Fix 'await completion' adding async to the wrong member

src/EditorFeatures/Test2/IntelliSense/CSharpCompletionCommandHandlerTests_AwaitCompletion.vb

@@ -1091,5 +1091,80 @@ static class Program
                 Await state.AssertLineTextAroundCaret("        await c!.SomeTask!.ConfigureAwait(false)", ";")
             End Using
         End Function
+
+        <WpfFact, WorkItem("https://github.com/dotnet/roslyn/issues/67952")>
+        Public Async Function AwaitCompletion_AfterLocalFunction1() As Task
+            Using state = TestStateFactory.CreateCSharpTestState(
+                <Document><![CDATA[
+class C
+{
+    public void Test()
+    {
+        void Image_ImageOpened()
+        {
+        }
+
+        awai$$ Goo();
+    }
+}
+]]>
+                </Document>)
+                state.SendInvokeCompletionList()
+                Await state.AssertSelectedCompletionItem(displayText:="await", isHardSelected:=True)
+
+                state.SendTab()
+                Assert.Equal("
+class C
+{
+    public async void Test()
+    {
+        void Image_ImageOpened()
+        {
+        }
+
+        await Goo();
+    }
+}
+", state.GetDocumentText())
+            End Using
+        End Function
+
+        <WpfFact, WorkItem("https://github.com/dotnet/roslyn/issues/67952")>
+        Public Async Function AwaitCompletion_AfterLocalFunction2() As Task
+            Using state = TestStateFactory.CreateCSharpTestState(
+                <Document><![CDATA[
+class C
+{
+    public void Test()
+    {
+        void Image_ImageOpened()
+        {
+        }
+
+        $$ Goo();
+    }
+}
+]]>
+                </Document>)
+                state.SendInvokeCompletionList()
+                Await state.AssertCompletionItemsContain(displayText:="await", displayTextSuffix:="")
+
+                state.SendTypeChars("awai")
+                state.SendTab()
+                Assert.Equal("
+class C
+{
+    public async void Test()
+    {
+        void Image_ImageOpened()
+        {
+        }
+
+        await Goo();
+    }
+}
+", state.GetDocumentText())
+            End Using
+        End Function
     End Class
 End Namespace

src/Features/CSharp/Portable/Completion/CompletionProviders/AwaitCompletionProvider.cs

@@ -13,24 +13,20 @@
 using Microsoft.CodeAnalysis.CSharp.LanguageService;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.Host.Mef;
+using Microsoft.CodeAnalysis.Shared.Extensions;
 using Microsoft.CodeAnalysis.Shared.Extensions.ContextQuery;
 using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis.CSharp.Completion.Providers;
 
-[ExportCompletionProvider(nameof(AwaitCompletionProvider), LanguageNames.CSharp)]
+[ExportCompletionProvider(nameof(AwaitCompletionProvider), LanguageNames.CSharp), Shared]
 [ExtensionOrder(After = nameof(KeywordCompletionProvider))]
-[Shared]
-internal sealed class AwaitCompletionProvider : AbstractAwaitCompletionProvider
+[method: ImportingConstructor]
+[method: Obsolete(MefConstruction.ImportingConstructorMessage, error: true)]
+internal sealed class AwaitCompletionProvider() : AbstractAwaitCompletionProvider(CSharpSyntaxFacts.Instance)
 {
-    [ImportingConstructor]
-    [Obsolete(MefConstruction.ImportingConstructorMessage, error: true)]
-    public AwaitCompletionProvider()
-        : base(CSharpSyntaxFacts.Instance)
-    {
-    }
-
     internal override string Language => LanguageNames.CSharp;
+
     public override ImmutableHashSet<char> TriggerCharacters => CompletionUtilities.CommonTriggerCharactersWithArgumentList;
 
     protected override bool IsAwaitKeywordContext(SyntaxContext syntaxContext)
@@ -55,24 +51,35 @@ protected override int GetSpanStart(SyntaxNode declaration)
         };
     }
 
-    protected override SyntaxNode? GetAsyncSupportingDeclaration(SyntaxToken token)
+    protected override SyntaxNode? GetAsyncSupportingDeclaration(SyntaxToken leftToken, int position)
     {
         // In a case like
         //   someTask.$$
         //   await Test();
         // someTask.await Test() is parsed as a local function statement.
         // We skip this and look further up in the hierarchy.
-        var parent = token.Parent;
+        var parent = leftToken.Parent;
         if (parent == null)
             return null;
 
-        if (parent is QualifiedNameSyntax { Parent: LocalFunctionStatementSyntax localFunction } qualifiedName &&
-            localFunction.ReturnType == qualifiedName)
+        if (parent is NameSyntax { Parent: LocalFunctionStatementSyntax localFunction } name &&
+            localFunction.ReturnType == name)
         {
-            parent = localFunction;
+            parent = localFunction.GetRequiredParent();
         }
 
-        return parent.AncestorsAndSelf().FirstOrDefault(node => node.IsAsyncSupportingFunctionSyntax());
+        return parent.AncestorsAndSelf().FirstOrDefault(node =>
+        {
+            if (!node.IsAsyncSupportingFunctionSyntax())
+                return false;
+
+            // Ensure that if we were outside of the async-supporting-function that we don't return it as the thing to
+            // make async.  We want to make its parent async.
+            if (position > leftToken.FullSpan.End)
+                return node.Span.Contains(position);
+
+            return node.Span.IntersectsWith(position);
+        });
     }
 
     protected override SyntaxNode? GetExpressionToPlaceAwaitInFrontOf(SyntaxTree syntaxTree, int position, CancellationToken cancellationToken)

src/Features/Core/Portable/Completion/Providers/AbstractAwaitCompletionProvider.cs

