Extensions¶

Convenience methods for common Roslyn operations.

See also: Queries | Projections | Emit

Overview¶

Extension methods organized by the type they extend. These wrap common Roslyn operations in fluent, null-safe APIs.

Category	Description
Symbol Extensions	ISymbol, INamedTypeSymbol, IMethodSymbol
Type Extensions	ITypeSymbol — collections, async, classification, equality, and more
Compilation Extensions	Compilation and namespace queries
Attribute Extensions	AttributeData extraction
String Extensions	Case conversion utilities
Domain Extensions	Entity Framework, LanguageExt, JSON utilities

Usage Examples¶

Find Async Methods Returning Entity Types¶

var asyncMethods = typeSymbol.QueryMethods()
    .ThatArePublic()
    .ThatAreAsync()
    .Where(m => m.ReturnType.IsGenericTaskType())
    .GetAll();

Check If Type Is Repository¶

bool isRepo = typeSymbol.IsInterfaceType() &&
              typeSymbol.Name.EndsWith("Repository") &&
              ((INamedTypeSymbol)typeSymbol).ImplementsInterface("IRepository");

Extract Attribute Configuration¶

var config = symbol.GetAttributesByName("Configure")
    .FirstOrDefault()
    ?.Query()
    .WithArgs(attr => new Config
    {
        Name = attr.ConstructorArg<string>(0).OrDefault("Default"),
        Enabled = attr.NamedArg<bool>("Enabled").OrDefault(true),
        Priority = attr.NamedArg<int>("Priority").OrDefault(0)
    })
    .OrDefault(Config.Default);

Check Type Hierarchy¶

if (typeSymbol.InheritsFrom("ControllerBase", "Microsoft.AspNetCore.Mvc"))
{
    var actions = typeSymbol.QueryMethods()
        .ThatArePublic()
        .ThatAreInstance()
        .WithoutAttribute<NonActionAttribute>()
        .GetAll();
}

Analyze Async Method Signatures¶

var method = typeSymbol.QueryMethods()
    .WithName("ProcessAsync")
    .FirstOrDefault();

if (method.IsValid(out var valid))
{
    var asyncKind = valid.Value.GetAsyncKind();
    var innerType = valid.Value.GetAsyncReturnType();

    if (valid.Value.IsAsyncVoid())
    {
        // Report diagnostic: async void is problematic
    }
}

Filter by Generated Code¶

var userDefinedTypes = TypeQuery.From(compilation)
    .ThatAreClasses()
    .Where(t => t.IsNotGeneratedCode())
    .GetAll();