class DefaultComponentTypeRegistryTest extends Specification {

    def registry = new DefaultComponentTypeRegistry()

    def "fails getting registration for unregistered component"() {
        when:
        registry.getComponentRegistration(MyComponentType)

        then:
        def e = thrown IllegalArgumentException
        e.message == "Not a registered component type: ${MyComponentType.name}."
    }

import org.gradle.api.component.Component;

public interface ComponentTypeRegistry {
    ComponentTypeRegistration maybeRegisterComponentType(Class<? extends Component> componentType);

    ComponentTypeRegistration getComponentRegistration(Class<? extends Component> componentType);

            componentRegistrations.put(componentType, registration);
        }
        return registration;
    }

    @Override
    public ComponentTypeRegistration getComponentRegistration(Class<? extends Component> componentType) {
        ComponentTypeRegistration registration = componentRegistrations.get(componentType);
        if (registration == null) {

    }

    private ComponentTypeRegistry createTestComponentTypeRegistry() {
        return Stub(ComponentTypeRegistry) {
            getComponentRegistration(_) >> { Class componentType ->
                if (componentType == TestComponent) {
                    return createStubComponentRegistration()
                } else {

            }
        }
    }

    private <T extends Artifact> ArtifactType convertType(Class<T> requestedType) {
        return componentTypeRegistry.getComponentRegistration(componentType).getArtifactType(requestedType);
    }