NestedTypesTests.cs

using ArchUnitNET.Domain;
using ArchUnitNET.Loader;
using ArchUnitNET.xUnit;
using Xunit;
using static ArchUnitNET.Fluent.ArchRuleDefinition;

namespace ArchUnitNETTests.Loader
{
    public class NestedTypesTests
    {
        private static readonly Architecture Architecture = new ArchLoader()
            .LoadAssemblies(System.Reflection.Assembly.Load("ArchUnitNETTests"))
            .Build();

        [Fact]
        public void FindAllNestedTypes()
        {
            Types()
                .That()
                .Are(typeof(Layer1Class.Layer2Class))
                .Should()
                .Exist()
                .Check(Architecture);
            Types()
                .That()
                .Are(typeof(Layer1Class.Layer2Class.Layer3Class1))
                .Should()
                .Exist()
                .Check(Architecture);
            Types()
                .That()
                .Are(typeof(Layer1Class.Layer2Class.Layer3Class1.Layer4Class1))
                .Should()
                .Exist()
                .Check(Architecture);
            Types()
                .That()
                .Are(typeof(Layer1Class.Layer2Class.Layer3Class2))
                .Should()
                .Exist()
                .Check(Architecture);
            Types()
                .That()
                .Are(typeof(Layer1Class.Layer2Class.Layer3Class2.Layer4Class2))
                .Should()
                .Exist()
                .Check(Architecture);
        }
    }

    public class Layer1Class
    {
        public class Layer2Class
        {
            public class Layer3Class1
            {
                public class Layer4Class1 { }
            }

            public class Layer3Class2
            {
                public class Layer4Class2 { }
            }
        }
    }
}