SpringBoot Junit testing for filters in Zuul

Question

I'm new to Zuul J-unit testing. I have a couple of filters which is ChangeRequestEntityFilter and SessionFilter, Where I pasted my filtercode below. Can someone tell me how to write a Junit for the filter. I've searched and trying to use MockWire for the unit testing(Also I pasted my empty methods with basic annotations and WireMock port). I need at-least one proper example how this J-unit for Zuul works. I've referred the http://wiremock.org/docs/getting-started/ doc. Where I got what to do, but not how to do.

public class ChangeRequestEntityFilter extends ZuulFilter {

    @Autowired
    private UtilityHelperBean utilityHelperBean;

    @Override
    public boolean shouldFilter() {
        // //avoid http GET request since it does'nt have any request body
        return utilityHelperBean.isValidContentBody();
    }

    @Override
    public int filterOrder() {
        //given priority
    }

    @Override
    public String filterType() {
        // Pre
    }

    @Override
    public Object run() {

        RequestContext context = getCurrentContext();

        try {
            /** get values profile details from session */
            Map<String, Object> profileMap = utilityHelperBean.getValuesFromSession(context,
                    CommonConstant.PROFILE.value());

            if (profileMap != null) {
                /** get new attributes need to add to the actual origin microservice request payload */
                Map<String, Object> profileAttributeMap = utilityHelperBean.getProfileForRequest(context, profileMap);
                /** add the new attributes in to the current request payload */
                context.setRequest(new CustomHttpServletRequestWrapper(context.getRequest(), profileAttributeMap));
            }

        } catch (Exception ex) {
            ReflectionUtils.rethrowRuntimeException(new IllegalStateException("ChangeRequestEntityFilter : ", ex));
        }

        return null;
    }

}

I know ,I'm asking more. But give me any simple working complete example, I'm fine with it.

My current code with basic annotations and WireMock port.

@RunWith(SpringRunner.class)
@SpringBootTest
@DirtiesContext
@EnableZuulProxy
public class ChangeRequestEntityFilterTest {

    @Rule
    public WireMockRule wireMockRule = new WireMockRule(8080);

    @Mock
    ChangeRequestEntityFilter requestEntityFilter;

    int port = wireMockRule.port();

    @Test
    public void changeRequestTest() {

    }
}

Answer 1

Have you tried @MockBean?

https://docs.spring.io/spring-boot/docs/current/api/org/springframework/boot/test/mock/mockito/MockBean.html

"When @MockBean is used on a field, as well as being registered in the application context, the mock will also be injected into the field. Typical usage might be:"

@RunWith(SpringRunner.class)
public class ExampleTests {

     @MockBean
     private ExampleService service;

     @Autowired
     private UserOfService userOfService;

     @Test
     public void testUserOfService() {
         given(this.service.greet()).willReturn("Hello");
         String actual = this.userOfService.makeUse();
         assertEquals("Was: Hello", actual);
     }

     @Configuration
     @Import(UserOfService.class) // A @Component injected with ExampleService
     static class Config {
     }

}

Answer 2

Here there is another approach:

    private ZuulPostFilter zuulPostFilter;

    @Mock
    private anotherService anotherService;

    @Mock
    private HttpServletRequest request;

    @Before
    public void before() {
        MockitoAnnotations.initMocks(this);
        MonitoringHelper.initMocks();
        zuulPostFilter = new ZuulPostFilter(anotherService);
        doNothing().when(anotherService).saveInformation(null, false);
    }

    @Test
    public void postFilterTest() {
        log.info("postFilterTest");
        RequestContext context = new RequestContext();
        context.setResponseDataStream(new ByteArrayInputStream("Test Stream".getBytes()));
        context.setResponseGZipped(false);
        RequestContext.testSetCurrentContext(context);
        when(request.getScheme()).thenReturn("HTTP");
        RequestContext.getCurrentContext().setRequest(request);

        ZuulFilterResult result = zuulPostFilter.runFilter();

        assertEquals(ExecutionStatus.SUCCESS, result.getStatus());
        assertEquals("post", zuulPostFilter.filterType());
        assertEquals(10, zuulPostFilter.filterOrder());
    }

In this case you can test the filter and mock the services inside it without having to autowire it, the problem with the @autowired is that if you have services inside the filter, then it is going to be an integration test that is going to be more difficult to implement.