Business layer production code

✅ Business Layer

• transaction and rollback
• test code will be an integrated test
• as it will test how business layer and persistence layer interacts

✅ Business Logic

• (1) We add products to order
• (2) Need order entity
• (3) As product and order has many to many relationship, need orderProduct entity
• (4) We will create order with product numbers
• So we need OrderCreateRequest with productNumbers as List
• (5) When we create an order, we will return OrderResponse

• with ProductResponse as a List

• (6) Order controller
• (7) Order service
• to be able to write test code for registeredDateTime,
• it should be passed on as parameter when creating order

• we will recieve OrderCreateRequest and return OrderResponse

• when we find products from productRepository to create orders
• if product number is the same, we will only find one product
• but we can have several same products in one order

• like several latte in one order

• (8) order repository

📌 Test code for Service

• we are using @SpringBootTest
• this is NOT transactional ❌
• does not rollback
• so we need tearDown() method to clean the data after each test

@ActiveProfiles("test")
@SpringBootTest
class OrderServiceTest {
    //all @Autowired

    //After each test, clean data
    //so that one test does not affect another
    @AfterEach
    void tearDown() {
        //productRepository.deleteAll();
        orderProductRepository.deleteAllInBatch();
        productRepository.deleteAllInBatch();
        orderRepository.deleteAllInBatch();
    }

• 🆚 In @DataJpaTest
• it has @Transactional ⭕️
• does rollback after each testt
• so no need for tearDown() method

@DataJpaTest //faster than spring, only brings JPA libraries
@ActiveProfiles("test") //do not use data.sql for test

class ProductRepositoryTest {
    @Autowired
    private ProductRepository productRepository;
}

📌 Test code for order class

• this will be unit test, as we are testing for each method

☑️ Testing with HTTP

• to test GET, we used h2-console and the api

• to test POST, we can use .http

• run the application

• then run .http file

• order.http

### create new order
POST localhost:8080/api/v1/orders/new
Content-Type: application/json

{
  "productNumbers": [
    "001", "002"
  ]
}

• product.http

### get products with status
GET localhost:8080/api/v1/products/selling

🔴 InvalidDefinitionException: Cannot construct instance of…

• this is because there is no constructor for request

• when making a POST request

• 🟢 Add constructor

@Getter
@NoArgsConstructor
public class OrderCreateRequest {
    private List<String> productNumbers;

    @Builder
    public OrderCreateRequest(List<String> productNumbers) {
        this.productNumbers = productNumbers;
    }
}