[FIXED] MvcTest with mocks is integration test or unit test

Issue

If we have mocks in the MvcMock test on rest endpoint, can we call it as integration test? Definitely, I can say TestRestTemplate test is integration test as there is no mocking when I test the endpoint.

MvcMock test

@SpringBootTest
@AutoConfigureMockMvc
@ActiveProfiles("test")
internal class CreateProductRestControllerMvcTest {

    @Autowired
    private lateinit var mockMvc: MockMvc

    @Autowired
    private lateinit var objectMapper: ObjectMapper

    @MockkBean
    private lateinit var createProductService: CreateProductService

    @ParameterizedTest
    @ArgumentsSource(ValidCreateProductRequests::class)
    internal fun `POST a new Product, GIVEN without any exception, THEN return Product id and status 201`(request: CreateProductRequest) {
        // Given
        every { createProductService.invoke(request.toCommand()) } returns ProductId(1L)

        // When, Then
        this.mockMvc.post(REST_PRODUCTS) {
            contentType = APPLICATION_JSON
            content = objectMapper.writeValueAsString(request)
        }
            .andExpect {
                status { isCreated() }
                content { json((objectMapper.writeValueAsString(1L))) }
            }
    }
}

TestRestTemplate Test

@SpringBootTest(webEnvironment = RANDOM_PORT, classes = [Application::class])
@ActiveProfiles("test")
@Testcontainers
@FlywayTest
@ExtendWith(FlywayTestExtension::class)
class CreateProductRestControllerIntegrationTest {

    @Autowired
    private lateinit var restTemplate: TestRestTemplate

    private lateinit var headers: HttpHeaders

    @BeforeEach
    internal fun setUp() {
        headers = HttpHeaders()
        headers.contentType = MediaType.APPLICATION_JSON
    }


    @FlywayTest
    @ParameterizedTest
    @ArgumentsSource(ValidJsonRequestBodies::class)
    internal fun `POST new Product, GIVEN valid request, THEN returns 201`(json: String) {
        // Given
        val request: HttpEntity<String> = HttpEntity(json, headers)

        // When
        val result = restTemplate.postForEntity(REST_PRODUCTS, request, String::class.java);

        // Then
        assertNotNull(result.body)
        assertEquals(HttpStatus.CREATED, result.statusCode)
    }
}

Solution

In my opinion, calling it an "integration test" is not completely fair. By mocking the Service you are basically testing your Controller and testing the capability of serializing and deserializing JSON, which is a completely valid test.

In Spring world you might find these being called "slice tests" on which the point of the test is to check a given layer of your application instead of a fully-fledged integration test. More information about them in:

• https://docs.spring.io/spring-boot/docs/2.1.5.RELEASE/reference/html/boot-features-testing.html#boot-features-testing-spring-boot-applications-testing-autoconfigured-tests
• https://www.baeldung.com/spring-tests#5-using-test-slices
• https://dzone.com/articles/spring-boot-web-slice-test

Answered By - João Dias