Spring启动单元测试由Junit 5为什么mock返回null

Question

这是我的控制器:-

@RestController
@RequestMapping(ScoreBoardController.REQUEST_URL)
public class ScoreBoardController {
public static final String REQUEST_URL = "/score";       
public static final String POST_REQUEST = "/add";
public static final String GET_ALL_REQUEST = "/all";
public static final String DELETE_BY_ID = "/deleteById/{id}";
public static final String DELETE_BY_NAME = "/deleteByName/{name}";
public static final String DELETE_BY_ROUND_PATH_VAR = "/deleteByRoundPath/{round}";
public static final String DELETE_BY_ROUND_PARAM = "/deleteByRoundParam";
public static final String UPDAATE_NAME_BY_ID_PATH_VAR = "/updateNameByIdPath/{id}/{name}";
public static final String UPDATE_NAME_BY_ID_PARAM = "/updateNameByIdParam";
public static final String UPDATE_RESULT_BY_ID_PATH_VAR = "/updateResultByIdPath/{id}/{result}";
public static final String UPDATE_RESULT_BY_ID_PARAM = "/updateResultByIdParam";
public static final String GET_BY_ID = "/getById/{id}";
private ScoreService scoreService;
public ScoreBoardController(ScoreService scoreBoardService) {
this.scoreService = scoreBoardService;
}

@ApiOperation(value = "Add a new score post socre as json body")
@PostMapping(path = POST_REQUEST, produces = MediaType.APPLICATION_JSON_VALUE)
public Score save(
@ApiParam(value = "A score to save into db")
@RequestBody Score score) {
return scoreService.save(score);
}
}

服务:

@Service
public class ScoreService {
@Autowired
private ScoreRepository scoreRepository;
public Score save(Score score) {
return scoreRepository.save(score);
}
}

它工作，如果我POST请求邮差

http://localhost: 8080/分/添加

{
"name": "test4",
"round": 4,
"result": "WIN"
}

将数据保存在DB中，响应相同的分数。

但是我正试着按如下方式进行单元测试，这并不像预期的那样工作。

@WebMvcTest({ScoreBoardController.class})
class ScoreBoardControllerTest {
@MockBean
private ScoreService scoreService;
@Autowired
private MockMvc mockMvc;

@Test
void save() throws Exception {
Score expectedScore = new Score(1l, "name", 1, Result.WIN, null);
String jsonScore = "{ "id": 1, "name": "name", "round" : 1, "result" : "WIN", "timestamp": null  }";
when(scoreService.save(expectedScore)).thenReturn(expectedScore);
var ret = scoreService.save(expectedScore); //  mock return correctly
mockMvc.perform( post(ScoreBoardController.REQUEST_URL+ScoreBoardController.POST_REQUEST)
.content(jsonScore)
.contentType(MediaType.APPLICATION_JSON)
.accept(MediaType.APPLICATION_JSON))
.andExpect(status().isOk())
.andExpect(MockMvcResultMatchers.jsonPath("$.id").exists())
.andExpect(MockMvcResultMatchers.jsonPath("$.id").value(1l))
.andExpect(MockMvcResultMatchers.jsonPath("$.name").value("name"))
.andExpect(MockMvcResultMatchers.jsonPath("$.result").value("WIN"));
}
}

在上面的测试中，当我执行post请求scoreService.save(score)在控制器代码中返回null而不是mock分数。为什么?怎么了?

Answer 1

模拟返回null意味着传递给save()的值不等于期望值。这就是我要尝试的:

1. Score执行equals()正确吗?
2. 试试when(scoreService.save(any())).thenReturn(expectedScore)。不管参数是什么，这应该总是返回expectedScore。
3. 试着调试它并检查通过的分数实际上是什么样子的。