ArchUnitNET

Visit our documentation at https://archunitnet.readthedocs.io/en/latest/.

ArchUnitNET is a free, simple library for checking the architecture of C# code. It is the C# fork of https://www.archunit.org/ for Java. ArchUnitNET can check dependencies between classes, members, interfaces, and more. This is done by analyzing C# bytecode and importing all classes into our C# code structure. The main focus of ArchUnitNET is to automatically test architecture and coding rules.

An Example

To use ArchUnitNET, install the ArchUnitNET package from NuGet:

PS> Install-Package TngTech.ArchUnitNET

If you want to use xUnit, NUnit or MSTestV2 for your unit tests, you should instead install the corresponding ArchUnit extension:

PS> Install-Package TngTech.ArchUnitNET.xUnit
PS> Install-Package TngTech.ArchUnitNET.NUnit
PS> Install-Package TngTech.ArchUnitNET.MSTestV2

Create a Test

Then you will want to create a class to start testing. We used xUnit with the ArchUnit extension here, but it works similarly with NUnit or other Unit Test Frameworks.

using ArchUnitNET.Domain;
using ArchUnitNET.Loader;
using ArchUnitNET.Fluent;
using Xunit;

//add a using directive to ArchUnitNET.Fluent.ArchRuleDefinition to easily define ArchRules
using static ArchUnitNET.Fluent.ArchRuleDefinition;


namespace ExampleTest
{
    public class ExampleArchUnitTest
    {
        // TIP: load your architecture once at the start to maximize performance of your tests
        private static readonly Architecture Architecture = new ArchLoader().LoadAssemblies(
            System.Reflection.Assembly.Load("ExampleClassAssemblyName"),
            System.Reflection.Assembly.Load("ForbiddenClassAssemblyName")
        ).Build();
        // replace <ExampleClass> and <ForbiddenClass> with classes from the assemblies you want to test

        //declare variables you'll use throughout your tests up here
        //use As() to give them a custom description
        private readonly IObjectProvider<IType> ExampleLayer =
            Types().That().ResideInAssembly("ExampleAssembly").As("Example Layer");

        private readonly IObjectProvider<Class> ExampleClasses =
            Classes().That().ImplementInterface("IExampleInterface").As("Example Classes");

        private readonly IObjectProvider<IType> ForbiddenLayer =
            Types().That().ResideInNamespace("ForbiddenNamespace").As("Forbidden Layer");

        private readonly IObjectProvider<Interface> ForbiddenInterfaces =
            Interfaces().That().HaveFullNameContaining("forbidden").As("Forbidden Interfaces");


        //write some tests
        [Fact]
        public void TypesShouldBeInCorrectLayer()
        {
            //you can use the fluent API to write your own rules
            IArchRule exampleClassesShouldBeInExampleLayer =
                Classes().That().Are(ExampleClasses).Should().Be(ExampleLayer);
            IArchRule forbiddenInterfacesShouldBeInForbiddenLayer =
                Interfaces().That().Are(ForbiddenInterfaces).Should().Be(ForbiddenLayer);

            //check if your architecture fulfils your rules
            exampleClassesShouldBeInExampleLayer.Check(Architecture);
            forbiddenInterfacesShouldBeInForbiddenLayer.Check(Architecture);

            //you can also combine your rules
            IArchRule combinedArchRule =
                exampleClassesShouldBeInExampleLayer.And(forbiddenInterfacesShouldBeInForbiddenLayer);
            combinedArchRule.Check(Architecture);
        }

        [Fact]
        public void ExampleLayerShouldNotAccessForbiddenLayer()
        {
            //you can give your rules a custom reason, which is displayed when it fails
            //(together with the types that failed the rule)
            IArchRule exampleLayerShouldNotAccessForbiddenLayer = Types().That().Are(ExampleLayer).Should()
                .NotDependOnAny(ForbiddenLayer).Because("it's forbidden");
            exampleLayerShouldNotAccessForbiddenLayer.Check(Architecture);
        }

        [Fact]
        public void ForbiddenClassesShouldHaveCorrectName()
        {
            Classes().That().AreAssignableTo(ForbiddenInterfaces).Should().HaveNameContaining("forbidden")
                .Check(Architecture);
        }

        [Fact]
        public void ExampleClassesShouldNotCallForbiddenMethods()
        {
            Classes().That().Are(ExampleClasses).Should().NotCallAny(
                    MethodMembers().That().AreDeclaredIn(ForbiddenLayer).Or().HaveNameContaining("forbidden"))
                .Check(Architecture);
        }
    }
}

Further Info and Help

Check out test examples for the current release at ArchUnitNET Examples.

License

ArchUnitNET is published under the Apache License 2.0. For more information concerning the license, see Apache License 2.0.