Spring CrudRepository deleteAll() does nothing

Question

Testing a Controller class when i try do to delete all records from my database via Spring's CrudRepository, but it seems like nothing is happening. It seems is not flushing by default.

I've never tried this repository in a real controller call in a browser just with Junit tests, but I think it would works fine! :)

@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
@AutoConfigureMockMvc
@ActiveProfiles("test")
@Transactional
public class CostumerControllerIntegrationTest {

    @Autowired
    private MockMvc mockMvc;

    @Autowired
    private CostumerService costumerService;

    private Costumer costumer;

    @Before
    public void before() {
        this.costumer = this.exampleBuilder();
        costumerService.saveAll(this.costumer);
    }

    @After
    public void after() {
        costumerService.deleteAll();
    }

    @Test
    public void Should_ReturnStandardError_When_NotFoundById() throws Exception {
        //implementation
    }


private Costumer exampleBuilder() {

    Costumer costumer = new Costumer("Test", "Test", "Test", CostumerType.LEGAL_PERSON);
    State state = new State("Example State");
    City city = new City("Example Sity", state);
    Address address = new Address("Example Address",
            "Example Address", "Example Address",
            "Example Address", city, costumer);

    costumer.getAddresses().add(address);

    return costumer;
}

}

@Service
@Transactional
public class CostumerService {

    @Autowired
    private CostumerRepository repository;

    public void deleteAll() {
        repository.deleteAll();
    }

   //another methods

}

The repository extending CrudRepository

@Repository
public interface CostumerRepository extends CrudRepository<Costumer, Integer> {

}

After enable to show sql hibernate.show_sql=true based on @TheCoder comment, the result is:

The deleteAll() on @After:

@After
public void after() {
    costumerService.deleteAll();
}

The output sql:

2019-02-27 06:07:06 - HHH000397: Using ASTQueryTranslatorFactory
Hibernate: 
    select
        costumer0_.id as id1_3_,
        costumer0_.cpf_cnpj as cpf_cnpj2_3_,
        costumer0_.email as email3_3_,
        costumer0_.name as name4_3_,
        costumer0_.type as type5_3_ 
    from
        costumers costumer0_

The deteleAll() on @AfterTransaction the output sql includes the delete query.

@AfterTransaction
    public void afterTransatcion(){
        // List<Costumer> costumers = costumerService.findAll();
        costumerService.deleteAll();
    }


Hibernate: 
    select
        costumer0_.id as id1_3_,
        costumer0_.cpf_cnpj as cpf_cnpj2_3_,
        costumer0_.email as email3_3_,
        costumer0_.name as name4_3_,
        costumer0_.type as type5_3_ 
    from
        costumers costumer0_
Hibernate: 
    delete 
    from
        phones 
    where
        costumer_id=?
Hibernate: 
    delete 
    from
        costumers 
    where
        id=?

Answer 1

In my junit, after adding repository.deleteAllInBatch() inside @BeforeEach method worked for me. Faced this issue only during execution of junit.

@BeforeEach
public void config()
{
   repository.deleteAllInBatch()
}