Testing Data Persistence with DataJpaTest

@DataJpaTest
class CustomerRepositoryTest {
 
    @Autowired
    private TestEntityManager entityManager;
 
    @Autowired
    private CustomerRepository repository;
 
    @Test
    void shouldFindCustomerByEmail() {
        Customer customer = new Customer("[email protected]");
        entityManager.persistAndFlush(customer);
 
        Optional<Customer> result = repository.findByEmail("[email protected]");
        Assertions.assertTrue(result.isPresent());
    }
}