M04 Q42 When do you want to use @WebMvcTest? What does it auto-configure?

You should use @WebMvcTest annotation when you want to write Integration Test that is focused on web layer of your application. @WebMvcTest approach will create ApplicationContext that contains only web components and omits any other components that are not part of web layer. Other components, if required for the test, can be mocked with usage of @MockBean annotation or delivered by @Configuration annotated class imported with usage of @Import annotation.

@WebMvcTest supports two cases:

Single Controller Auto-Configuration – annotate test by providing Controller class - @WebMvcTest(CityController.class)

Multiple (All found) Controllers Auto-Configuration – just annotate test with @WebMvcTest

@WebMvcTest annotation will auto-configure:

Mock Mvc
@Controller annotated class
@ControllerAdvice annotated class
@JsonComponent annotated class
@Converter annotated class
@GenericConverter annotated class
@Filter annotated class
@WebMvcConfigurer annotated class
@HandlerMethodArgumentResolver annotated class