@WebMvcTest for controller testing in Spring Boot - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the @WebMvcTest annotation in Spring Boot?

@WebMvcTest is used to test Spring MVC controllers. It loads only the web layer, not the full application context, making tests faster and focused on controller behavior.

intermediate

Which Spring components are loaded when using @WebMvcTest?

Only the web layer components like controllers, @ControllerAdvice, Filter, and WebMvcConfigurer are loaded. Services, repositories, and other beans are not loaded unless explicitly mocked.

intermediate

How do you mock a service dependency in a @WebMvcTest controller test?

You use @MockBean to create a mock of the service and inject it into the controller during the test.

beginner

What is the role of MockMvc in @WebMvcTest?

MockMvc allows you to perform HTTP requests to the controller and verify responses without starting a real server.

beginner

Why is @WebMvcTest preferred over @SpringBootTest for controller tests?

@WebMvcTest loads only the web layer, making tests faster and more focused. @SpringBootTest loads the full application context, which is slower and less focused for controller testing.

What does @WebMvcTest load for testing?

A Only the web layer (controllers and related components)

B The full application context

C Only service and repository beans

D Only database connections

@WebMvcTest loads only the web layer, focusing on controllers and related MVC components.

Which annotation is used to mock a service in a @WebMvcTest?

A @Autowired

B @Component

C @Service

D @MockBean

@MockBean creates a mock of the service and injects it into the test context.

What is the main tool to perform HTTP requests in @WebMvcTest?

A MockMvc

B WebClient

C RestTemplate

D HttpClient

MockMvc simulates HTTP requests to controllers without starting a server.

Why might you prefer @WebMvcTest over @SpringBootTest for controller tests?

A It loads the full application context

B It is slower but more thorough

C It loads only the web layer, making tests faster

D It automatically tests the database

@WebMvcTest loads only the web layer, so tests run faster and focus on controller logic.

If your controller depends on a service, what must you do in a @WebMvcTest?

A Nothing, the service is loaded automatically

B Mock the service with <code>@MockBean</code>

C Use <code>@Autowired</code> on the service

D Use <code>@Service</code> on the test class

Services are not loaded automatically in @WebMvcTest. You must mock them with @MockBean.

Explain how @WebMvcTest helps in testing Spring Boot controllers and what you need to do to handle service dependencies.

Think about what parts of the app are loaded and how to provide missing parts.

Describe the difference between @WebMvcTest and @SpringBootTest when testing controllers.

Consider scope and speed of tests.