How can I inject CDI event with HK2 in JUnit Test?

I would like to test my Jakarta application (Payara) with simply JUnit Test (without arquillian, without MicroShed).

I use ServiceLocator from Hk2 to inject service and its work well for my JPA entity and Service.

private static ServiceLocator serviceLocator;

@BeforeAll
public static void setUpBeforeClass() {
    serviceLocator = ServiceLocatorUtilities.createAndPopulateServiceLocator();
    ServiceLocatorUtilities.addClasses(
            serviceLocator,
            EntityManagerHK2Factory.class,
            ProducerUtils.class,
            FishService.class,
            ShopRepository.class,
            Family.class, Fish.class, FishStockKey.class, Shop.class, Stock.class, WaterType.class);
}

@Test
public void it_should_sell_fish() {
    //GIVEN
    FishService fishService = serviceLocator.getService(FishService.class);
    String shopName = "Magic Fish";
    String fishName = "Scalaire";
    int quantity = 3;
    //WHEN
    float bill = fishService.sell(shopName, fishName, quantity);
    //THEN
    assertThat(bill, is(54f));
}

But I have some issues since I had include CDI event inside my FishService.

@Inject
private Event<StockEvent> stockEvent;

And then I fire an event.

When I launch the test serviceLocator does not manage to create the FishService and I get the following error:

A MultiException has 3 exceptions.  They are:
1. org.glassfish.hk2.api.UnsatisfiedDependencyException: There was no object available for injection at SystemInjecteeImpl(requiredType=Event<StockEvent>,parent=FishService,qualifiers={},position=-1,optional=false,self=false,unqualified=null,976949492)
2. java.lang.IllegalArgumentException: While attempting to resolve the dependencies of com.meynier.jakarta.service.FishService errors were found
3. java.lang.IllegalStateException: Unable to perform operation: resolve on com.meynier.jakarta.service.FishService

In this test class I don't want to test the event CDI feature.

How can I use Hk2 to inject the CDI event service ? (My code is host in this github account)

Solution

You can use Mockito to mock the Event and then bind the mock with an AbstractBinder and add that to the ServiceLocator. Here's a complete test

import javax.inject.Inject;

import org.glassfish.hk2.api.ServiceLocator;
import org.glassfish.hk2.api.TypeLiteral;
import org.glassfish.hk2.utilities.Binder;
import org.glassfish.hk2.utilities.ServiceLocatorUtilities;
import org.glassfish.hk2.utilities.binding.AbstractBinder;
import org.junit.BeforeClass;
import org.junit.Test;

import static org.assertj.core.api.Assertions.assertThat;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

public class Hk2CdiInjectTest {

    public interface Event<T> {
        T get();
    }

    public interface StockEvent {
        String getStock();
    }

    public static class Service {

        @Inject
        private Event<StockEvent> event;

        public String getStock() {
            return event.get().getStock();
        }
    }

    private static ServiceLocator locator;

    @BeforeClass
    public static void setUpBeforeClass() {
        locator = ServiceLocatorUtilities.createAndPopulateServiceLocator();
        ServiceLocatorUtilities.addClasses(locator, Service.class);

        final Event<StockEvent> event = (Event<StockEvent>) mock(Event.class);
        final StockEvent stockEvent = mock(StockEvent.class);
        when(stockEvent.getStock()).thenReturn("GOOGL UP!");
        when(event.get()).thenReturn(stockEvent);
        Binder eventBinder = new AbstractBinder() {
            @Override
            public void configure() {
                bind(event).to(new TypeLiteral<Event<StockEvent>>() {});
            }
        };
        ServiceLocatorUtilities.bind(locator, eventBinder);
    }

    @Test
    public void testIt() {
        Service service = locator.getService(Service.class);

        assertThat(service.getStock()).isEqualTo("GOOGL UP!");
    }
}