@WithMockUser alike annotations for OAuth2

[ch4mpy]

Summary

Provide with tooling to set-up properly mocked OAuth2Authentication when writing unit tests

Actual Behavior

@WithMockUser is not quite enough to mock Auth2 authentication

Expected Behavior

When I write controller unit tests, I wish I could mock any aspect of OAuth2 authentication (being direct client auth or on behalf of an end-user)

linked requests

• Ease controllers unit tests in OAuth2 secured apps #6557
• Have unit test OAuth2 authentication configured with annotations #6559
• reduce controllers unit tests boiler-plate code #6560

Sample

As described in this request, I came-up with a solution: @WithMockOAuth2Client to mock direct client connection and @WithMockOAuth2User to mock a client connected on behalf of an end-user (relies on both @WithMockOAuth2Client and @WithMockUser).

Overall result in controller unit tests:

@WebMvcTest(UserController.class)
@Import({ResourceServerConfig.class})
@EnableSpringDataWebSupport
public class UserControllerTest extends OAuth2ControllerTest {

    @MockBean
    UserRepository userRepo;

    @Test
    @WithMockOAuth2User(user = @WithMockUser(username = "admin", authorities = "READ_USERS"))
    public void whenAuthenticatedWithReadUserPrivilegeThenListUsersReturnsUsersPage() throws Exception {
        final List<User> users = Arrays.asList(admin, user);
        when(userRepo.findAll(any(Pageable.class))).thenAnswer(invocation ->
                new PageImpl<>(users, (Pageable) invocation.getArguments()[0], users.size()));

        api.get("/users/")
                .andExpect(status().isOk())
                .andExpect(jsonPath("$._embedded.elements", hasSize(users.size())))
                .andDo(document("users-collection",
                        ignorePage(responseFields(), "elements"),
                        links()));
    }
}

[ch4mpy]

merged 4 requests in first to better preserve the big picture of the need