为 spring MVC 单元测试不抛出 doThrow 异常？

Question

ive tried switch to a when() and get compiler errors

i have successfully used doThrow(...) in another test in the same project, so i dont know whats going on here

Unit test code:

doThrow(new Exception("the client cancelled the request, ya dingus!")).when(handler).write(any());

MvcResult result = mockMvc.perform(post("/myPath")
            .content(String.valueOf(mockValidRequest))
            .contentType(MediaType.APPLICATION_JSON)
            .characterEncoding("utf-8"))
            .andExpect(status().is5xxServerError())
            .andReturn();

Code I am testing (handler method for /myPath):

@PostMapping("/myPath")
public ResponseEntity<String> handleRequest(@RequestBody MyPojo request) {
 try {
        handler.write(request);
    } catch (Exception e) {
        return new ResponseEntity<>("Exception thrown during event processing: " + e, HttpStatus.SERVICE_UNAVAILABLE);
    }

return new ResponseEntity<>("Success", HttpStatus.OK)
}

The problem is the test says the actual result is a 200 success, when there should have been an exception caught, and a service unavailable 5xx response.

Answer 1

i found that i could get the tests to pass calling the function directly ... it just seems like MockMvc is not incorporating the doThrow logic

revised unit test:

doThrow(new Exception("some error")).when(handler).sendToSqsWriter(any());

ResponseEntity<String> response = controller.handleRequest(new Gson().fromJson(new JSONObject(mockApptRequestBody);.toString(), SeamAppointmentRequest.class));

assertTrue(response.toString().contains("some error"));
assertTrue(response.getStatusCodeValue() == 503);

all the json/gson jazz is resolving runtime parsing errors

Answer 2

So I found the proper answer to my issue:

I didnt have this snippet in my original post, but the handler was being instantiated in the test like this:

@Mock
EventHandler handler;

it needed to be:

@MockBean 
EventHandler handler;

My guess is since @MockBean is the spring mock, and @Mock is from Mockito, it was probably mocking an event handler that was instantiated outside of the Spring container. Thus why I didnt think it was picking up the doThrow ... it did pick it up, but spied on the wrong instance.