Escape keywords in object initializer completion (#26740)

src/EditorFeatures/CSharpTest/Completion/CompletionProviders/ObjectInitializerCompletionProviderTests.cs

@@ -820,6 +820,36 @@ static void Main(string[] args)
             await VerifyItemExistsAsync(markup, "Value");
         }
 
+        [WorkItem(26560, "https://github.com/dotnet/roslyn/issues/26560")]
+        [Fact, Trait(Traits.Feature, Traits.Features.Completion)]
+        public async Task ObjectInitializerEscapeKeywords()
+        {
+            var markup = @"
+class c
+{
+    public int @new { get; set; }
+
+    public int @this { get; set; }
+
+    public int now { get; set; }
+}
+
+class d
+{
+    static void Main(string[] args)
+    {
+        var t = new c() { $$ };
+    }
+}";
+
+            await VerifyItemExistsAsync(markup, "@new");
+            await VerifyItemExistsAsync(markup, "@this");
+            await VerifyItemExistsAsync(markup, "now");
+
+            await VerifyItemIsAbsentAsync(markup, "new");
+            await VerifyItemIsAbsentAsync(markup, "this");
+        }
+
         private async Task VerifyExclusiveAsync(string markup, bool exclusive)
         {
             using (var workspace = TestWorkspace.CreateCSharp(markup))

src/EditorFeatures/VisualBasicTest/Completion/CompletionProviders/ObjectInitializerCompletionProviderTests.vb

@@ -435,6 +435,32 @@ End Program"
             Await VerifySendEnterThroughToEditorAsync(code, "bar", expected:=False)
         End Function
 
+        <WorkItem(26560, "https://github.com/dotnet/roslyn/issues/26560")>
+        <Fact, Trait(Traits.Feature, Traits.Features.Completion)>
+        Public Async Function TestKeywordsEscaped() As Task
+            Dim text = <a>Class C
+    Public Property [Wend] As Integer
+
+    Public Property [New] As Integer
+
+    Public Property A As Integer
+End Class
+
+
+Class Program
+    Sub Main()
+        Dim c As New C With { .$$ }
+    End Sub
+End Class</a>.Value
+
+            Await VerifyItemExistsAsync(text, "[Wend]")
+            Await VerifyItemExistsAsync(text, "[New]")
+            Await VerifyItemExistsAsync(text, "A")
+
+            Await VerifyItemIsAbsentAsync(text, "Wend")
+            Await VerifyItemIsAbsentAsync(text, "New")
+        End Function
+
         Friend Overrides Function CreateCompletionProvider() As CompletionProvider
             Return New ObjectInitializerCompletionProvider()
         End Function

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

@@ -178,5 +178,10 @@ protected override bool IsInitializable(ISymbol member, INamedTypeSymbol contain
 
             return base.IsInitializable(member, containingType);
         }
+
+        protected override string EscapeIdentifier(ISymbol symbol)
+        {
+            return symbol.Name.EscapeIdentifier();
+        }
     }
 }

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

@@ -15,6 +15,7 @@ internal abstract class AbstractObjectInitializerCompletionProvider : CommonComp
     {
         protected abstract Tuple<ITypeSymbol, Location> GetInitializedType(Document document, SemanticModel semanticModel, int position, CancellationToken cancellationToken);
         protected abstract HashSet<string> GetInitializedMembers(SyntaxTree tree, int position, CancellationToken cancellationToken);
+        protected abstract string EscapeIdentifier(ISymbol symbol);
 
         public override async Task ProvideCompletionsAsync(CompletionContext context)
         {
@@ -63,7 +64,7 @@ public override async Task ProvideCompletionsAsync(CompletionContext context)
             foreach (var uninitializedMember in uninitializedMembers)
             {
                 context.AddItem(SymbolCompletionItem.CreateWithSymbolId(
-                    displayText: uninitializedMember.Name,
+                    displayText: EscapeIdentifier(uninitializedMember),
                     insertionText: null,
                     symbols: ImmutableArray.Create(uninitializedMember),
                     contextPosition: initializerLocation.SourceSpan.Start,

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

@@ -93,6 +93,10 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Completion.Providers
                 member.IsAccessibleWithin(containingType)
         End Function
 
+        Protected Overrides Function EscapeIdentifier(symbol As ISymbol) As String
+            Return symbol.Name.EscapeIdentifier()
+        End Function
+
         Private Function IsValidProperty(member As ISymbol) As Boolean
             Dim [property] = TryCast(member, IPropertySymbol)
             If [property] IsNot Nothing Then