Deepstaging.Roslyn.Testing 1.0.0-dev-20260205052640

Deepstaging.Roslyn.Testing

Test utilities for Roslyn analyzers, generators, and code fixes.

📚 Full Documentation

See also: RoslynTestBase | Reference Configuration | Roslyn Toolkit

Quick Start

All tests inherit from RoslynTestBase:

public class MyTests : RoslynTestBase
{
    [Test]
    public async Task TestSymbols()
    {
        var type = SymbolsFor("public class Foo { }").RequireNamedType("Foo");
        await Assert.That(type.Value.Name).IsEqualTo("Foo");
    }

    [Test]
    public async Task TestAnalyzer()
    {
        await AnalyzeWith<MyAnalyzer>(source)
            .ShouldReportDiagnostic("MY001");
    }

    [Test]
    public async Task TestGenerator()
    {
        await GenerateWith<MyGenerator>(source)
            .ShouldGenerate()
            .VerifySnapshot();
    }

    [Test]
    public async Task TestCodeFix()
    {
        await AnalyzeAndFixWith<MyAnalyzer, MyCodeFix>(source)
            .ForDiagnostic("MY001")
            .ShouldProduce(expectedSource);
    }
}

Reference Configuration

If tests need your own assemblies, configure once via ModuleInitializer:

[ModuleInitializer]
public static void Init() =>
    ReferenceConfiguration.AddReferencesFromTypes(typeof(MyAttribute));

Entry Points

Documentation

Test Contexts

Each entry point returns a test context with fluent assertions:

• SymbolTestContext — Query symbols from compiled source
• AnalyzerTestContext — Assert on analyzer diagnostics
• GeneratorTestContext — Assert on generator output
• CodeFixTestContext — Assert on code fix transformations
• TemplateTestContext — Assert on template rendering

Guides

• RoslynTestBase — Full API reference for the base class
• Reference Configuration — Configure assembly references for tests

Quick Examples

Symbol Testing

var ctx = SymbolsFor(source);

// Get types and members
var type = ctx.RequireNamedType("Customer");
var methods = ctx.Type("Customer").Methods().ThatArePublic().GetAll();

Analyzer Testing

await AnalyzeWith<MyAnalyzer>(source)
    .ShouldReportDiagnostic("MY001")
    .WithSeverity(DiagnosticSeverity.Error)
    .WithMessage("*must be partial*");

Generator Testing

await GenerateWith<MyGenerator>(source)
    .ShouldGenerate()
    .WithFileCount(2)
    .WithFileNamed("Customer.g.cs")
    .WithNoDiagnostics()
    .VerifySnapshot();

Code Fix Testing

await AnalyzeAndFixWith<MyAnalyzer, MyCodeFix>(source)
    .ForDiagnostic("MY001")
    .ShouldProduce(expectedSource);

Template Testing

await RenderTemplateFrom<MyGenerator>(source)
    .Render("MyTemplate.scriban-cs", ctx => new { Name = ctx.RequireNamedType("Foo").Value.Name })
    .ShouldRender()
    .VerifySnapshot();

License

RPL-1.5 (Reciprocal Public License) — Real reciprocity, no loopholes.

You can use this code, modify it, and share it freely. But when you deploy it — internally or externally, as a service or within your company — you share your improvements back under the same license.

Why? We believe if you benefit from this code, the community should benefit from your improvements. That's the deal we think is fair.

Personal research and experimentation? No obligations. Go learn, explore, and build.

See LICENSE for the full legal text.