Testing Spring MVC @ExceptionHandler method with S

Question

I have the following simple controller to catch any unexpected exceptions:

@ControllerAdvice
public class ExceptionController {

    @ExceptionHandler(Throwable.class)
    @ResponseStatus(value = HttpStatus.INTERNAL_SERVER_ERROR)
    @ResponseBody
    public ResponseEntity handleException(Throwable ex) {
        return ResponseEntityFactory.internalServerErrorResponse("Unexpected error has occurred.", ex);
    }
}

I'm trying to write an integration test using Spring MVC Test framework. This is what I have so far:

@RunWith(MockitoJUnitRunner.class)
public class ExceptionControllerTest {
    private MockMvc mockMvc;

    @Mock
    private StatusController statusController;

    @Before
    public void setup() {
        this.mockMvc = MockMvcBuilders.standaloneSetup(new ExceptionController(), statusController).build();
    }

    @Test
    public void checkUnexpectedExceptionsAreCaughtAndStatusCode500IsReturnedInResponse() throws Exception {

        when(statusController.checkHealth()).thenThrow(new RuntimeException("Unexpected Exception"));

        mockMvc.perform(get("/api/status"))
                .andDo(print())
                .andExpect(status().isInternalServerError())
                .andExpect(jsonPath("$.error").value("Unexpected Exception"));
    }
}

I register the ExceptionController and a mock StatusController in the Spring MVC infrastructure. In the test method I setup an expectation to throw an exception from the StatusController.

The exception is being thrown, but the ExceptionController isn't dealing with it.

I want to be able to test that the ExceptionController gets exceptions and returns an appropriate response.

Any thoughts on why this doesn't work and how I should do this kind of test?

Thanks.

Answer 1

This is better:

((HandlerExceptionResolverComposite) wac.getBean("handlerExceptionResolver")).getExceptionResolvers().get(0)

And do not forget to scan for @ControllerAdvice beans in your @Configuration class:

@ComponentScan(basePackages = {"com.company.exception"})

...tested on Spring 4.0.2.RELEASE

Answer 2

Use Spring MockMVC to emulate a servletContainer to a point where you can incorporate any request filtering or exception handling tests in your unit tests suite.

You can configure this setup with the following approach:

Given a custom RecordNotFound exception...

@ResponseStatus(value=HttpStatus.NOT_FOUND, reason="Record not found") //
public class RecordNotFoundException extends RuntimeException {

    private static final long serialVersionUID = 8857378116992711720L;

    public RecordNotFoundException() {
        super();
    }

    public RecordNotFoundException(String message) {
        super(message);
    }
}

... and a RecordNotFoundExceptionHandler

@Slf4j
@ControllerAdvice
public class BusinessExceptionHandler {

    @ExceptionHandler(value = RecordNotFoundException.class)
    public ResponseEntity<String> handleRecordNotFoundException(
            RecordNotFoundException e,
            WebRequest request) {
         //Logs
        LogError logging = new LogError("RecordNotFoundException",
                HttpStatus.NOT_FOUND, 
                request.getDescription(true));
        log.info(logging.toJson());

        //Http error message
        HttpErrorResponse response = new HttpErrorResponse(logging.getStatus(), e.getMessage());
        return new ResponseEntity<>(response.toJson(),
                HeaderFactory.getErrorHeaders(),
                response.getStatus());
    }
   ...
}

Configure a tailored test context: set a @ContextConfiguration to specify the classes you need for your test. Set Mockito MockMvc as a servlet container emulator and set your tests fixture and dependencies.

 @RunWith(SpringRunner.class)
@ContextConfiguration(classes = {
    WebConfig.class,
    HeaderFactory.class,
})
@Slf4j
public class OrganisationCtrlTest {

    private MockMvc mvc;

    private Organisation coorg;

    @MockBean
    private OrganisationSvc service;

    @InjectMocks
    private OrganisationCtrl controller = new OrganisationCtrl();

    //Constructor
    public OrganisationCtrlTest() {
    }
   ....

Configure a mock MVC "servlet emulator": register handler beans in the context and build the mockMvc emulator (Note: there are two possible configuration: standaloneSetup or webAppContextSetup; refer to the documentation). The builder rightfully implements the Builder pattern so you can chain configuration commands for exception resolvers and handlers before calling build().

