Код-ревью: интеграционный тест заказов

@SpringBootTest
@DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_EACH_TEST_METHOD)
@AutoConfigureTestDatabase
class OrderServiceTest {
    @Autowired OrderService service;
    @Autowired OrderRepository repo;
    @MockitoBean MailSender mail;

    @Test
    void createsOrder() throws Exception {
        service.create(new CreateOrder("anna@example.com", 500));
        Thread.sleep(3000);
        assertEquals(1, repo.count());
    }

    @Test
    void calculatesDiscount() {
        assertEquals(450, service.discounted(500, 10));
    }

    @Test
    void sendsMail() {
        service.create(new CreateOrder("anna@example.com", 500));
        verify(mail).send(any(), any());
    }
}