Question

I have a backing bean called e.g. PeopleListBean. Purpose is simple: return a list of people from a repository.

public class PeopleListBean {

    @Autowired
    private PersonRepository personRepository;

    private List<Person> people;

    @PostConstruct
    private void initializeBean() {     
        this.people = loadPeople();
    }

    public List<User> getPeople() {
        return this.people;
    }

    private List<Person> loadPeople() {
        return personRepository.getPeople();
    }

}

I want to create a unit test for this bean, using Junit and Mockito.
Example test class below:

import static org.junit.Assert.assertTrue;
import static org.mockito.Mockito.reset;
import static org.mockito.Mockito.when;

import java.util.ArrayList;
import java.util.List;

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import com.example.PersonRepository;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = { "classpath:/test-application-context.xml" })
public class PeopleListBeanTest {

    @Autowired
    private PeopleListBean peopleListBean;
    @Autowired
    private PersonRepository mockPersonRepository;

    @Before
    public void init() {
        reset(mockPersonRepository);
    }

    @Test
    public void canListPeople() {
        List<Person> people = getDummyList();

        when(mockPersonRepository.getPeople().thenReturn(people);

        assertTrue(peopleListBean.getPeople().size() == people.size());
    }
}

My issue is, when/how to mock the repository since the loading takes place in the initializeBean method (@PostConstruct). So after the class is constructed, the “getPeople” method is called before I can actually mock the method resulting in an assertion mismatch.

I’d really appreciate some help/guidance!

Answer 1

Use JUnit’s @BeforeClass annotation

Your code would therefore look as follows:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = { "classpath:/test-application-context.xml" })
public class PeopleListBeanTest {

    @Autowired
    private PeopleListBean peopleListBean;
    @Autowired
    private PersonRepository mockPersonRepository;

    @BeforeClass
    public static void initialise() {

    }

    // .
    // .
    // .
}