How to unit test a service which sets attribute to newly created object - spring

I want to write unit test for one of my service to verify certain fields get assigned.
public void createNewRecord(Dto dto) {
Record record = new Record();
record.setName(dto.getName());
record.setDetail(dto.getDetail());
repo.save(record);
}
I don't have a constructor for dto because a record has many attributes and some of them get assigned from other methods. My previous plan is: mock the record and verify setName() and setDetail methods are called once. But there is no way to inject mocked record into this service. Do I have to change my previous code? Any thought is appreciated.

There are several approaches:
First:
change method to this
public void createNewRecord(Record record, Dao dao)
Second:
Use PowerMockito to mock constructor
Third:
Use factory or com.google.inject.Provider for construct record (I prefer this)
Forth:
If record constructor is simple and setters for record also don't have some special logic then you can mock only repo and verify repo's argument.

Mocks should be used for mocking a dependency of the tested object, not for mocking an inner object in the tested method.
Why don't you mock the repo instance and then you would verify with you mock api that repo.save() is called with the expected record ?
It seems to be a straight way to unit test your method.

You can use Mockito and its #Captor annotation to capture the arguments passed to the repo instance. You can #Mock the Dto object to create expectations for the getName() and getDetail() methods and assert that the results of invoking the setName() and setDetail() methods on the captured Record instance are the same values expected from the Dto object. For example:
#Mock
private Repo repo;
#Mock
private Dto dto;
#Captor
private ArgumentCaptor<Record> recordArgumentCaptor;
private Service service;
#Before
public void setUp() throws Exception {
MockitoAnnotations.initMocks(this);
this.service = new Service(repo);
}
#Test
public void shouldCreateNewRecord() {
when(dto.getName()).thenReturn("NAME");
when(dto.getDetail()).thenReturn("DETAIL");
service.createNewRecord(dto);
verify(repo).save(recordArgumentCaptor.capture());
Record record = recordArgumentCaptor.getValue();
assertThat(record.getName(), is(equalTo(dto.getName())));
assertThat(record.getDetail(), is(equalTo(dto.getDetail())));
}

Related

Can this method be tested using mockito?

I am not sure how to test the first method in the service layer with Mockito as it is using the helper method. Below is my failed attempt at a test: I get an InvalidUseOfMatchersException in the second when clause.
Thanks in advance!
#Mock
private EntityRepository EntityRepo;
#InjectMocks
private EntityService EntityService;
public List<DTO> getAllDTOs(){
//first method
return entityRepo.findAll()
.stream()
.map(this::convertEntityToDTO)
.collect(Collectors.toList());
}
//helper method
public DTO convertEntityToDTO(Entity entity) {
ModelMapper modelMapper = new ModelMapper();
modelMapper.getConfiguration()
.setMatchingStrategy(MatchingStrategies.LOOSE);
DTO dto = new DTO();
dto = modelMapper.map(entity, DTO.class);
return dto;
}
#Test
public void EntityService_GetAll_ReturnsDTOList() {
when(entityRepo.findAll()).thenReturn(Mockito.anyList());
//the second when clause: when(entityService.convertEntityToDTO(Mockito.any(Entity.class)))
.thenReturn(Mockito.any(DTO.class));
List<DTO>DTOList = entityService.getAllDTOs();
Assertions.assertThat(DTOList).isNotNull();
Mockito#any* methods are actually defined in class ArgumentMatchers and can only be used to match the call arguments when setting up a mock or when verifying calls. All matcher methods return null (but have side-effects of modifying a matcher stack to be able to properly detect and match mocked calls).
For instance, you might do Mockito.when(svc.print(Mockito.anyString()).doNothing() when you don't care about the input or Mockito.verify(svc.print(Mockito.anyString()), Mockito.never()) when you want to verify that the method has never been called.
When setting up your mock, you have to provide a real value in your thenReturn call:
when(entityRepo.findAll()).thenReturn(Collections.emptyList());
when(entityService.convertEntityToDTO(Mockito.any(Entity.class)))
.thenReturn(new DTO());

