#ControllerAdvice not triggered on unit testing - spring-boot

Question

I need to test #ControllerAdvice methods which are in service layer. But I faced two issues:
ExceptionHandlers not triggered
And even if it would be triggered, I find out that don't now how to test it)
#Slf4j
#ControllerAdvice
public class AppExceptionHandler {
#ExceptionHandler(value = {.class})
public ResponseEntity<Object> handleMyException(MyException ex, WebRequest request) {
ErrorMessage errorMessage = ErrorMessage.builder()
.message(ex.getMessage())
.httpStatus(HttpStatus.BAD_REQUEST)
.time(ZonedDateTime.now())
.build();
return new ResponseEntity<>(errorMessage, HttpStatus.BAD_REQUEST);
}
#RunWith(MockitoJUnitRunner.class)
#RequiredArgsConstructor
public class MyExceptionTest {
private final AppExceptionHandler handler;
#Mock private final MyService service;
#Test
public void test() throws MyException {
when(service.create(any()))
.thenThrow(MyException .class);
}
}

Answer 1

For this purpose, you can write a test for your controller layer with #WebMvcTest as this will create a Spring Test Context for you that contains all #ControllerAdvice.
As your service is throwing this exception, you can mock the service bean with #MockBean and use Mockito to instruct your bean to throw the expected exception.
As I don't know how your controller looks like, the following is a basic example:
#RunWith(SpringRunner.class)
#WebMvcTest(MyController.class)
class PublicControllerTest {
#Autowired
private MockMvc mockMvc;
#MockBean
private MyService myService;
#Test
public void testException() throws Exception {
when(myService.create(any())).thenThrow(new MyException.class);
this.mockMvc
.perform(get("/public"))
.andExpect(status().isBadRequest());
}
}