@@ -24,7 +24,8 @@ namespace Microsoft.CodeAnalysis.Completion.Providers;
 /// </summary>
 internal abstract class AbstractAwaitCompletionProvider : LSPCompletionProvider
 {
-    private const string AwaitCompletionTargetTokenPosition = nameof(AwaitCompletionTargetTokenPosition);
+    private const string Position = nameof(Position);
+    private const string LeftTokenPosition = nameof(LeftTokenPosition);
     private const string AppendConfigureAwait = nameof(AppendConfigureAwait);
     private const string MakeContainerAsync = nameof(MakeContainerAsync);
 
@@ -59,7 +60,7 @@ protected AbstractAwaitCompletionProvider(ISyntaxFacts syntaxFacts)
     /// </summary>
     protected abstract int GetSpanStart(SyntaxNode declaration);
 
-    protected abstract SyntaxNode? GetAsyncSupportingDeclaration(SyntaxToken token);
+    protected abstract SyntaxNode? GetAsyncSupportingDeclaration(SyntaxToken leftToken, int position);
 
     protected abstract ITypeSymbol? GetTypeSymbolOfExpression(SemanticModel semanticModel, SyntaxNode potentialAwaitableExpression, CancellationToken cancellationToken);
     protected abstract SyntaxNode? GetExpressionToPlaceAwaitInFrontOf(SyntaxTree syntaxTree, int position, CancellationToken cancellationToken);
@@ -95,12 +96,13 @@ public sealed override async Task ProvideCompletionsAsync(CompletionContext cont
         if (!isAwaitKeywordContext && dotAwaitContext == DotAwaitContext.None)
             return;
 
-        var token = syntaxContext.TargetToken;
-        var declaration = GetAsyncSupportingDeclaration(token);
+        var leftToken = syntaxContext.LeftToken;
+        var declaration = GetAsyncSupportingDeclaration(leftToken, position);
 
         using var builder = TemporaryArray<KeyValuePair<string, string>>.Empty;
 
-        builder.Add(KeyValuePairUtil.Create(AwaitCompletionTargetTokenPosition, token.SpanStart.ToString()));
+        builder.Add(KeyValuePairUtil.Create(Position, position.ToString()));
+        builder.Add(KeyValuePairUtil.Create(LeftTokenPosition, leftToken.SpanStart.ToString()));
 
         var makeContainerAsync = declaration is not null && !SyntaxGenerator.GetGenerator(document).GetModifiers(declaration).IsAsync;
         if (makeContainerAsync)
@@ -178,8 +180,9 @@ public sealed override async Task<CompletionChange> GetChangeAsync(Document docu
         if (item.TryGetProperty(MakeContainerAsync, out var _))
         {
             var root = await syntaxTree.GetRootAsync(cancellationToken).ConfigureAwait(false);
-            var tokenPosition = int.Parse(item.GetProperty(AwaitCompletionTargetTokenPosition));
-            var declaration = GetAsyncSupportingDeclaration(root.FindToken(tokenPosition));
+            var position = int.Parse(item.GetProperty(Position));
+            var leftTokenPosition = int.Parse(item.GetProperty(LeftTokenPosition));
+            var declaration = GetAsyncSupportingDeclaration(root.FindToken(leftTokenPosition), position);
             if (declaration is null)
             {
                 // IsComplexTextEdit should only be true when GetAsyncSupportingDeclaration returns non-null.

src/Features/VisualBasic/Portable/Completion/CompletionProviders/AwaitCompletionProvider.vb

@@ -12,9 +12,8 @@ Imports Microsoft.CodeAnalysis.VisualBasic.LanguageService
 Imports Microsoft.CodeAnalysis.VisualBasic.Syntax
 
 Namespace Microsoft.CodeAnalysis.VisualBasic.Completion.Providers
-    <ExportCompletionProvider(NameOf(AwaitCompletionProvider), LanguageNames.VisualBasic)>
+    <ExportCompletionProvider(NameOf(AwaitCompletionProvider), LanguageNames.VisualBasic), [Shared]>
     <ExtensionOrder(After:=NameOf(KeywordCompletionProvider))>
-    <[Shared]>
     Friend NotInheritable Class AwaitCompletionProvider
         Inherits AbstractAwaitCompletionProvider
 
@@ -47,8 +46,8 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Completion.Providers
             Throw ExceptionUtilities.Unreachable
         End Function
 
-        Protected Overrides Function GetAsyncSupportingDeclaration(token As SyntaxToken) As SyntaxNode
-            Return token.GetAncestor(Function(node) node.IsAsyncSupportedFunctionSyntax())
+        Protected Overrides Function GetAsyncSupportingDeclaration(targetToken As SyntaxToken, position As Integer) As SyntaxNode
+            Return targetToken.GetAncestor(Function(node) node.IsAsyncSupportedFunctionSyntax())
         End Function
 
         Protected Overrides Function GetTypeSymbolOfExpression(semanticModel As SemanticModel, potentialAwaitableExpression As SyntaxNode, cancellationToken As CancellationToken) As ITypeSymbol