How to mock private method in public method in Spring Boot with JUnit

I'd like you ask a few questions and ask you for advice:
I want to test my public method (I use Spring Boot, Mockito, JUnit):
#Service
public class MyClass{
public Long getClientId(List<String> nameSurname) throws AuthorizationException {
Long operatorId;
if(...){
(... something not interesting ...)
User user = getUserByLogin("AnthonyGates2");
operatorId = nonNull(user) ? user.getOperatorId() : null;
} else {
List<User> users = getUserListByLogin("AnthinyGates");
operatorId = isNotEmpty(users) ? return operatorId;
return operatorId;
}
How to test the method getClientId?
Methods getUserByLogin and getUserListByLogin are private in this class (MyClass) but I have to mock the results of these private methods because these methods retrieve data from an external service.
These private methods looks like:
User user = DelegateImpl.getDelegate().getUserByLogin(nameAndSurname);
DelegateImpl.getDelegate().getUserByLogin get data from database and that data have to be mocked like:
when(DelegateImpl.getDelegate().getUserByLogin(any())).thenReturn(user);
How can I test my public class? Should I use PowerMock/PowerMockito? Making these methods public is in my opinion ugly because these methods are called only in MyClass. I can't find a good tutorial in Internet for my case (Spring Boot, Mockito, JUnit).
Thank you very much for all your tips!
Best regards
Matthew
Test the unit only by calling the public methods. I think that your example is a class in the service layer (contains business logic) and the two getUser... methods should be in a different class (I think in the data layer) where they can be public. Inject that class via the constructor as a dependency (in the service object) so you can mock it when testing the service class. The data layer class (with the getUser... methods) can also be tested by it's own unit tests.
If you are not able to unit test a method/class then it most probably means that it just does too much. Try extracting your private methods to a separate class. It does not need to be public - you can e.g. have it package-local in the same package.
Later, in the test, you would have to inject a mock of this class and simulate its behaviour.
The setup of MyClass in its unit test could look similar to this:
AnotherClass anotherClassMock = Mockito.mock(AnotherClass.class);
MyClass myClass = new MyClass(anotherClassMock);
Where AnotherClass would have methods getUserListByLogin and getUserByLogin.
EDIT:
It seems that the logic within in your private methods already call an external class. The problem is that you obtain an instance of an object via a call to a static getDelegate() method in another class.
Here's what you can do:
Create a new field in MyClass which would have the same type as the one returned by getDelegate() method (I don't know what that is, I'll call it Delegate)
Have 2 constructors: a default one which would assign the result of getDelegate method to your new field and another one which would take an instance of Delegate as a parameter and assign it to your field
In tests use the second constructor to create an instance of MyClass and pass a mock of Delegate class
It would look more ore less like this:
class MyClass() {
private Delegate delegate;
MyClass() {
this.delegate = DelegateImpl.getDelegate();
}
MyClass(Delegate delegate) {
this.delegate = delegate;
}
// ... the rest
}

Unit Test Spring ApplicationEventPublisher

I am trying to write a unit test for the following code:
public void doSomething(List<Object> someObjects){
// Some logic I want to test...
eventPublisher.publishEvent(someEvent);
}
So in the project I call this method that perform some logic to the list of objects, and then as a result it publish the Application event with the result a method that was recieved.
I want to verify the logic inside that method with unit test but I am not sure how I can write the unit test if the method does not return nothing directly but publish a domain event. What is the correct way to do this?
thanks for your help.
As part of unit test, it is enough to verify if the `eventPublisher. is called with the correct argument. And also, remember that unit test is the document for the each every line of code for the method to be tested.
You have to mock the eventPublisher in test and use ArgumentCaptor to capture the argument which is being passed while invoking the message.
Ideally, your test should look like:
public class ClassToBeTestedTest {
#Mock
private ApplicationEventPublisher eventPublisher;
#InjectMocks
private ClassToBeTested classToBeTested;
#Captor
private ArgumentCaptor<SomeClass> captor;
#Before
public void init() {
initMocks(this);
}
#Test
public void testSend() throws Exception {
classToBeTested.doSomething(Arrays.asList());
verify(eventPublisher).publishEvent(captor.capture());
assertThat(captor.getValue(), is("expected value"))
}
}

Why doesn't Mockito's when() get triggered?

I need to test a service class, but when I try to mock the dao class, it doesn't get triggered, thus not able to use ThenReturn().
I think that the problem is because I use an interface for my Dao and #Autowired in the service class (Spring MVC 3.1):
The interface:
public interface TestDao {
int createObject(Test test) throws NamingException;
}
The implementation:
#Repository
public class TestDaoImpl implements TestDao {
#Override
public int createObject(Test test) {
KeyHolder keyHolder = new GeneratedKeyHolder();
jdbcTemplate.update(new InsertNewTest(test), keyHolder);
return ((java.math.BigDecimal)keyHolder.getKey()).intValue();
}
}
The service:
public class RegTest {
#Autowired
TestDao testDao;
public int regTest(int .....) {
.
.
int cabotageId = testDao.createObject(test);
}
}
In the test I have:
#RunWith(MockitoJUnitRunner.class)
public class TestRegService {
#InjectMocks
private RegTest regTest = new RegTest();
#Mock
TestDao testDao;
#Test()
public void test() {
.
when(testDao.createObject(null)).thenReturn(100);
.
}
testDao.createObject(null) returns 0 (due to being mock'ed) and not 100 as I is trying to achieve.
Can anybody help, please?
Problem solved!
It was the passing test-object to createObject() that did not match. Using
testDao.createObject(any(Test.class))
did the trick!
If your test is actually passing a value to createObject, then when(testDao.createObject(null)... never gets matched. Rather than matching on null, you could match any instance of Test with testDao.createObject(any(Test.class))...
Also when you tried later to supply new Test() as the argument to match, it will literally try to match on that exact instance of Test, but presumably your real code is new-ing up a different one. So the use of Matchers.any(Test.class) as the parameter to match is the way to go.
Mockito injection mechanism don't know about Spring #Autowired or CDI #Inject annotations. It just tries to find the best candidate given the type and the name of the mock, and it can lookup private fields too. See the javadoc of #InjectMocks : http://docs.mockito.googlecode.com/hg/1.9.0/org/mockito/InjectMocks.html
The semantic you are using is correct, though if you are experiencing issues, I would rather look for incorrect interactions or incorrect arguments.
Are you sure the test variable in regTest.regTest(int...) is really null when passed to testDao.createObject(test) ?
I don't know if this is a typo in the example, but you have RegTest.regTest() calling createTest() rather than createObject(). Otherwise, I don't think #Autowired has anything to do with it, since your test itself is not running in a container with Spring management. If it is not a typo, and createTest is in fact a real and different method from createObject, then the default behaviour of a mocked object in Mockito is to return the appropriately-typed zero for numeric return types.
I think that you're right about the autowire not getting called. You could inject the dao yourself using the setTestDao() call instead. Mockito also supports spy which allows you to trace the objects code and just replace functions instead.

