Spring Mock Test return null body with CompletableFuture-CodePudding

i'm trying to make some tests for my rest api but when i start the first test the response body is null and i think it's because i am using CompletableFuture...

@SpringBootTest
@AutoConfigureMockMvc
@ExtendWith(SpringExtension.class)
public class UserControllerTests {

    @Autowired
    private MockMvc mockMvc;

    @InjectMocks
    private UserRestController controller;

    @Test
    @WithMockUser(username = "test", password = "test", roles = "ADMIN")
    public void tryGetAllUsers_shouldFindAllUsers() throws Exception {
        mockMvc.perform(get("/api/v1/user/all").accept(MediaType.APPLICATION_JSON))
                .andExpect(status().isOk())
                .andDo(print());
    }
}

Controller class

@GetMapping("/all")
    @RolesAllowed("ADMIN")
    @ResponseBody
    public CompletableFuture<ResponseEntity<Page<User>>> getUsers(@PageableDefault(sort = "id", direction = Sort.Direction.ASC) Pageable pageable) {
        return CompletableFuture.supplyAsync(() -> ResponseEntity.ok(service.getUsers(pageable)));
    }

I've tried so many ways and asked to so many people but one month later i got no solutions...

CodePudding user response：

Your CompletableFuture is executed but you never retrieve the value using the get() or join() method, note that these methods wait for your Supplier to return a value (but will also block your getUsers execution until the supplier's return).

Your method currently returns a reference to the CompletableFuture object (printed java.util.concurrent.CompletableFuture@c4437c4[Not completed]), thus the body is considered as null.

Based on the looks of your Controller, you should take a look at Spring's WebFlux which is an implementation of the reactive paradigm. More details can be found on the reactor project documentation

CodePudding user response：

You can make MockMvc to wait for your async response. change the code like this:

public void tryGetAllUsers_shouldFindAllUsers() throws Exception {
    MvcResult mvcResult = mockMvc.perform(MockMvcRequestBuilders.get("/api/v1/user/all")
            .accept(MediaType.APPLICATION_JSON))
            .andExpect(request().asyncStarted())
            .andReturn();

    mockMvc
            .perform(asyncDispatch(mvcResult))
            .andExpect(status().isOk())
            .andDo(print());

}