3-Tier-Architecture 테스트 코드 작성하기 (1)

13:58:04.924 [Test worker] INFO com.example.solcoupang.TestLifeCycle -- --BeforAll 호출
13:58:04.934 [Test worker] INFO com.example.solcoupang.TestLifeCycle -- --BeforEach 호출
13:58:04.935 [Test worker] INFO com.example.solcoupang.TestLifeCycle -- --test 시작
13:58:04.935 [Test worker] INFO com.example.solcoupang.TestLifeCycle -- --afterEach 호출
13:58:04.937 [Test worker] INFO com.example.solcoupang.TestLifeCycle -- --BeforEach 호출
13:58:04.937 [Test worker] INFO com.example.solcoupang.TestLifeCycle -- --displayNameTest 시작
13:58:04.937 [Test worker] INFO com.example.solcoupang.TestLifeCycle -- --afterEach 호출
13:58:04.938 [Test worker] INFO com.example.solcoupang.TestLifeCycle -- --AfterAll 호출

@RestController
@RequiredArgsConstructor
@RequestMapping("/api/v1/products")
@Slf4j
public class ProductControllerV1 {

    private final ProductService productService;

    @GetMapping(value = "/{productId}")
    public BaseResponse<ProductDto> getProductDetail(@PathVariable Long productId){
        ProductDto productDto = productService.findByProductId(productId);
        return new BaseResponse(productDto);
    }
}

@WebMvcTest(ProductControllerV1.class) //슬라이스 테스트
//@RequiredArgsConstructor
public class ProductControllerTest {
    private final MockMvc mockMvc;
    @Autowired
    public ProductControllerTest(MockMvc mockMvc) { // Mock 객체 불러오기
        this.mockMvc = mockMvc;
    }
    // 서비스 Mock 객체 만들기
    @MockBean
    ProductService productService;
    @Test
    @DisplayName("Mock MVC를 통한 Product 데이터 가져오기 테스트")
    void getProductDetail() throws Exception{ // 서비스 Mock 객체의 입출력 선언

      // 컨트롤러가 사용하는 Mock ProductService 객체를 선언
        given(productService.findByProductId(1L))
                .willReturn(
                        ProductDto.builder().productId(1L)
                                .productName("test1")
                                .sellerId(1L)
                                .registrationDate(LocalDate.parse("2023-11-16"))
                                .countryOfManufacture("한국")
                                .weight(1000L)
                                .kcCertificationInformation("한국 : 응! 인정!")
                                .manufacturer("당근")
                                .importer("한국물류")
                                .productContentDtoList(List.of("https:s3//djsfdl","https:s3//djsfdl","https:s3//djsfdl"))
                                .build()
                );

        String productId = "1";

        mockMvc.perform(
                get("/api/v1/products/detail/"+productId) // Controller에 입력 선언
        ).andExpect(status().isOk()) // Controller 출력 검증
                .andExpect(jsonPath("$.isSuccess").exists())
                .andExpect(jsonPath("$.productId").exists())
                .andExpect(jsonPath("$.sellerId").exists())
                .andDo(print());

        verify(productService).findByProductId(1L); // findByProductId 메서드가 실행됐는지 확인
    }
}

MockHttpServletResponse:
           Status = 200
    Error message = null
          Headers = [Content-Type:"application/json"]
     Content type = application/json
             Body = {"isSuccess":true,"code":"OK","message":"요청에 성공하였습니다.","result":{"productId":1,"sellerId":1,"registrationDate":"2023-11-16","productName":"test1","countryOfManufacture":"한국","weight":1000,"kcCertificationInformation":"한국 : 응! 인정!","manufacturer":"당근","importer":"한국물류","productContentDtoList":["https:s3//djsfdl","https:s3//djsfdl","https:s3//djsfdl"]}}
    Forwarded URL = null
   Redirected URL = null
          Cookies = []
java.lang.AssertionError: No value at JSON path "$.productId"

mockMvc.perform(
                get("/api/v1/products/detail/"+productId)
        ).andExpect(status().isOk())
                .andExpect(jsonPath("$.isSuccess").exists())
                .andExpect(jsonPath("$.result.productId").exists())
                .andExpect(jsonPath("$.result.sellerId").exists())
                .andDo(print());

@Service
@RequiredArgsConstructor
public class ProductService {
    private final ProductDao productDao;
    private final ProductRepository productRepository;

    public ProductDto findByProductId(Long id){
        Product product = productRepository.findByProductIdWithFetch(id);
        return ProductDto.fromEntity(product);
    }
}

public class ProductServiceTest { // 단위 테스트, 외부 연결 X

    private ProductRepository productRepository = Mockito.mock(ProductRepository.class);
    private ProductServiceV2 productService;

    @BeforeEach
    public void setUpTest(){ // ProductServiceV2 객체 생성을 위한 생성자를 통한 DI
        productService = new ProductServiceV2(productRepository);
    }

    @Test
    void getProductByIdTest(){
        Seller seller = Seller.builder()
                .sellerId(1L)
                .build();

        Product givenProduct = Product.builder()
                .productId(1L)
                .seller(seller)
                .productName("삼애성플")
                .productContents(new ArrayList<>())
                .build();

        // Repository 객체의 동작을 가정한다.
        Mockito.when(productRepository.findByProductIdWithFetch(1L))
                .thenReturn(givenProduct);

        // Serivce 객체 결과값 얻기
        ProductDto productDto = productService.findByProductId(1L);

        // 결과값과 기대값 비교
        assertEquals(productDto.getProductId(), givenProduct.getProductId());
        assertEquals(productDto.getProductName(), givenProduct.getProductName());
        assertEquals(productDto.getSellerId(), givenProduct.getSeller().getSellerId());

        // 메서드 사용했는지 확인
        verify(productRepository).findByProductIdWithFetch(1L);
    }
}