How to mock Hibernate Query.list() using Mockito

Question

This is my class which need to be tested:

@Repository
@Transactional
public class ProductDAOImpl implements ProductDAO {

private static final Logger logger = Logger.getLogger(ProductDAOImpl.class);

@Autowired
private SessionFactory hibernateSessionFactory;


@Override
public ProductDTO getProduct(String isbn) throws ProductException {
    ProductDTO productDTO = new ProductDTO();
    Product product = getProductFromDb(isbn);
    BeanUtils.copyProperties(product, productDTO);
    return productDTO;
}

private Product getProductFromDb(String isbn) throws ProductException{
    Session session = this.hibernateSessionFactory.getCurrentSession();


    String hql = "FROM com.esp.dao.entity.Product P WHERE P.isbn13 = :isbn13";
    Query query = session.createQuery(hql);
    query.setParameter("isbn13",isbn);


    List<Product> productList = query.list();  // Want to mock this call
    if(productList.size() ==1)      
        return productList.get(0);
    else if(productList.size() >1)
        // throw new ProductException("Cannot return product. Multiple products found.", HttpServletResponse.SC_NOT_FOUND);
        throw new ProductException("Cannot return product. Multiple products found.");
    else if(productList.size() == 0){
        throw new ProductException("Cannot return product. No products found.");
    }
    return null;

}

I want to mock the query.list() method. This is what I have tried so far but getting exception: Type 'SessionFactory' is an interface and it cannot be spied on.

@RunWith(MockitoJUnitRunner.class)
public class TestProductDaoImpl {

@Spy
private SessionFactory hibernateSessionFactory;
@InjectMocks
private ProductDAOImpl productDAOImpl;

@Test
public void testGetProduct() throws ProductException {

    Session session = this.hibernateSessionFactory.getCurrentSession();

    String hql = "";
    Query query = session.createQuery(hql);
    Query spy = Mockito.spy(query);
    List<Product> productList = getProductList();
    doReturn(productList).when(spy).list();

    productDAOImpl.getProduct("abc");


}

I can mock the getProductFromDb(). But in that case there is no need to write a test case for that as the maximum part of the class is getting mocked.

Answer 1

In my opinion there are two approach:

First: Create mock on SessionFactory like this

@Mock
private SessionFactory hibernateSessionFactory;

@Before
public void beforeTest(){
    MockitoAnnotations.initMocks(this);
}

@Test
public void testGetProduct() throws ProductException {
     //then mock all you need from hibernateSessionFactory
     Session session = Mockito.mock(Session.class);
     Query query = Mockito.mock(Query.class);

     Mockito.when(hibernateSessionFactory.getCurrentSession()).thenReturn(session);
     Mockito.when(session.createQuery("FROM com.esp.dao.entity.Product P WHERE P.isbn13 = :isbn13")).thenReturn(query);

     List<Product> productList = new ArrayList<>(1);
     Mockito.when(query.list()).thenReturn(productList);

Second: You should create instance of SessionFactory

private SessionFactory hibernateSessionFactory;

@Before
public void beforeTest(){
    hibernateSessionFactory = Mockito.spy(new ConstructorForSessionFactory ());
}