Junit Test JsonProcessingException

[Senad Delic]

Hi,

I have problem testing

JsonProcessingException

, can someone help me please?

Here is the code I want to test:

@GetMapping("/find-something")
    public Something findSomething(@RequestParam String exampleString) throws CustomExceptionWeb, JsonProcessingException {
        CustomClass customClass = objectMapper.readValue(exampleString, CustomClass.class);
        return serviceWeb.findBy(customClass);
    }

Here is the test method :

private static final String BASE_URL = "/sample/api/example/find-something";

@Autowired
    private MockMvc mvc;

 @MockBean
    private ObjectMapper objectMapper;

@Test
void expectToThrowWhenParamIsInvalid() throws Exception {
final String ueryParams = "?customFakeName=\"\"name\":\"fakeItTillYouMakeIt\:\"desc\"\"\n";


when(objectMapper.readValue(anyString(), eq(CustomClas.class))).thenThrow(JsonProcessingException.class);
        RequestBuilder requestBuilder = MockMvcRequestBuilders.get(BASE_URL + ueryParams);

        try {
            mvc.perform(requestBuilder);
            fail();
        } catch (NestedServletException e) {
            System.out.println("Testing = " + e.getRootCause());
            assertTrue(e.getRootCause() instanceof JsonProcessingException);
        }
}

When I'm testing RuntimeException, test is ok, but when testing JsonProcessingException it's printing error :

com.fasterxml.jackson.core.JsonProcessingException: N/A

My goal is to send invalid request param so when objectmapper start mapping json string in CustomClass to throw JsonProcessingException or IoException.
When i change starting

ueryParams = "?customFakeName="

in this "

?customFakeName:"

its going to throw this warnign:

MissingServletRequestParameterException: Required request parameter 'customFakeName' for method parameter type String is not present] 

Tnx

[Himai Minh]

Are you hard coding the customFakeName parameter? If so , try this:

ueryParams = "?customFakeName=name&fakeItTillYouMakeI=desc\n"

[Senad Delic]

Hi Himai,
I tried that also, it didn't work.
I'm caching RuntimeException but not JsonProcessingException

[Himai Minh]

Hi,
What other details printed on the console regarding to this RuntimeException?

[Tim Cooke]

Exceptions from controller mappings can not be handled in the way you are expecting when testing with MockMvc. Any exception thrown from a controller mapping method will be received in your test as a 500 HTTP response. So instead of a try catch arrangement you'll need to do something like this

mvc.perform(requestBuilder).andExpect(status().isInternalServerError());