dotnet/roslyn - Issue 66173

Link to the PR

In my recent work on the dotnet/roslyn repository, I encountered an interesting issue related to the handling of the async modifier for methods without a body. The Roslyn repository is the home of the .NET Compiler Platform, which provides open-source C# and Visual Basic compilers with rich code analysis APIs.

The Issue

The problem was identified in issue #66173, titled "SyntaxGenerator: Consider filtering async modifier for methods without a body". The existing code was:

var hasBody = !modifiers.IsAbstract && (!modifiers.IsPartial || statements != null);

modifiers: AsModifierList(accessibility, modifiers, SyntaxKind.MethodDeclaration),

The question was whether we should drop the async modifier if hasBody is false.

The Solution

To solve this issue, I added a check to remove the async modifier if hasBody is false. Here's the code change I made:

var hasBody = !modifiers.IsAbstract && (!modifiers.IsPartial || statements != null);

if (!hasBody)
    modifiers -= DeclarationModifiers.Async;

return SyntaxFactory.MethodDeclaration(
    attributeLists: default,
    modifiers: AsModifierList(accessibility, modifiers, SyntaxKind.MethodDeclaration),

This change ensures that the async modifier is correctly handled, improving the accuracy of the code generation.