如何在单元测试中模拟REST API？

Question

我正在使用RestTemplate exchange HttpMethod.POST方法发布到端点。在我的测试文件中，我正在测试successPOST方法。但是用我目前的测试，我得到了401 Unauthorized errorPOST请求。在测试文件中发出POST请求时，我需要模拟API的帮助

这是我的主文件

@Component
public class DataTestRepo {

    private final RestTemplate restTemplate;
    private final String url;
    private final AllBuilder headersBuilder;

    public DataTestRepo(
            @Qualifier(Oauth.BEAN_NAME) AllBuilder headersBuilder,
            RestTemplate restTemplate, String url) {
        this.headersBuilder = headersBuilder;
        this.restTemplate = restTemplate;
        this.url = url;
    }
    public ResponseEntity<String> postJson(Set<String> results) {
        ResponseEntity<String> result = null;

        try {
            JSONObject jsonObject = new JSONObject(body);

            HttpEntity<String> request = new HttpEntity<String>(jsonObject.toString(), null);
            restTemplate.getMessageConverters().add(stringConvertor);
            result = restTemplate.exchange(url, HttpMethod.POST,
                    new HttpEntity<>(request, getHttpHeaders()), String.class);
         } 
        return result;
    }
}

这是我的测试文件

@RunWith(MockitoJUnitRunner.class)
@TestPropertySource
public class DataTestRepoTest {

    private static final String url = "http://localhost:8080/data/name";

    @Mock
    private DataTestRepo DataTestRepo;
    RestTemplate restTemplate = new RestTemplate();

    @Test
    public void restTemplateHttpPost_success() throws URISyntaxException {
        URI uri = new URI(url);
        Set<String> mockData = Stream.of("A","B").collect(Collectors.toSet());
        Map<String, String> body = new HashMap<>();
        body.put("Name", "Aws");
        JSONObject jsonObject = new JSONObject(body);

        HttpEntity<String> request = new HttpEntity<>(jsonObject.toString(), null);

        ResponseEntity<String> result = restTemplate.exchange(uri, HttpMethod.POST,
                new HttpEntity<>(request, DataTestRepo.getHttpHeaders()), String.class);

        Assert.assertEquals(201, result.getStatusCodeValue());
    }
}

Answer 1

您正在测试DataTestRepo类内部的逻辑，因此您不应模拟它。RestTemplate是DataTestRepo内部的一个依赖项，因此这正是您需要模拟的。通常，它在测试中应如下所示：

@InjectMocks
private DataTestRepo DataTestRepo;
@Mock
RestTemplate restTemplate;

同样，您将必须为模拟的依赖项提供一个返回值，如下所示：

Mockito.when(restTemplate.exchange(ArgumentMatchers.any(), ArgumentMatchers.any(), ArgumentMatchers.any(), ArgumentMatchers.any())).thenReturn(new ResponseEntity<>(yourExpectedDataHere, HttpStatus.OK));
enter code here

这只是一个简单的例子。一个好的做法是检查传递给您的模拟的参数是否等于期望的参数。一种方法是将ArgumentMatchers.any（）替换为实际的预期数据。另一个是单独验证它，如下所示：

Mockito.verify(restTemplate, Mockito.times(1)).exchange(ArgumentsMatchers.eq(yourExpectedDataHere), ArgumentsMatchers.eq(yourExpectedDataHere), ArgumentsMatchers.eq(yourExpectedDataHere), ArgumentsMatchers.eq(yourExpectedDataHere));