Handle nested code actions

src/OmniSharp.Abstractions/Extensions/ReflectionExtensions.cs

@@ -34,11 +34,12 @@ public static Lazy<MethodInfo> LazyGetMethod(this Lazy<Type> lazyType, string me
 
             return new Lazy<MethodInfo>(() =>
             {
-                var methodInfo = lazyType.Value.GetMethod(methodName);
+                var type = lazyType.Value;
+                var methodInfo = type.GetMethod(methodName);
 
                 if (methodInfo == null)
                 {
-                    throw new InvalidOperationException($"Could not get type '{methodName}'");
+                    throw new InvalidOperationException($"Could not get method '{methodName}' on type '{type.FullName}'");
                 }
 
                 return methodInfo;
@@ -54,11 +55,12 @@ public static Lazy<MethodInfo> LazyGetMethod(this Lazy<Type> lazyType, string me
 
             return new Lazy<MethodInfo>(() =>
             {
-                var methodInfo = lazyType.Value.GetMethod(methodName, bindingFlags);
+                var type = lazyType.Value;
+                var methodInfo = type.GetMethod(methodName, bindingFlags);
 
                 if (methodInfo == null)
                 {
-                    throw new InvalidOperationException($"Could not get type '{methodName}'");
+                    throw new InvalidOperationException($"Could not get method '{methodName}' on type '{type.FullName}'");
                 }
 
                 return methodInfo;
@@ -72,11 +74,12 @@ public static MethodInfo GetMethod(this Lazy<Type> lazyType, string methodName)
                 throw new ArgumentNullException(nameof(lazyType));
             }
 
-            var methodInfo = lazyType.Value.GetMethod(methodName);
+            var type = lazyType.Value;
+            var methodInfo = type.GetMethod(methodName);
 
             if (methodInfo == null)
             {
-                throw new InvalidOperationException($"Could not get type '{methodName}'");
+                throw new InvalidOperationException($"Could not get method '{methodName}' on type '{type.FullName}'");
             }
 
             return methodInfo;
@@ -89,11 +92,12 @@ public static MethodInfo GetMethod(this Lazy<Type> lazyType, string methodName,
                 throw new ArgumentNullException(nameof(lazyType));
             }
 
-            var methodInfo = lazyType.Value.GetMethod(methodName, bindingFlags);
+            var type = lazyType.Value;
+            var methodInfo = type.GetMethod(methodName, bindingFlags);
 
             if (methodInfo == null)
             {
-                throw new InvalidOperationException($"Could not get type '{methodName}'");
+                throw new InvalidOperationException($"Could not get method '{methodName}' on type '{type.FullName}'");
             }
 
             return methodInfo;

src/OmniSharp.Roslyn.CSharp/Services/Refactoring/V2/AvailableCodeAction.cs

@@ -0,0 +1,42 @@
+using System;
+using System.Collections.Immutable;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.CodeActions;
+
+namespace OmniSharp.Roslyn.CSharp.Services.Refactoring.V2
+{
+    public class AvailableCodeAction
+    {
+        public CodeAction CodeAction { get; }
+        public CodeAction ParentCodeAction { get; }
+
+        public AvailableCodeAction(CodeAction codeAction, CodeAction parentCodeAction = null)
+        {
+            if (codeAction == null)
+            {
+                throw new ArgumentNullException(nameof(codeAction));
+            }
+
+            this.CodeAction = codeAction;
+            this.ParentCodeAction = parentCodeAction;
+        }
+
+        public string GetIdentifier()
+        {
+            return CodeAction.EquivalenceKey ?? GetTitle();
+        }
+
+        public string GetTitle()
+        {
+            return ParentCodeAction != null
+                ? $"{ParentCodeAction.Title} -> {CodeAction.Title}"
+                : CodeAction.Title;
+        }
+
+        public Task<ImmutableArray<CodeActionOperation>> GetOperationsAsync(CancellationToken cancellationToken)
+        {
+            return CodeAction.GetOperationsAsync(cancellationToken);
+        }
+    }
+}

src/OmniSharp.Roslyn.CSharp/Services/Refactoring/V2/BaseCodeActionService.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Linq;
+using System.Reflection;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis;
@@ -11,9 +12,10 @@
 using Microsoft.CodeAnalysis.Text;
 using Microsoft.Extensions.Logging;
 using OmniSharp.Models.V2;
+using OmniSharp.Roslyn.CSharp.Services.CodeActions;
 using OmniSharp.Services;
 
