cdi-unit-test.md

Dependency Injection in JUnit 5

CDI 2.0 comes with an api to start a cdi container outside of an ee container. You can leverage this api to support dependency injection in JUnit tests.

Setup

Start the container in a method annotated with @BeforeAll and stop it in a method annotated with @AfterAll.

In a method annotated with @BeforeEach, you may want to configure injection into your test instance like seen below.

class CdiTest {

    private static SeContainer cdiContainer;
    private InjectionTarget<CdiTest> injectionTarget;

    @Inject
    private MyTestableService serviceUnderTest;

    @BeforeAll
    static void startCdiContainer() {
        cdiContainer = SeContainerInitializer.newInstance().initialize();
    }

    @BeforeEach
    void inject() {
        BeanManager beanManager = cdiContainer.getBeanManager();
        AnnotatedType<CdiTest> annotatedType = beanManager.createAnnotatedType(CdiTest.class);
        CreationalContext<CdiTest> injectionTarget = beanManager.createInjectionTarget(annotatedType);
        creationalContext = beanManager.createCreationalContext(null);
        injectionTarget.inject(this, creationalContext);
        injectionTarget.postConstruct(this);
    }

    @AfterEach
    void destroy() {
        injectionTarget.preDestroy(this);
        injectionTarget.dispose(this);
    }

    @AfterAll
    static void closeCdiContainer() {
        cdiContainer.close();
    }

    @Test
    void testService() {
        ...
    }
}

In the example above, MyTestableService will be injected with all of its dependencies resolved and injected, too. If you want to mock some of the dependencies, see the README.

Setup using OpenWebBeans JUnit 5 extension

With the OpenWebBeans JUnit 5 extension you just have to annotate your test class with @Cdi.

@Cdi
class CdiTest {

    @Inject
    private MyTestableService serviceUnderTest;

    @Test
    void testService() {
        ...
    }
}