unit test spring controller with WebTestClient and ControllerAdvice - junit

Question

I'm trying to unit test my controller and the specific case which is : my service return a Mono.Empty, I throw a NotFoundException and I wan't to make sure I'm getting a 404 exception
here's my controller :
#GetMapping(path = "/{id}")
public Mono<MyObject<JsonNode>> getFragmentById(#PathVariable(value = "id") String id) throws NotFoundException {
return this.myService.getObject(id, JsonNode.class).switchIfEmpty(Mono.error(new NotFoundException()));
}
Here's my controller advice :
#ControllerAdvice
public class RestResponseEntityExceptionHandler {
#ExceptionHandler(value = { NotFoundException.class })
protected ResponseEntity<String> handleNotFound(SaveActionException ex, WebRequest request) {
String bodyOfResponse = "This should be application specific";
return ResponseEntity.status(HttpStatus.NOT_FOUND).body("Resource not found");
}
}
and my test :
#Before
public void setup() {
client = WebTestClient.bindToController(new MyController()).controllerAdvice(new RestResponseEntityExceptionHandler()).build();
}
#Test
public void assert_404() throws Exception {
when(myService.getobject("id", JsonNode.class)).thenReturn(Mono.empty());
WebTestClient.ResponseSpec response = client.get().uri("/api/object/id").exchange();
response.expectStatus().isEqualTo(404);
}
I'm getting a NotFoundException But a 500 error not a 404 which mean my advice hasn't been called
stack trace :
java.lang.AssertionError: Status expected:<404> but was:<500>
> GET /api/fragments/idFragment
> WebTestClient-Request-Id: [1]
No content
< 500 Internal Server Error
< Content-Type: [application/json;charset=UTF-8]
Content not available yet
any idea ?

Answer 1

I believe you can delete this controller advice and just have the following:
#GetMapping(path = "/{id}")
public Mono<MyObject<JsonNode>> getFragmentById(#PathVariable(value = "id") String id) {
return this.myService.getObject(id, JsonNode.class)
.switchIfEmpty(Mono.error(new ResponseStatusException(HttpStatus.NOT_FOUND)));
}
As for ResponseEntityExceptionHandler, this class is part of Spring MVC so I don't think you should use it in a WebFlux application.