ServiceResponse mocked which gives a null value and not expected this null - spring-boot

Question

I'm writing j-unit Test-cases for my services and in which i couldn't mock service Response properly, Which is giving me a null. can somebody help me in this issue.
public ResponseEntity<Void> lockGet(
#ApiParam(value = "Unique identifier for this request.", required = true) #RequestHeader(value = "service-id", required = true) String serviceId,
#ApiParam(value = "Logged in userid.", required = true) #RequestHeader(value = "user-id", required = true) String userId,
#ApiParam(value = "Unique messageid.", required = true) #RequestHeader(value = "message-id", required = true) String messageId,
#RequestHeader(value = "access-token", required = true) String accessToken,
#ApiParam(value = "Unique id of the doamin of the entity", required = true) #RequestParam(value = "lockDomainId", required = true) Long lockDomainId,
#ApiParam(value = "Unique id of the entity to be fetched", required = true) #RequestParam(value = "lockEntityId", required = true) Long lockEntityId,
HttpServletRequest request, HttpServletResponse response) {
ResponseEntity<Void> result = null;
if (request.getAttribute("user-id") != null)
userId = (String) request.getAttribute("user-id");
String logContext = "||" + lockDomainId + "|" + lockEntityId + "||";
ThreadContext.put("context", logContext);
long t1 = System.currentTimeMillis();
LOG.info("Method Entry: lockGet" + logContext);
ServiceRequest serviceRequest = AppUtils.mapGetRequestHeaderToServiceRequest(serviceId, userId, lockDomainId,
lockEntityId);
try {
ServiceResponse serviceResponse = lockService.getLock(serviceRequest);
// set all the response headers got from serviceResponse
HeaderUtils.setResponseHeaders(serviceResponse.getResponseHeaders(), response);
result = new ResponseEntity<Void>(HeaderUtils.getHttpStatus(serviceResponse));
} catch (Exception ex) {
LOG.error("Error in lockGet", ex);
result = new ResponseEntity<Void>(HttpStatus.INTERNAL_SERVER_ERROR);
}
ThreadContext.put("responseTime", String.valueOf(System.currentTimeMillis() - t1));
LOG.info("Method Exit: lockGet");
return result;
}
#Test
public void testLockGetForError() {
request.setAttribute("user-id","TestUser");
ServiceRequest serviceRequest = new ServiceRequest();
serviceRequest.setUserId("TestUser");
ServiceResponse serviceResponse = new ServiceResponse();
LockService service = Mockito.mock(LockService.class);
when(service.getLock(serviceRequest)).thenReturn(serviceResponse);
// ServiceResponse serviceResponse = lockService.getLock(serviceRequest);
ResponseEntity<Void> result = new ResponseEntity<Void>(HeaderUtils.getHttpStatus(serviceResponse));
ResponseEntity<Void> lockGet = lockApiController.lockGet("1234", "TestUser", "TestMessage", "TestTkn", 12345L, 12345L, request, response);
assertEquals(HttpStatus.INTERNAL_SERVER_ERROR, lockGet.getStatusCode());
}
I tried in different scenario's which couldn't fix this issue. Can someone help me out. Thanks in advance.

Answer 1

From the code that you have put , the issue that i see is that you are actually mocking the LockService object but when calling the lockApiController.lockGet method the code is not actually working with the mocked LockService since lockApiController has an LockService object of it's own.
One way to solve this issue is to inject the mocked LockService
object into the lockApiController object using #Spy. This way
when the getLock() is called it will be actually called on the
mocked object and will return the mock response provided.
So in your test :
#Test
public void testLockGetForError() {
LockService service = Mockito.mock(LockService.class);
LockApiController lockApiController = Mockito.spy(new LockApiController(service));
request.setAttribute("user-id","TestUser");
ServiceRequest serviceRequest = new ServiceRequest();
serviceRequest.setUserId("TestUser");
ServiceResponse serviceResponse = new ServiceResponse();
when(service.getLock(serviceRequest)).thenReturn(serviceResponse);
// ServiceResponse serviceResponse = lockService.getLock(serviceRequest);
ResponseEntity<Void> result = new ResponseEntity<Void>(HeaderUtils.getHttpStatus(serviceResponse));
ResponseEntity<Void> lockGet = lockApiController.lockGet("1234", "TestUser", "TestMessage", "TestTkn", 12345L, 12345L, request, response);
assertEquals(HttpStatus.INTERNAL_SERVER_ERROR, lockGet.getStatusCode());
}
So you can try passing the mocked LockService object to the spy object.
Another way is to try using the #InjectMocks to inject the mocked
object into the LockApiController.
#InjectMocks marks a field on which injection should be performed. Mockito will try to inject mocks only either by constructor injection, setter injection, or property injection – in this order. If any of the given injection strategy fail, then Mockito won’t report failure.
For example:
#Mock
Map<String, String> wordMap;
#InjectMocks
MyDictionary dic = new MyDictionary();
#Test
public void whenUseInjectMocksAnnotation_thenCorrect() {
Mockito.when(wordMap.get("aWord")).thenReturn("aMeaning");
assertEquals("aMeaning", dic.getMeaning("aWord"));
}
For the class:
public class MyDictionary {
Map<String, String> wordMap;
public MyDictionary() {
wordMap = new HashMap<String, String>();
}
public void add(final String word, final String meaning) {
wordMap.put(word, meaning);
}
public String getMeaning(final String word) {
return wordMap.get(word);
}
}
For both of these to work , you must be having a constructor or appropriate setters to set the mock object to the LockApiController class.
Reference : https://howtodoinjava.com/mockito/mockito-annotations/