用于Void返回类型的方法的Junit测试用例

Question

I am new in writing the junit test cases and need help. I read about possible solutions but they are not working at this point.

Main class looks like below, which calls the method of ther class addResponseData(This method only sets values in session and returns nothing). Please see the code as per below.

@Test
public void testPublishData_Success() throws java.lang.Exception {
    when(GetPropValues.getPropValue(PublisherConstants.ATMID)).thenReturn("ATM");
    when(GetPropValues.getPropValue(PublisherConstants.DATA_SOURCE)).thenReturn("PCE");

    ReadAndWriteFiles mockFiles = Mockito.mock(ReadAndWriteFiles.class);
    PowerMockito.whenNew(ReadAndWriteFiles.class).withNoArguments().thenReturn(mockFiles);
    Mockito.when(mockFiles.getAllFiles()).thenReturn(null);

    KafkaProducer mockProducer = Mockito.mock(KafkaProducer.class);
    PowerMockito.whenNew(ReadAndWriteFiles.class).withAnyArguments().thenReturn(mockProducer);

    producer.publishData(null, "Test", "Data1");
}

    ResponseWrapper signerResponse;
    try {
        privateClassObj.ensureDataLoaded(objSession); // Loads the required data into objSession)

        signerResponse = new ResponseWrapper(ResponseType.SUCCESS);
        signerResponse.addResponseData("signerList", objSession.getSignerList());
        signerResponse.addResponseData("additionalSignerList", objSession.getAdditionalSignerList());
    }
    catch (ServiceException err) {
        signerResponse = new ResponseWrapper(ResponseType.PARTIAL_SUCCESS);
    }

    return signerResponse;
}

TestClass: I have written junit test case as per below.

    @Test
public void testSuccessfulCallWithSigners() {
    List<Signer> signerList = setSignerList();
    List<Signer> additionalSignerList = setSignerList();
    when(objSession.getSignerList()).thenReturn(signerList);
    when(nsbSession.getAdditionalSignerList()).thenReturn(additionalSignerList);
    ResponseWrapper output = signerController.getUsers(request); // actual method call
    assertEquals(output, responseWrapper);
}

This test case is failing because, I always get empty signerList and additionalSignerList.(test case result is getAdditionalSignerList() method should return List) Please let me know what am I doing wrong here. Thanks in Advance. I am also posting my the code of setSignerList() in case if you want to see it for reference.

private List<Signer> setSignerList() {
    List<Signer> signerList = new ArrayList<Signer>();
    signerList.add(primarySigner); // primarySigner is mock object.
    return signerList;
}

Answer 1

You have mocked objSession and also you have returned your empty list when these two methods get called by the test case.

when(....).thenReturn(....) is used to specify a condition and a return value (Stubbing) for this condition.As you have mocked it and return your desired list using stubbing, it will not return the list returned by actual call.

List<Signer> signerList = setSignerList(); // EMPTY LIST
List<Signer> additionalSignerList = setSignerList(); // EMPTY LIST
when(objSession.getSignerList()).thenReturn(signerList); //MOCK
when(nsbSession.getAdditionalSignerList()).thenReturn(additionalSignerList); // MOCK