adam bien's blog

Unit Testing EJB 3.1 ...When 0.8 Seconds Are Too Long [SOURCE CODE INCLUDED] 📎

EJB 3 are just POJOs, so there is no need to unit-test them inside the EJB container. You could just instantiate them in the unit test. Sometimes it is needed to change a behavior of a session bean, to cause an exception or test the boundary in another:


@Stateless
public class ServiceFacade {
    @EJB
    Service service;

    public boolean isOne(){
        int nr = service.getNumber();
        return (nr == 1);
    }
}

I would like to test, whether the ServiceFacade returns "false" in case the number is not 1.
The problem:


@Stateless
public class Service {

    public int getNumber(){
        return 1;
    }
}

...its hardcoded.... Mockito is just perfect for testing such cases.


import com.abien.business.nointerface.control.Service;
import org.junit.Test;
import static org.junit.Assert.*;
import static org.mockito.Mockito.*;

public class ServiceFacadeTest {

    @Test
    public void twoIsFalse(){
        Service service = mock(Service.class);
        when(service.getNumber()).thenReturn(2);
        ServiceFacade facade = new ServiceFacade();
        facade.service = service;
        assertFalse(facade.isOne());
    }
}

You can easily change the return value of every (non-final) class for test purposes. The whole project, with mockito libraries, was pushed into http://kenai.com/projects/javaee-patterns (tested with Netbeans 6.7rc3 and Glassfish v3 Preview).

The whole test is executed in 0.2 seconds on my machine. Four times faster than 0.8 :-). Btw. Glassfish v3 (with EJB 3.1 container) starts in about 5-10 seconds - the whole application is deployed in about 2 seconds...

[In the Real World Patterns - Rethinking Best Practices book several unit-testing strategies are discussed - but not mockito. It will change in the Iteration Two]