPreviewOperationsAsync() (to
-                // compute whether or not we should display the flavored action for 'Preview Changes') which in turn
-                // will involve computing the changed solution for the ApplyChangesOperation for the fix / refactoring
-                // So we always return 'true' here (so that platform will call GetActionSetsAsync() below). Platform
-                // guarantees that nothing bad will happen if we return 'true' here and later return 'null' / empty
-                // collection from within GetPreviewAsync().
-
-                return true;
-            }
-        }
-
-        public async override Task<IEnumerable<SuggestedActionSet>> GetActionSetsAsync(CancellationToken cancellationToken)
-        {
-            cancellationToken.ThrowIfCancellationRequested();
-
-            // Light bulb will always invoke this property on the UI thread.
-            AssertIsForeground();
-
-            if (_actionSets.IsDefault)
-            {
-                var extensionManager = this.Workspace.Services.GetService<IExtensionManager>();
-
-                _actionSets = await extensionManager.PerformFunctionAsync(Provider, async () =>
-                {
-                    var builder = ArrayBuilder<SuggestedActionSet>.GetInstance();
-
-                    // We use ConfigureAwait(true) to stay on the UI thread.
-                    var previewChangesSuggestedActionSet = await GetPreviewChangesSuggestedActionSetAsync(cancellationToken).ConfigureAwait(true);
-                    if (previewChangesSuggestedActionSet != null)
-                    {
-                        builder.Add(previewChangesSuggestedActionSet);
-                    }
-
-                    cancellationToken.ThrowIfCancellationRequested();
-
-                    var fixAllSuggestedActionSet = this.FixAllSuggestedActionSet;
-                    if (fixAllSuggestedActionSet != null)
-                    {
-                        builder.Add(fixAllSuggestedActionSet);
-                    }
-
-                    return builder.ToImmutableAndFree();
-                    // We use ConfigureAwait(true) to stay on the UI thread.
-                }, defaultValue: ImmutableArray<SuggestedActionSet>.Empty).ConfigureAwait(true);
-            }
-
-            Contract.ThrowIfTrue(_actionSets.IsDefault);
-            return _actionSets;
-        }
-
-        private async Task<SuggestedActionSet> GetPreviewChangesSuggestedActionSetAsync(CancellationToken cancellationToken)
-        {
-            var previewResult = await GetPreviewResultAsync(cancellationToken).ConfigureAwait(true);
-            if (previewResult == null)
-            {
-                return null;
-            }
-
-            var changeSummary = previewResult.ChangeSummary;
-            if (changeSummary == null)
-            {
-                return null;
-            }
-
-            var previewAction = new PreviewChangesCodeAction(Workspace, CodeAction, changeSummary);
-            var previewSuggestedAction = new PreviewChangesSuggestedAction(
-                Workspace, SubjectBuffer, EditHandler, WaitIndicator, previewAction, Provider, OperationListener);
-            return new SuggestedActionSet(ImmutableArray.Create(previewSuggestedAction));
-        }
-
-        /// <summary>
-        /// If the provided fix all context is non-null and the context's code action Id matches the given code action's Id then,
-        /// returns the set of fix all occurrences actions associated with the code action.
-        /// </summary>
-        internal static SuggestedActionSet GetFixAllSuggestedActionSet(
-            CodeAction action,
-            int actionCount,
-            FixAllState fixAllState,
-            IEnumerable<FixAllScope> supportedScopes,
-            Diagnostic firstDiagnostic,
-            Workspace workspace,
-            ITextBuffer subjectBuffer,
-            ICodeActionEditHandlerService editHandler,
-            IWaitIndicator waitIndicator,
-            IAsynchronousOperationListener operationListener)
-        {
-            if (fixAllState == null)
-            {
-                return null;
-            }
-
-            if (actionCount > 1 && action.EquivalenceKey == null)
-            {
-                return null;
-            }
-
-            var fixAllSuggestedActions = ArrayBuilder<FixAllSuggestedAction>.GetInstance();
-            foreach (var scope in supportedScopes)
-            {
-                var fixAllStateForScope = fixAllState.WithScopeAndEquivalenceKey(scope, action.EquivalenceKey);
-                var fixAllAction = new FixAllCodeAction(fixAllStateForScope, showPreviewChangesDialog: true);
-                var fixAllSuggestedAction = new FixAllSuggestedAction(
-                    workspace, subjectBuffer, editHandler, waitIndicator, fixAllAction,
-                    fixAllStateForScope.FixAllProvider, firstDiagnostic, operationListener);
-                fixAllSuggestedActions.Add(fixAllSuggestedAction);
-            }
-
-            return new SuggestedActionSet(
-                fixAllSuggestedActions.ToImmutableAndFree(),
-                title: EditorFeaturesResources.Fix_all_occurrences_in);
-        }
+        protected override SuggestedActionSet GetAdditionalActionSet() => _fixAllSuggestedActionSet;
 
         public string GetDiagnosticID()
         {

src/EditorFeatures/Core/Implementation/Suggestions/CodeRefactoringSuggestedAction.cs

