netarchtest-generator

Architecture Tests Generator (NetArchTest)

Turn architectural rules into automated tests so violations fail the build instead of slowly rotting the codebase — layering, dependencies, naming, and boundary rules tailored to the project.

Input — point it at your project

Works on a target: a solution/project or GitHub URL. Detect the structure to enforce: find <target> -name "*.csproj", and the style (Clean layers? Vertical Slice? modules?) via folder names and references.

Setup

dotnet add package NetArchTest.Rules

Rules (tailored to the detected architecture)

Clean Architecture dependency rule:

[Fact]
public void Domain_has_no_outward_dependencies()
{
    var r = Types.InAssembly(typeof(Order).Assembly)
        .Should().NotHaveDependencyOnAny("MyApp.Application", "MyApp.Infrastructure", "MyApp.Api")
        .GetResult();
    Assert.True(r.IsSuccessful, string.Join("\n", r.FailingTypeNames ?? new()));
}

Other common fitness functions:

// Handlers must be sealed
Types.InAssembly(asm).That().HaveNameEndingWith("Handler").Should().BeSealed();
// Controllers/endpoints don't reference DbContext directly
Types.InAssembly(asm).That().HaveNameEndingWith("Controller").ShouldNot().HaveDependencyOn("MyApp.Infrastructure.Data");
// Modules don't reference each other's internals (modular monolith)
Types.InAssembly(ordersAsm).ShouldNot().HaveDependencyOn("MyApp.Modules.Billing");
// Async methods end with "Async"
Types.InAssembly(asm).That().HaveNameMatching(".*").Should()...; // naming conventions

Principles

• Encode the rules you actually care about — every test should map to a real architectural decision.
• Architecture tests are fitness functions: cheap, fast, run in CI, fail loudly.
• Match the rules to the real structure (don't impose Clean rules on a Vertical Slice app).
• A handful of high-value rules beats dozens of pedantic ones.

How to use it & best prompts

"Add architecture tests to enforce my layers", "stop controllers from using DbContext", "enforce that handlers are sealed", "guardrail tests for my modular monolith". Pairs with clean-architecture-scaffolder, modular-monolith-generator, and the dotnet-architecture-reviewer agent.