Neon.Roslyn.Xunit 4.0.5

Neon.Roslyn.Xunit

This package provides some utilities to test Roslyn analyzers, code fix providers, and source generators using FluentAssertions.

Install

dotnet add package Neon.Roslyn.Xunit

Testing an analyzer

Verify generated source code

var inputSource = @"
namespace MyNamespace
{
    public partial class MyClass
    {
        public void MyMethod()
        {
            Console.WriteLine(""Hello, World!"");
        }
    }
}";

var expectedSource = @"
namespace MyNamespace
{
    public partial class MyClass
    {
        public void MyGeneratedMethod()
        {
            Console.WriteLine(""Hello, Roslyn!"");
        }
    }
}";

var testCompilation = new TestCompilationBuilder()
    .AddSourceGenerator<MySourceGenerator>()
    .AddSource(source)
    .Build();

// verify that the expected source code was generated
testCompilation.Should().ContainSource(expectedSource);

// verify the number of generated source files
testCompilation.Sources.Should().HaveCount(1);

Verify diagnostics

var testCompilation = new TestCompilationBuilder()
    .AddSourceGenerator<MySourceGenerator>()
    .AddSource(mySource)
    .Build();

// verify the number of diagnostics
testCompilation.Diagnostics.Should().HaveCount(2);

// verify the specific diagnostics using the diagnostic code
testCompilation.Should().HaveDiagnostics(["D1001", "D1002"]);

// verify the specific diagnostics using the diagnostic descriptor
testCompilation.Should().HaveDiagnostic(
    diagnostic: Diagnostic.Create(
        descriptor:  MyDiagnosticDescriptor,
        location:    Location.None,
        messageArgs: ["foo", 123]));

Adding assemblies to the compilation

var testCompilation = new TestCompilationBuilder()
    .AddSourceGenerator<MySourceGenerator>()
    .AddAssembly(typeof(MyType).Assembly)
    .Build();

Adding MSBuild options to the compilation

var testCompilation = new TestCompilationBuilder()
    .AddSourceGenerator<MySourceGenerator>()
    .AddOption("build_property.TargetFramework", "net8.0")
    .Build();