Repository for legacy code meetup

Read More

Working with legacy code

---

Legend: You have legacy (without tests) service which calculates order amount. You've hired separate testing team. They worked hard some months and wrote acceptance tests.

---

Go down with test

class DeliveryControllerShould {

    @ParameterizedTest
    @CsvSource({
            "Обычный, 999, 1249",
            "Обычный, 1000, 1000",
            "VIP, 999, 999",
            "VIP, 2499, 2499",
            "VIP, 2500, 2375"
    })
    void calculateDeliveryFee(String clientType, Integer cartAmount, Integer orderAmount) {
        assertEquals(orderAmount, new DeliveryController().calculate(clientType, cartAmount));
    }
}

Refactoring

1. Add SpringTest:

    @SpringBootTest(webEnvironment= WebEnvironment.RANDOM_PORT)
    public class DeliveryServiceApprovalTest {
    
        @Autowired
        DeliveryController deliveryController;
    
        @Test
        void vipClientShouldNotPayForDelivery() {
            assertEquals(Integer.valueOf(2499), deliveryController.calculate("VIP", 2499));
        }
    }

1. Add TDD DeliveryServiceShould and create DeliverService.

    @Test
    void addDeliveryFeeToOrderAmount() {
            assertEquals(1249,deliveryService.calculate(999));
            }

@Test
    void NotAddDeliveryFeeToOrderAmountIfItIsEqualOrMoreThen1000(){
            assertEquals(1000,deliveryService.calculate(1000));
            }

1. Replace call in DeliveryContoller
2. Extract interface of DeliverService

ToDo

1. Обновить Spring framework до версии 6+, Spring boot до версии 3+ (учесть, что потребуется использовать Java 17 и Gradle 7.3+). -> done
2. Перейти на Kotlin в Gradle скриптах. -> done
3. Постепенный перенос проекта на Kotlin.