Test EntityManager with JUnit and Mockito

Question

I have tried to test the following class, but I have been unsuccessful.

    @PersistenceContext
    private EntityManager em;

    @Transactional
    public int sendToTableOne()
    {
        return em.createNativeQuery("INSERT INTO TABLE_ONE"
                        + " SELECT * FROM TABLE_TWO")
                .executeUpdate();
    }

How can I test this class?

I'm using JUnit Jupiter on Spring framework.

Answer 1

I don't know if it's a good solution, but I obtain 100% coverage.

@Mock
EntityManager entityManager;

@Mock
Query query;

@InjectMocks
ThSwapDaoImpl daoImpl;

@BeforeEach
void setUp() throws Exception {
}

@Test
void test() {
    
    when(entityManager.createNativeQuery(anyString())).thenReturn(query);
    when(query.executeUpdate()).thenReturn(1);
    assertEquals(daoImpl.sendToHistorical(), 1);

}