I'm trying to test my spring OAuth2 authorization and authentication in my spring boot application using spring's MockMvc class. The fundamental issue I'm facing is the fact that my custom authentication provider is never called even if I have registered it as one of the authentication providers used by spring security. I followed the spring security tutorial found here and here.
Code snippet: Security configurer class - this is where the custom authentication provider gets added.
@Configuration
@EnableWebSecurity
public class SecurityConfigurer extends WebSecurityConfigurerAdapter {
    @Autowired
    private AuthenticationProvider authenticationProvider;
    @Override
    public void configure(AuthenticationManagerBuilder auth) {
        auth.authenticationProvider(authenticationProvider);
    }
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
                .authorizeRequests()
                .anyRequest().authenticated()
                .and()
                .httpBasic();
    }
}
Custom authentication provider - This should do the actual authentication
@Component
public class UsernamePasswordAuthProvider implements AuthenticationProvider {
    @Override
    public Authentication authenticate(Authentication authentication) throws AuthenticationException {
        String username = authentication.getName();
        String password = authentication.getCredentials()
                .toString();
        if ("test".equals(username) && "test".equals(password)) {
            Collection<? extends GrantedAuthority> grantedAuthorityList = authentication
                    .getAuthorities();
            return new UsernamePasswordAuthenticationToken
                    (username, password, grantedAuthorityList);
        } else {
            throw new
                    BadCredentialsException("External system authentication failed");
        }
    }
    @Override
    public boolean supports(Class<?> auth) {
        return true;
    }
}
Spring boot integration test - This is where MockMvc gets instantiated using the web application context
@RunWith(SpringRunner.class)
@SpringBootTest(classes = ConfigurationServiceApplication.class)
public class SettingsAPITest {
    private MockMvc mockMvc;
    @Autowired
    private WebApplicationContext wac;
    @Autowired
    private FilterChainProxy springSecurityFilterChain;
    @Before
    public void setup() {
        this.mockMvc = MockMvcBuilders.webAppContextSetup(this.wac)
                .addFilter(springSecurityFilterChain).build();
    }
    @Test 
    public void testGetStatus() throws Exception {
        //execute test
        mockMvc.perform(get("/status")
                .with(httpBasic("test","test")))
                .andDo(print())
                .andExpect(status().isOk());
    }
}
And here is the controller
@RestController
public class StatusController{
    @RequestMapping(method = RequestMethod.GET)
    public ResponseEntity<String> getStatus(){
        return new ResponseEntity<>("I'm Ok", HttpStatus.OK);
    }
}
Running the test returns 401 and putting a break point and debugging through it reveals that the custom authentication provider is never used.
MockHttpServletRequest:
      HTTP Method = GET
      Request URI = /status
       Parameters = {}
          Headers = {Authorization=[Basic dGVzdDp0ZXN0]}
Handler:
             Type = null
Async:
    Async started = false
     Async result = null
Resolved Exception:
             Type = null
ModelAndView:
        View name = null
             View = null
            Model = null
FlashMap:
       Attributes = null
MockHttpServletResponse:
           Status = 401
    Error message = null
          Headers = {X-Content-Type-Options=[nosniff], X-XSS-Protection=[1; mode=block], Cache-Control=[no-cache, no-store, max-age=0, must-revalidate, no-store], Pragma=[no-cache, no-cache], Expires=[0], X-Frame-Options=[DENY], WWW-Authenticate=[Bearer realm="oauth2-resource", error="unauthorized", error_description="Full authentication is required to access this resource"], Content-Type=[application/json;charset=UTF-8]}
     Content type = application/json;charset=UTF-8
             Body = {"error":"unauthorized","error_description":"Full authentication is required to access this resource"}
    Forwarded URL = null    Redirected URL = null
          Cookies = []
java.lang.AssertionError: Status  Expected :200 Actual   :401
I have a feeling that my webapp context configuration is being overriden by spring boot somewhere (as most of the stuff here is autoconfigured by spring boot), but I can't really justify this. Any help is really appreciated!! Thanks
FYI, I have looked at related posts