How to Mock client side rest service - spring-boot

Question

I'm trying to create mockito test run for rest api below is the controller class followed by mock test which I'm trying to execute but the problem is it is still calling actual rest api instead of mocking it,
1) Controller Class
public void sendData(ID id, String xmlString, Records record) throws ValidationException{
ClientHttpRequestFactory requestFactory = new
HttpComponentsClientHttpRequestFactory(HttpClients.createDefault());
RestTemplate restTemplate = new RestTemplate(requestFactory);
List<HttpMessageConverter<?>> messageConverters = new ArrayList<>();
messageConverters.add(new StringHttpMessageConverter(Charset.forName("UTF-8")));
restTemplate.setMessageConverters(messageConverters);
MultiValueMap<String,String> header = new LinkedMultiValueMap<>();
header.add("x-api-key",api_key);
header.add("Content-Type",content_type);
header.add("Cache-Control",cache_control);
HttpEntity<String> request = new HttpEntity<>(xmlString, header);
try {
restTemplate.postForEntity(getUri(id,record), request, String.class);
}catch (RestClientResponseException e){
throw new ValidationException("Error occurred while sending a file to some server "+e.getResponseBodyAsString());
}
}
2) Test class
#RunWith(MockitoJUnitRunner.class)
public class Safe2RestControllerTest {
private MockRestServiceServer server;
private RestTemplate restTemplate;
private restControllerClass serviceToTest;
#Before
public void init(){
//some code for initialization of the parameters used in controller class
this.server = MockRestServiceServer.bindTo(this.restTemplate).ignoreExpectOrder(true).build();
}
#Test
public void testSendDataToSafe2() throws ValidationException, URISyntaxException {
//some code here when().then()
String responseBody = "{\n" +
" \"responseMessage\": \"Validation succeeded, message
accepted.\",\n" +
" \"responseCode\": \"SUCCESS\",\n" +
" 2\"responseID\": \"627ccf4dcc1a413588e5e2bae7f47e9c::0d86869e-663a-41f0-9f4c-4c7e0b278905\"\n" +
"}";
this.server.expect(MockRestRequestMatchers.requestTo(uri))
.andRespond(MockRestResponseCreators.withSuccess(responseBody,
MediaType.APPLICATION_JSON));
serviceToTest.sendData(id, xmlString, record);
this.server.verify();
}
}
How should I go ahead, any suggestion would be appreciated.

Answer 1

Spring's MVC test apparatus makes this quite easy.
#RunWith(SpringRunner.class)
#WebMvcTest(controllers = YourController.class)
public class YourControllerTest {
#Autowired
private MockMvc mockMvc;
#Test
public void testSendDataToSafe2() throws Exception {
// prepare e.g. create the requestBody
MvcResult mvcResult = mockMvc.perform(post(uri).contentType(MediaType.APPLICATION_JSON).content(requestBody))
.andExpect(status().isOk())
.andReturn();
Assert.assertEquals(responseBody, mvcResult.getResponse().getContentAsString());
}
}
For more details, see the section titled "Add Unit Tests" here and/or the section titled "Auto-configured Spring MVC tests" here.
Your question also states "the problem is it is still calling actual rest api" so I'm guessing that, in addition to calling your controller is a test context, you want that mock out some of the behaviour of that controller. Specifically, you want to mock the RestTemplate instance used in that controller. If so, then would have to change the controller implementation such that the RestTemplate instance is an #Autowired class member. Then you would declare a mock for that in your test case like so:
#RunWith(SpringRunner.class)
#WebMvcTest(controllers = YourController.class)
public class YourControllerTest {
#Autowired
private MockMvc mockMvc;
#MockBean
private RestTemplate restTemplate;
#Test
public void testSendDataToSafe2() throws Exception {
// prepare e.g. create the requestBody
// tell your mocked RestTemplate what to do when it is invoked within the controller
Mockito.when(restTemplate.postForEntity(..., ..., ...)).thenReturn(...);
MvcResult mvcResult = mockMvc.perform(post(uri).contentType(MediaType.APPLICATION_JSON).content(requestBody))
.andExpect(status().isOk())
.andReturn();
Assert.assertEquals(responseBody, mvcResult.getResponse().getContentAsString());
}
}
The above code is valid for spring-test:4.3.10.RELEASE.