Remove trailing comma when converting to a tuple (#75987)

Fixes #75950
dotnet · Nov 20, 2024 · e0d0509 · e0d0509
2 parents 9bea39d + 273f2a7
commit e0d0509
Showing 2 changed files with 34 additions and 7 deletions.
diff --git a/...Portable/ConvertAnonymousType/CSharpConvertAnonymousTypeToTupleCodeRefactoringProvider.cs b/...Portable/ConvertAnonymousType/CSharpConvertAnonymousTypeToTupleCodeRefactoringProvider.cs
@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using System.Collections.Generic;
 using System.Composition;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
@@ -29,17 +30,19 @@ protected override int GetInitializerCount(AnonymousObjectCreationExpressionSynt
 
     protected override TupleExpressionSyntax ConvertToTuple(AnonymousObjectCreationExpressionSyntax anonCreation)
         => TupleExpression(
-                OpenParenToken.WithTriviaFrom(anonCreation.OpenBraceToken),
-                ConvertInitializers(anonCreation.Initializers),
-                CloseParenToken.WithTriviaFrom(anonCreation.CloseBraceToken))
-                        .WithPrependedLeadingTrivia(anonCreation.GetLeadingTrivia());
+            OpenParenToken.WithTriviaFrom(anonCreation.OpenBraceToken),
+            ConvertInitializers(anonCreation.Initializers),
+            CloseParenToken.WithTriviaFrom(anonCreation.CloseBraceToken))
+                .WithPrependedLeadingTrivia(anonCreation.GetLeadingTrivia());
 
     private static SeparatedSyntaxList<ArgumentSyntax> ConvertInitializers(SeparatedSyntaxList<AnonymousObjectMemberDeclaratorSyntax> initializers)
-        => SeparatedList(initializers.Select(ConvertInitializer), initializers.GetSeparators());
+        => SeparatedList(initializers.Select(ConvertInitializer), GetSeparators(initializers));
+
+    private static IEnumerable<SyntaxToken> GetSeparators(SeparatedSyntaxList<AnonymousObjectMemberDeclaratorSyntax> initializers)
+        => initializers.Count == 0 ? [] : initializers.GetSeparators().Take(initializers.Count - 1);
 
     private static ArgumentSyntax ConvertInitializer(AnonymousObjectMemberDeclaratorSyntax declarator)
-        => Argument(ConvertName(declarator.NameEquals), default, declarator.Expression)
-                        .WithTriviaFrom(declarator);
+        => Argument(ConvertName(declarator.NameEquals), refKindKeyword: default, declarator.Expression).WithTriviaFrom(declarator);
 
     private static NameColonSyntax? ConvertName(NameEqualsSyntax? nameEquals)
         => nameEquals == null

diff --git a/src/Features/CSharpTest/ConvertAnonymousType/ConvertAnonymousTypeToTupleTests.cs b/src/Features/CSharpTest/ConvertAnonymousType/ConvertAnonymousTypeToTupleTests.cs
@@ -501,4 +501,28 @@ static void Main(string[] args)
             }
             """);
     }
+
+    [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/75950")]
+    public async Task RemoveTrailingComma()
+    {
+        var text = """
+            class Test
+            {
+                void Method()
+                {
+                    var t1 = [||]new { a = 1, b = 2, };
+                }
+            }
+            """;
+        var expected = """
+            class Test
+            {
+                void Method()
+                {
+                    var t1 = (a: 1, b: 2);
+                }
+            }
+            """;
+        await TestInRegularAndScriptAsync(text, expected);
+    }
 }