-namespace OmniSharp.Roslyn.CSharp.Services.CodeActions
+namespace OmniSharp.Roslyn.CSharp.Services.Refactoring.V2
 {
     public abstract class BaseCodeActionService<TRequest, TResponse> : RequestHandler<TRequest, TResponse>
     {
@@ -23,41 +25,63 @@ public abstract class BaseCodeActionService<TRequest, TResponse> : RequestHandle
 
         private readonly CodeActionHelper _helper;
 
+        private readonly MethodInfo _getNestedCodeActions;
+
         protected BaseCodeActionService(OmniSharpWorkspace workspace, CodeActionHelper helper, IEnumerable<ICodeActionProvider> providers, ILogger logger)
         {
             this.Workspace = workspace;
             this.Providers = providers;
             this.Logger = logger;
             this._helper = helper;
+
+            // Sadly, the CodeAction.NestedCodeActions property is still internal.
+            var nestedCodeActionsProperty = typeof(CodeAction).GetProperty("NestedCodeActions", BindingFlags.NonPublic | BindingFlags.Instance);
+            if (nestedCodeActionsProperty == null)
+            {
+                throw new InvalidOperationException("Could not find CodeAction.NestedCodeActions property.");
+            }
+
+            this._getNestedCodeActions = nestedCodeActionsProperty.GetGetMethod(nonPublic: true);
+            if (this._getNestedCodeActions == null)
+            {
+                throw new InvalidOperationException("Could not retrieve 'get' method for CodeAction.NestedCodeActions property.");
+            }
         }
 
         public abstract Task<TResponse> Handle(TRequest request);
 
-
-        protected async Task<IEnumerable<CodeAction>> GetActionsAsync(ICodeActionRequest request)
+        protected async Task<IEnumerable<AvailableCodeAction>> GetAvailableCodeActions(ICodeActionRequest request)
         {
-            var actions = new List<CodeAction>();
             var originalDocument = this.Workspace.GetDocument(request.FileName);
             if (originalDocument == null)
             {
-                return actions;
+                return Array.Empty<AvailableCodeAction>();
             }
 
-            var refactoringContext = await GetRefactoringContext(originalDocument, request, actions);
-            if (refactoringContext != null)
-            {
-                await CollectRefactoringActions(refactoringContext.Value);
-            }
+            var actions = new List<CodeAction>();
 
             var codeFixContext = await GetCodeFixContext(originalDocument, request, actions);
             if (codeFixContext != null)
             {
                 await CollectCodeFixActions(codeFixContext.Value);
             }
 
+            var refactoringContext = await GetRefactoringContext(originalDocument, request, actions);
+            if (refactoringContext != null)
+            {
+                await CollectRefactoringActions(refactoringContext.Value);
+            }
+
+            // TODO: Determine good way to order code actions.
             actions.Reverse();
 
-            return actions;
+            // Be sure to filter out any code actions that inherit from CodeActionWithOptions.
+            // This isn't a great solution and might need changing later, but every Roslyn code action
+            // derived from this type tries to display a dialog. For now, this is a reasonable solution.
+            var availableActions = ConvertToAvailableCodeAction(actions)
+                .Where(a => !a.CodeAction.GetType().GetTypeInfo().IsSubclassOf(typeof(CodeActionWithOptions)));
+
+            return availableActions;
         }
 