Unit testing with Mockito

I am writing unit tests for service layer in my spring application.
Here is my service class
#Service
public class StubRequestService implements RequestService {
#Autowired
private RequestDao requestDao;
#Transactional(propagation = Propagation.REQUIRED, readOnly = true)
#Override
public Request getRequest(Long RequestId) {
Request dataRequest = requestDao.find(requestId);
return dataRequest;
}
}
Here is my test class
#RunWith(MockitoJUnitRunner.class)
#ContextConfiguration(locations = { "/META-INF/spring/applicationContext.xml" })
public class StubRequestServiceTest {
#Mock
public RequestDao requestDao;
StubRequestService stubRequestService; // How can we Autowire this ?
#org.junit.Before
public void init() {
stubRequestService = new StubRequestService(); // to avoid this
stubRequestService.setRequestDao(dataRequestDao);
// Is it necessary to explicitly set all autowired elements ?
// If I comment/remove above setter then I get nullPointerException
}
#Test
public void testGetRequest() {
Request request = new Request();
request.setPatientCnt("3");
when(requestDao.find(anyLong())).thenReturn(request);
assertEquals(stubRequestService.getRequest(1234L).getPatientCnt(),3);
}
}
Its working fine but I have few questions
How can we Autowire service class in test ? I am using constructor in init() method to create service object.
Do we have to set all Autowire element for service class ? For ex StubRequestService have autowired RequestDao which I need to set explicitly before calling test method otherwise it giveds nullPointerException as requestDao is null in StubRequestService.getRequest method.
Which are the good practices to follow while unit testing Spring service layer ? (If I am doing anything wrong).
Your test is fine. It doesn't even have to have the #ContextConfiguration annotation.
The whole point of dependency injection frameworks like Spring is to be able to unit test services by simply instantiating them, setting mock dependencies, and then call their methods.
You're doing it correctly. You don't need to have a Spring context for such unit tests. That's why they're called unit tests: they test it in isolation of all their actual dependencies, Spring included.
Side note: assuming you're using JUnit, the arguments of the assertXxx method should be swapped. The expected value comes before the actual value. It becomes important when the assertion fails and you have a message like "expecting 6 but was 3" rather than "expecting 3 but was 6".
If you really feel that it will make your tests easier to understand - you can initialize a spring context and fetch all of the objects from there. However, usually it will require creating a separate spring configuration XML file specifically for tests therefore I would not recommend it.
ApplicationContext applicationContext = new ClassPathXmlApplicationContext("testApplicationContext.xml");
stubRequestService = (RequestService)applicationContext.getBean("myRequestServiceBean");
(and 3) Basically, I prefer testing each component of my application in total isolation from eachother and that's why I do not recommend what I described in [1].
What that means, is you take a separate logical slice of your application and test only it, while fully mocking up everything it tries to access.
Let's say you have three classes:
//Fetches stuff from some webservice and converts to your app domain POJOs
class DataAccessLayer {
public void setWebservice(Webservice ws) {...};
public MyObject getMyObject() {...};
}
//Formats the domain POJOs and sends them to some kind of outputstream or stuff.
class ViewLayer {
public void setOutputStream(OutputStream os) {...};
public void viewMyObject(MyObject mo) {...};
}
//Main entry point of our MyObject fetch-process-display workflow
class Controller {
public void setDataAccessLayer(DataAccessLayer dal) {...};
public void setViewLayer(ViewLayer vl) {...};
public void showMyObject() {
MyObject mo = dal.getMyObject();
...some processing here maybe...
vl.viewMyObject(mo);
}
}
Now, what tests can we write here?
Test if DataAccessLayer properly converts the object from mocked up WS to our domain object.
Test if ViewLayer properly formats the object given to him and writes it to mocked up output stream.
Test if Controller takes an object from mocked up DataAccessLayer processes it properly and sends it to mocked up ViewLayer.
Or You can use springockito
https://bitbucket.org/kubek2k/springockito/wiki/Home, it will make your tests cleaner

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