SpringBoot Detail is not localized when problemdetails enabled

@RestController
@SpringBootApplication
public class DemoApplication {

    @RequestMapping("/")
    String home() {
        throw new ResponseStatusException(BAD_REQUEST, "bad.request");
    }

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }

}

@SpringBootTest(webEnvironment= SpringBootTest.WebEnvironment.RANDOM_PORT)
@TestPropertySource(properties = {"spring.mvc.problemdetails.enabled=true"})
class ProblemDetailsTests {

    @Autowired
    private TestRestTemplate testRestTemplate;

    @Autowired
    private MessageSource messageSource;
    @Test
    void detailShouldBeLocalized() {
        ResponseEntity<Map<String, Object>> resp = testRestTemplate.exchange(RequestEntity.method(GET, "/").build(),
                new ParameterizedTypeReference<Map<String, Object>>() {
                });
        assertThat(resp.getBody().get("detail")).isEqualTo(messageSource.getMessage("bad.request",null,null)); // failed
    }

}

@SpringBootTest(webEnvironment= SpringBootTest.WebEnvironment.RANDOM_PORT)
class ErrorAttributesTests {

    @Autowired
    private TestRestTemplate testRestTemplate;

    @Autowired
    private MessageSource messageSource;
    @Test
    void messageShouldBeLocalized() {
        ResponseEntity<Map<String, Object>> resp = testRestTemplate.exchange(RequestEntity.method(GET, "/").build(),
                new ParameterizedTypeReference<Map<String, Object>>() {
                });
        assertThat(resp.getBody().get("message")).isEqualTo(messageSource.getMessage("bad.request",null,null)); // passed
    }

}

detail should be localized like traditional message. Here is test project demo.zip

Comment From: wilkinsona

Localisation of problem details is handled by Spring Framework and, therefore, is out of Spring Boot's control. As you have seen it doesn't localise the reason. Instead, it uses the message detail code. I believe that this will work:

throw new ResponseStatusException(BAD_REQUEST, "bad.request") {

    @Override
    public String getDetailMessageCode() {
        return "bad.request";
    }

};

If you think that the localisation support could be improved, please open a Spring Framework issue.