Spring Boot Test @PreAuthorize in a Library Module

I have a library-module written using Spring Boot 1.5.21.

The library has a @Service with some methods annotated with @PreAutorize allowing only users with ADMIN authority to perform some actions, for example a delete.

Then I have a Spring Boot Application that uses that library. If I run the app and manually test it, it works. Only ADMINs can delete. I'd like to write test for it.

I was thinking in writing separate test for module and for the main app. In my module I can successfully unit test the operations. But I'm having troubles testing the @PreAuthotize, because the security context does not exist in the module, but in the main app. Is there a way to test that annotation in the module, and not in the main app?

The relevant code of my library:

@Service
public class MyService {
    @PreAuthorize("hasAuthority('ADMIN')")
    public void delete (long id){
       .....
    }
}

@RunWith(SpringRunner.class)
public class MyServiceTest {

    private MyService service;


    @Test
    @WithAnonymousUser
    public void deleteShouldFailIfAnonymous() {
         ... Verify exception thrown
    }


    @Test
    @WithMockUser(authorities = 'USER')
    public void deleteShouldFailIfNotAdmin() {
         ... Verify exception thrown
    }

    @Test
    @WithMockUser(authorities = 'ADMIN')
    public void deleteShouldPass() {
         ... Should pass
    }
}

I've trying adding @EnableGlobalMethodSecurity(prePostEnabled = true) but with no luck. And as said, the SecurityConfiguration is loaded in the main app, it does not exist in the library-module.

Can I test the @PreAuthorize in the module or should I move it to the main app? I'd like to have it i the module if possible. Or maybe I can create a Context only for testing, but don't know how to do it.

You can use the MockMvc to test. This will help with module testing incase of integration testing.

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration
@WebAppConfiguration
public class SecurityTests {

    @Autowired
    private WebApplicationContext context;

    private MockMvc mvc;

    @Before
    public void setup() {
        mvc = MockMvcBuilders.webAppContextSetup(context).apply(springSecurity()).build();
    }

    @WithMockUser(roles="ADMIN")
    @Test
    public void withMockUser() {
        mvc.perform(get("......"))

    }
}

Aspect-oriented features like @PreAuthorize are implemented as advice. Usually, this means that Spring will create a decorator interface that intercepts the method call, performs the advice (in this case, checking the condition and throwing an exception if it fails), and then sends the call on to the service object.

When you use new MyService, you're creating a bare object without the wrappers that implement the advice, so you won't see security, validation, caching, etc., applied. To see the behavior you want, you need to make your test bean @Autowired using the Spring test support.