@@ -11,7 +11,7 @@ namespace Microsoft.CodeAnalysis.Editor.Implementation.Suggestions
     /// <summary>
     /// Represents light bulb menu item for code refactorings.
     /// </summary>
-    internal sealed class CodeRefactoringSuggestedAction : SuggestedAction
+    internal sealed class CodeRefactoringSuggestedAction : SuggestedActionWithPreview
     {
         public CodeRefactoringSuggestedAction(
             Workspace workspace,
@@ -25,4 +25,4 @@ internal sealed class CodeRefactoringSuggestedAction : SuggestedAction
         {
         }
     }
-}
+}
\ No newline at end of file

src/EditorFeatures/Core/Implementation/Suggestions/SuggestedAction.cs

@@ -386,5 +386,25 @@ public override int GetHashCode()
         }
 
         #endregion
+
+        protected async Task<SuggestedActionSet> GetPreviewChangesSuggestedActionSetAsync(CancellationToken cancellationToken)
+        {
+            var previewResult = await GetPreviewResultAsync(cancellationToken).ConfigureAwait(true);
+            if (previewResult == null)
+            {
+                return null;
+            }
+
+            var changeSummary = previewResult.ChangeSummary;
+            if (changeSummary == null)
+            {
+                return null;
+            }
+
+            var previewAction = new PreviewChangesCodeAction(Workspace, CodeAction, changeSummary);
+            var previewSuggestedAction = new PreviewChangesSuggestedAction(
+                Workspace, SubjectBuffer, EditHandler, WaitIndicator, previewAction, Provider, OperationListener);
+            return new SuggestedActionSet(ImmutableArray.Create(previewSuggestedAction));
+        }
     }
 }

src/EditorFeatures/Core/Implementation/Suggestions/SuggestedActionWithChildActions.cs

+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
+using Microsoft.CodeAnalysis.CodeActions;
+using Microsoft.CodeAnalysis.Editor.Host;
+using Microsoft.CodeAnalysis.Shared.TestHooks;
+using Microsoft.VisualStudio.Language.Intellisense;
+using Microsoft.VisualStudio.Text;
+using Roslyn.Utilities;
+
+namespace Microsoft.CodeAnalysis.Editor.Implementation.Suggestions
+{
+    internal class SuggestedActionWithChildActions : SuggestedAction
+    {
+        public SuggestedActionWithChildActions(
+            Workspace workspace,
+            ITextBuffer subjectBuffer,
+            ICodeActionEditHandlerService editHandler,
+            IWaitIndicator waitIndicator,
+            CodeAction codeAction,
+            object provider,
+            IAsynchronousOperationListener operationListener,
+            SuggestedActionSet childActions)
+            : base(workspace, subjectBuffer, editHandler, waitIndicator,
+                  codeAction, provider, operationListener,
+                  SpecializedCollections.SingletonEnumerable(childActions))
+        {
+        }
+    }
+}
\ No newline at end of file

src/EditorFeatures/Core/Implementation/Suggestions/SuggestedActionWithPreview.cs

+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.CodeActions;
+using Microsoft.CodeAnalysis.Editor.Host;
+using Microsoft.CodeAnalysis.Extensions;
+using Microsoft.CodeAnalysis.Shared.TestHooks;
+using Microsoft.VisualStudio.Language.Intellisense;
+using Microsoft.VisualStudio.Text;
+using Roslyn.Utilities;
+
+namespace Microsoft.CodeAnalysis.Editor.Implementation.Suggestions
+{
+    internal class SuggestedActionWithPreview : SuggestedAction
+    {
+        private ImmutableArray<SuggestedActionSet> _actionSets;
+
+        public SuggestedActionWithPreview(
+            Workspace workspace, ITextBuffer subjectBuffer, ICodeActionEditHandlerService editHandler, 
+            IWaitIndicator waitIndicator, CodeAction codeAction, object provider, 
+            IAsynchronousOperationListener operationListener) 
+            : base(workspace, subjectBuffer, editHandler, waitIndicator, codeAction,
+                  provider, operationListener, actionSets: null)
+        {
+        }
+
+        // HasActionSets is called synchronously on the UI thread. In order to avoid blocking the UI thread,
+        // we need to provide a 'quick' answer here as opposed to the 'right' answer. Providing the 'right'
+        // answer is expensive (because we will need to call CodeAction.GetPreviewOperationsAsync() (to
+        // compute whether or not we should display the flavored action for 'Preview Changes') which in turn
+        // will involve computing the changed solution for the ApplyChangesOperation for the fix / refactoring
+        // So we always return 'true' here (so that platform will call GetActionSetsAsync() below). Platform
+        // guarantees that nothing bad will happen if we return 'true' here and later return 'null' / empty
+        // collection from within GetPreviewAsync().
+        public override bool HasActionSets => true;
+
+        public async sealed override Task<IEnumerable<SuggestedActionSet>> GetActionSetsAsync(CancellationToken cancellationToken)
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+
+            // Light bulb will always invoke this property on the UI thread.
+            AssertIsForeground();
+
+            if (_actionSets.IsDefault)
+            {
+                var extensionManager = this.Workspace.Services.GetService<IExtensionManager>();
+
+                _actionSets = await extensionManager.PerformFunctionAsync(Provider, async () =>
+                {
+                    var builder = ArrayBuilder<SuggestedActionSet>.GetInstance();
+
+                    // We use ConfigureAwait(true) to stay on the UI thread.
+                    var previewChangesSuggestedActionSet = await GetPreviewChangesSuggestedActionSetAsync(cancellationToken).ConfigureAwait(true);
+                    if (previewChangesSuggestedActionSet != null)
+                    {
+                        builder.Add(previewChangesSuggestedActionSet);
+                    }
+
+                    var additionalSet = this.GetAdditionalActionSet();
+                    if (additionalSet != null)
+                    {
+                        builder.Add(additionalSet);
+                    }
+
+                    return builder.ToImmutableAndFree();
+                    // We use ConfigureAwait(true) to stay on the UI thread.
+                }, defaultValue: ImmutableArray<SuggestedActionSet>.Empty).ConfigureAwait(true);
+            }
+
+            Contract.ThrowIfTrue(_actionSets.IsDefault);
+            return _actionSets;
+        }
+
+        protected virtual SuggestedActionSet GetAdditionalActionSet() => null;
+    }
+}
\ No newline at end of file

