reduce controllers unit tests boiler-plate code

[ch4mpy]

Summary

Quite some Mock-Mvc requests configuration could be automatized. Additionally, The framework could provide with finer grained MockHttpServletRequestBuilder factories and even shortcuts to issue MockMvc requests in one call.

Most of these is not security related and if this request is ever accepted, you might split what is pure security from what is just MVC related (every-thing but Authorization header). But as security is involved and the solution I propose is part of set of OAuth2 unit testing improvements I request, here it is...

Actual Behavior

Content-type, Accept and Authorization headers are to be manually added to each MockMvc request. This is boring and error-prone (you can easily forget Authorization header or miss-match Content-type and actual body serialization mechanism).

Expected Behavior

As done in MockMvcHelper and OAuth2MockMvcHelper:

• Authorization header set when OAuth2 authentication is configured (test decorated with authentication meta-data)
• Content-Type header set for each POST, PUT and PATCH request
• Accept header set for each GET, POST and OPTION request

linked requests

• Ease controllers unit tests in OAuth2 secured apps #6557
• @WithMockUser alike annotations for OAuth2 #6558
• Have unit test OAuth2 authentication configured with annotations #6559

Sample

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()));
    }
}

In this sample:

• api is a MockMvc wrapper instance
• Authorization and Accept headers are transparently added
• MockHttpServletRequestBuilder is created, configured, build and performed in one call
• you can browse my source for additional samples involving further request builder configuration (cookies or additional headers)

P.S.

SerializationHelper, used in MockMvcHelper, quite eases requests body serializing using registered message converters. It might be worth being contributed to the framework too but don't quite know where...

[ch4mpy]

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