         private async Task<CodeRefactoringContext?> GetRefactoringContext(Document originalDocument, ICodeActionRequest request, List<CodeAction> actionsDestination)
@@ -124,7 +148,7 @@ private async Task CollectCodeFixActions(CodeFixContext context)
                     // TODO: This is a horrible hack! However, remove unnecessary usings only
                     // responds for diagnostics that are produced by its diagnostic analyzer.
                     // We need to provide a *real* diagnostic engine to address this.
-                    if (codeFix.ToString() != CodeActionHelper.RemoveUnnecessaryUsingsProviderName)
+                    if (codeFix.GetType().FullName != CodeActionHelper.RemoveUnnecessaryUsingsProviderName)
                     {
                         if (!diagnosticIds.Any(id => codeFix.FixableDiagnosticIds.Contains(id)))
                         {
@@ -166,5 +190,35 @@ private async Task CollectRefactoringActions(CodeRefactoringContext context)
                 }
             }
         }
+
+        private IEnumerable<AvailableCodeAction> ConvertToAvailableCodeAction(IEnumerable<CodeAction> actions)
+        {
+            var codeActions = new List<AvailableCodeAction>();
+
+            foreach (var action in actions)
+            {
+                var handledNestedActions = false;
+
+                // Roslyn supports "nested" code actions in order to allow submenus in the VS light bulb menu.
+                // For now, we'll just expand nested code actions in place.
+                var nestedActions = this._getNestedCodeActions.Invoke<ImmutableArray<CodeAction>>(action, null);
+                if (nestedActions.Length > 0)
+                {
+                    foreach (var nestedAction in nestedActions)
+                    {
+                        codeActions.Add(new AvailableCodeAction(nestedAction, action));
+                    }
+
+                    handledNestedActions = true;
+                }
+
+                if (!handledNestedActions)
+                {
+                    codeActions.Add(new AvailableCodeAction(action));
+                }
+            }
+
+            return codeActions;
+        }
     }
 }

src/OmniSharp.Roslyn.CSharp/Services/Refactoring/V2/GetCodeActionsService.cs

@@ -6,7 +6,6 @@
 using Microsoft.Extensions.Logging;
 using OmniSharp.Mef;
 using OmniSharp.Models.V2;
-using OmniSharp.Roslyn.CSharp.Extensions;
 using OmniSharp.Roslyn.CSharp.Services.CodeActions;
 using OmniSharp.Services;
 
@@ -27,12 +26,17 @@ public GetCodeActionsService(
 
         public override async Task<GetCodeActionsResponse> Handle(GetCodeActionsRequest request)
         {
-            var actions = await GetActionsAsync(request);
+            var availableActions = await GetAvailableCodeActions(request);
 
             return new GetCodeActionsResponse
             {
-                CodeActions = actions.Select(a => new OmniSharpCodeAction(a.GetIdentifier(), a.Title))
+                CodeActions = availableActions.Select(ConvertToOmniSharpCodeAction)
             };
         }
+
+        private static OmniSharpCodeAction ConvertToOmniSharpCodeAction(AvailableCodeAction availableAction)
+        {
+            return new OmniSharpCodeAction(availableAction.GetIdentifier(), availableAction.GetTitle());
+        }
     }
 }

src/OmniSharp.Roslyn.CSharp/Services/Refactoring/V2/RunCodeActionService.cs

@@ -9,7 +9,6 @@
 using Microsoft.Extensions.Logging;
 using OmniSharp.Mef;
 using OmniSharp.Models;
-using OmniSharp.Roslyn.CSharp.Extensions;
 using OmniSharp.Roslyn.CSharp.Services.CodeActions;
 using OmniSharp.Services;
 
@@ -33,16 +32,16 @@ public RunCodeActionService(
 
         public override async Task<RunCodeActionResponse> Handle(RunCodeActionRequest request)
         {
-            var actions = await GetActionsAsync(request);
-            var action = actions.FirstOrDefault(a => a.GetIdentifier().Equals(request.Identifier));
-            if (action == null)
+            var availableActions = await GetAvailableCodeActions(request);
+            var availableAction = availableActions.FirstOrDefault(a => a.GetIdentifier().Equals(request.Identifier));
+            if (availableAction == null)
             {
                 return new RunCodeActionResponse();
             }
 
-            Logger.LogInformation($"Applying code action: {action.Title}");
+            Logger.LogInformation($"Applying code action: {availableAction.GetTitle()}");
 
-            var operations = await action.GetOperationsAsync(CancellationToken.None);
+            var operations = await availableAction.GetOperationsAsync(CancellationToken.None);
 
             var solution = this.Workspace.CurrentSolution;
             var changes = new List<ModifiedFileResponse>();