src/EditorFeatures/Core/Implementation/Suggestions/SuggestedActionsSourceProvider.cs

@@ -349,7 +349,7 @@ private IEnumerable<SuggestedActionSet> OrganizeFixes(Workspace workspace, IEnum
                     var fixCount = fixes.Length;
 
                     Func<CodeAction, SuggestedActionSet> getFixAllSuggestedActionSet = 
-                        codeAction => CodeFixSuggestedAction.GetFixAllSuggestedActionSet(
+                        codeAction => GetFixAllSuggestedActionSet(
                             codeAction, fixCount, fixCollection.FixAllState, 
                             fixCollection.SupportedScopes, fixCollection.FirstDiagnostic, 
                             workspace, _subjectBuffer,  _owner._editHandler, 
@@ -434,6 +434,48 @@ private IEnumerable<SuggestedActionSet> OrganizeFixes(Workspace workspace, IEnum
                 map[groupKey].Add(suggestedAction);
             }
 
+            /// <summary>
+            /// If the provided fix all context is non-null and the context's code action Id matches the given code action's Id then,
+            /// returns the set of fix all occurrences actions associated with the code action.
+            /// </summary>
+            internal static SuggestedActionSet GetFixAllSuggestedActionSet(
+                CodeAction action,
+                int actionCount,
+                FixAllState fixAllState,
+                IEnumerable<FixAllScope> supportedScopes,
+                Diagnostic firstDiagnostic,
+                Workspace workspace,
+                ITextBuffer subjectBuffer,
+                ICodeActionEditHandlerService editHandler,
+                IWaitIndicator waitIndicator,
+                IAsynchronousOperationListener operationListener)
+            {
+                if (fixAllState == null)
+                {
+                    return null;
+                }
+
+                if (actionCount > 1 && action.EquivalenceKey == null)
+                {
+                    return null;
+                }
+
+                var fixAllSuggestedActions = ArrayBuilder<FixAllSuggestedAction>.GetInstance();
+                foreach (var scope in supportedScopes)
+                {
+                    var fixAllStateForScope = fixAllState.WithScopeAndEquivalenceKey(scope, action.EquivalenceKey);
+                    var fixAllAction = new FixAllCodeAction(fixAllStateForScope, showPreviewChangesDialog: true);
+                    var fixAllSuggestedAction = new FixAllSuggestedAction(
+                        workspace, subjectBuffer, editHandler, waitIndicator, fixAllAction,
+                        fixAllStateForScope.FixAllProvider, firstDiagnostic, operationListener);
+                    fixAllSuggestedActions.Add(fixAllSuggestedAction);
+                }
+
+                return new SuggestedActionSet(
+                    fixAllSuggestedActions.ToImmutableAndFree(),
+                    title: EditorFeaturesResources.Fix_all_occurrences_in);
+            }
+
             /// <summary>
             /// Return prioritized set of fix groups such that fix group for suppression always show up at the bottom of the list.
             /// </summary>

src/EditorFeatures/VisualBasicTest/Diagnostics/SimplifyTypeNames/SimplifyTypeNamesTests.vb

@@ -891,7 +891,8 @@ End Namespace",
 "Imports System.Collections.Generic
 Namespace N1
     Class Test
-        Private a As [|System.Collections.Generic.List(Of System.String()(,)(,,,))
|]
+        Private a As [|System.Collections.Generic.List(Of System.String()(,)(,,,))
+|]
     End Class
 End Namespace",
 "Imports System.Collections.Generic