Support top level statements in event hookup (#58475)

dotnet · Dec 24, 2021 · 678b269 · 678b269
1 parent d589d90
commit 678b269
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Showing 2 changed files with 38 additions and 5 deletions.
diff --git a/src/EditorFeatures/CSharp/EventHookup/EventHookupCommandHandler_TabKeyCommand.cs b/src/EditorFeatures/CSharp/EventHookup/EventHookupCommandHandler_TabKeyCommand.cs
@@ -186,9 +186,10 @@ private static Document AddMethodNameAndAnnotationsToSolution(
             var root = document.GetSyntaxRootSynchronously(cancellationToken);
             var plusEqualsToken = root.FindTokenOnLeftOfPosition(position);
             var eventHookupExpression = plusEqualsToken.GetAncestor<AssignmentExpressionSyntax>();
+            var typeDecl = eventHookupExpression.GetAncestor<TypeDeclarationSyntax>();
 
             var textToInsert = eventHandlerMethodName + ";";
-            if (!eventHookupExpression.IsInStaticContext())
+            if (!eventHookupExpression.IsInStaticContext() && typeDecl is not null)
             {
                 // This will be simplified later if it's not needed.
                 textToInsert = "this." + textToInsert;
@@ -222,24 +223,30 @@ private static SyntaxNode AddGeneratedHandlerMethodToSolution(
             var root = document.Root;
             var eventHookupExpression = root.GetAnnotatedNodesAndTokens(plusEqualsTokenAnnotation).Single().AsToken().GetAncestor<AssignmentExpressionSyntax>();
 
-            var generatedMethodSymbol = GetMethodSymbol(document, eventHandlerMethodName, eventHookupExpression, cancellationToken);
+            var typeDecl = eventHookupExpression.GetAncestor<TypeDeclarationSyntax>();
+            var methodKind = typeDecl is null
+                ? MethodKind.LocalFunction
+                : MethodKind.Ordinary;
+
+            var generatedMethodSymbol = GetMethodSymbol(document, eventHandlerMethodName, eventHookupExpression, methodKind, cancellationToken);
 
             if (generatedMethodSymbol == null)
             {
                 return null;
             }
 
-            var typeDecl = eventHookupExpression.GetAncestor<TypeDeclarationSyntax>();
+            var container = (SyntaxNode)typeDecl ?? eventHookupExpression.GetAncestor<CompilationUnitSyntax>();
 
-            var typeDeclWithMethodAdded = CodeGenerator.AddMethodDeclaration(typeDecl, generatedMethodSymbol, document.Project.Solution.Workspace, new CodeGenerationOptions(afterThisLocation: eventHookupExpression.GetLocation()));
+            var newContainer = CodeGenerator.AddMethodDeclaration(container, generatedMethodSymbol, document.Project.Solution.Workspace, new CodeGenerationOptions(afterThisLocation: eventHookupExpression.GetLocation()));
 
-            return root.ReplaceNode(typeDecl, typeDeclWithMethodAdded);
+            return root.ReplaceNode(container, newContainer);
         }
 
         private static IMethodSymbol GetMethodSymbol(
             SemanticDocument semanticDocument,
             string eventHandlerMethodName,
             AssignmentExpressionSyntax eventHookupExpression,
+            MethodKind methodKind,
             CancellationToken cancellationToken)
         {
             var semanticModel = semanticDocument.SemanticModel;
@@ -271,6 +278,7 @@ private static IMethodSymbol GetMethodSymbol(
                 name: eventHandlerMethodName,
                 typeParameters: default,
                 parameters: delegateInvokeMethod.Parameters,
+                methodKind: methodKind,
                 statements: ImmutableArray.Create(
                     CodeGenerationHelpers.GenerateThrowStatement(syntaxFactory, semanticDocument, "System.NotImplementedException")));
         }

diff --git a/src/EditorFeatures/CSharpTest/EventHookup/EventHookupCommandHandlerTests.cs b/src/EditorFeatures/CSharpTest/EventHookup/EventHookupCommandHandlerTests.cs
@@ -1024,6 +1024,31 @@ private void C_MyEvent()
             testState.AssertCodeIs(expectedCode);
         }
 
+        [WpfFact, Trait(Traits.Feature, Traits.Features.EventHookup)]
+        [WorkItem(58474, "https://github.com/dotnet/roslyn/issues/58474")]
+        public async Task EventHookupInTopLevelCode()
+        {
+            var markup = @"
+
+System.AppDomain.CurrentDomain.UnhandledException +$$
+
+";
+            using var testState = EventHookupTestState.CreateTestState(markup);
+            testState.SendTypeChar('=');
+            testState.SendTab();
+            await testState.WaitForAsynchronousOperationsAsync();
+
+            var expectedCode = @"
+
+System.AppDomain.CurrentDomain.UnhandledException += CurrentDomain_UnhandledException;
+
+void CurrentDomain_UnhandledException(object sender, System.UnhandledExceptionEventArgs e)
+{
+    throw new System.NotImplementedException();
+}";
+            testState.AssertCodeIs(expectedCode);
+        }
+
         private static OptionsCollection QualifyMethodAccessWithNotification(NotificationOption2 notification)
             => new OptionsCollection(LanguageNames.CSharp) { { CodeStyleOptions2.QualifyMethodAccess, true, notification } };
     }