ArchitectureTest.java

import com.tngtech.archunit.junit.AnalyzeClasses;
import com.tngtech.archunit.junit.ArchTest;
import com.tngtech.archunit.lang.ArchRule;

import static com.tngtech.archunit.library.Architectures.layeredArchitecture;

@AnalyzeClasses(packages = "br.com.helpdev.myapp")
class ArchitectureTest {

    @ArchTest
    static final ArchRule layer_dependencies_are_respected = layeredArchitecture()
        .consideringAllDependencies()
        .layer("Controller").definedBy("..controller..")
        .layer("Service").definedBy("..service..")
        .layer("Persistence").definedBy("..persistence..")

        .whereLayer("Controller").mayNotBeAccessedByAnyLayer()
        .whereLayer("Service").mayOnlyBeAccessedByLayers("Controller")
        .whereLayer("Persistence").mayOnlyBeAccessedByLayers("Service")
}

NameConventionsTest.java

@ArchTest
static ArchRule app_class_name_should_be_app =
        classes().that()
          .areAnnotatedWith(SpringBootApplication.class)
          .should().haveSimpleName("MainApplication");

@ArchTest
static ArchRule controllers_should_be_suffixed =
        classes().that()
          .resideInAPackage("..controller..")
          .or().areAnnotatedWith(RestController.class)
          .should().haveSimpleNameEndingWith("Controller")
          //Note that the allowEmptyShould(true) option allows tests to fail if the given project contains no controllers.
          .allowEmptyShould(true);