    @Before
    public void setUp() {
        final StaticApplicationContext appContext = new StaticApplicationContext();
        appContext.registerBeanDefinition("BusinessExceptionHandler",
                new RootBeanDefinition(BusinessExceptionHandler.class, null, null));

//InternalExceptionHandler extends ResponseEntityExceptionHandler to //handle Spring internally throwned exception
        appContext.registerBeanDefinition("InternalExceptionHandler",
                new RootBeanDefinition(InternalExceptionHandler.class, null,
                        null));
        MockitoAnnotations.initMocks(this);
        mvc = MockMvcBuilders.standaloneSetup(controller)
                .setHandlerExceptionResolvers(getExceptionResolver(appContext))
                .build();
        coorg = OrganisationFixture.getFixture("orgID", "name", "webSiteUrl");
    }
    ....

Get the exception resolver

private ExceptionHandlerExceptionResolver getExceptionResolver(
        StaticApplicationContext context) {
    ExceptionHandlerExceptionResolver resolver = new ExceptionHandlerExceptionResolver();
    resolver.getMessageConverters().add(
            new MappingJackson2HttpMessageConverter());
    resolver.setApplicationContext(context);
    resolver.afterPropertiesSet();
    return resolver;
}

Run your tests

    @Test
    public void testGetSingleOrganisationRecordAnd404() throws Exception {
        System.out.println("testGetSingleOrganisationRecordAndSuccess");
        String request = "/orgs/{id}";
        log.info("Request URL: " + request);

        when(service.getOrganisation(anyString())).
                thenReturn(coorg);
        this.mvc.perform(get(request)
                .accept("application/json")
                .andExpect(content().contentType(
                        .APPLICATION_JSON))
                .andExpect(status().notFound())
                .andDo(print());
    }
    ....
}

Hope this helps.

Jake.

Answer 3

I just had the same issue and the following works for me:

@Before
public void setup() {
    this.mockMvc = MockMvcBuilders.standaloneSetup(statusController)
         .setControllerAdvice(new ExceptionController())
        .build();
}

Answer 4

Since you are using stand alone setup test you need to provide exception handler manually.

mockMvc= MockMvcBuilders.standaloneSetup(adminCategoryController).setSingleView(view)
        .setHandlerExceptionResolvers(getSimpleMappingExceptionResolver()).build();

I had same problem a few days back, you can see my problem and solution answered by myself here Spring MVC Controller Exception Test

Hoping my answer help you out

Answer 5

This code will add ability to use your exceptions controlled advice.

@Before
public void setup() {
    this.mockMvc = standaloneSetup(commandsController)
        .setHandlerExceptionResolvers(withExceptionControllerAdvice())
        .setMessageConverters(new MappingJackson2HttpMessageConverter()).build();
}

private ExceptionHandlerExceptionResolver withExceptionControllerAdvice() {
    final ExceptionHandlerExceptionResolver exceptionResolver = new ExceptionHandlerExceptionResolver() {
        @Override
        protected ServletInvocableHandlerMethod getExceptionHandlerMethod(final HandlerMethod handlerMethod,
            final Exception exception) {
            Method method = new ExceptionHandlerMethodResolver(ExceptionController.class).resolveMethod(exception);
            if (method != null) {
                return new ServletInvocableHandlerMethod(new ExceptionController(), method);
            }
            return super.getExceptionHandlerMethod(handlerMethod, exception);
        }
    };
    exceptionResolver.afterPropertiesSet();
    return exceptionResolver;
}

Answer 6

Try it;

@RunWith(value = SpringJUnit4ClassRunner.class)
@WebAppConfiguration
@ContextConfiguration(classes = { MVCConfig.class, CoreConfig.class, 
        PopulaterConfiguration.class })
public class ExceptionControllerTest {

    private MockMvc mockMvc;

    @Mock
    private StatusController statusController;

    @Autowired
    private WebApplicationContext wac;

    @Before
    public void setup() {
        this.mockMvc = MockMvcBuilders.webAppContextSetup(this.wac).build();
    }

    @Test
    public void checkUnexpectedExceptionsAreCaughtAndStatusCode500IsReturnedInResponse() throws Exception {

        when(statusController.checkHealth()).thenThrow(new RuntimeException("Unexpected Exception"));

        mockMvc.perform(get("/api/status"))
                .andDo(print())
                .andExpect(status().isInternalServerError())
                .andExpect(jsonPath("$.error").value("Unexpected Exception"));
    }
}