Spring Boot 1.4 Unit Test Hibernate Validation WebMvcTest

I am trying to perform a unit test in Spring Boot 1.4 to test my validation returns a 400 on an invalid query string parameter.

Controller

@RestController
@Validated
public class ExampleController {

    ...

    @RequestMapping(value = "/example", method = GET)
    public Response getExample(
            @RequestParam(value = "userId", required = true) @Valid @Pattern(regexp = MY_REGEX) String segmentsRequest {

        // Stuff here
    }

}

Exception Handler

@ControllerAdvice
@Component
public class GlobalExceptionHandler {

    private static final Logger logger = LoggerFactory.getLogger(GlobalExceptionHandler.class);

    // 400 - Bad Request
    @ExceptionHandler(value = {ConstraintViolationException.class})
    @ResponseStatus(HttpStatus.BAD_REQUEST)
    public void constrainViolationHandle(HttpServletRequest request, ConstraintViolationException exception) {
        logger.error("Error Bad Request (400)");
    }

}

Context

@Bean
public Validator validator() {
    final ValidatorFactory validatorFactory = Validation.byDefaultProvider()
            .configure()
            .parameterNameProvider(new ReflectionParameterNameProvider())
            .buildValidatorFactory();
    return validatorFactory.getValidator();
}

@Bean
public MethodValidationPostProcessor methodValidationPostProcessor() {
    final MethodValidationPostProcessor methodValidationPostProcessor = new MethodValidationPostProcessor();
    methodValidationPostProcessor.setValidator(validator());
    return methodValidationPostProcessor;
}

Unit Test

@RunWith(SpringRunner.class)
@WebMvcTest(ExampleController.class)
public class ExampleControllerTest {

    private static final String EMPTY = "";

    @Autowired
    private MockMvc mvc;

    @Test
    public void test() throws Exception {

        // Perform Request
        ResultActions response = this.mvc.perform(
            get("/example").param("userId", "invalid")
        );

        // Assert Result
        response.andExpect(status().isBadRequest())
                .andExpect(content().string(EMPTY));
    }

}

However when I run my test I get a 200 not a 400. The validation is not performed when I am running as an Application just not as a test.

I believe it may be due to it not picking up the two validation beans when performing the test? This validation works