用其他方法模拟方法

Question

I have the following method that I want to test:

public boolean sendMessage(Agent destinationAgent, String message, Supervisor s, MessagingSystem msgsys, String time) throws ParseException {
    if(mailbox.getMessages().size() > 25){
        return false;
    }else{
        if(login(s, msgsys, time)){
            try {
                sentMessage = msgsys.sendMessage(sessionkey, this, destinationAgent, message);
                if(sentMessage.equals("OK")) {
                    return true;
                }
                return false;
            } catch (ParseException e) {
                e.printStackTrace();
                return false;
            }
        }
        return false;
    }
}

I want to mock the method login(s, msgsys, time) . I am doing this as follows:

@Mock
private Supervisor supervisor;
@Mock
private MessagingSystem msgsys;

@Test
public void testSendMessageSuccess() throws ParseException {
    String message = "Hey";
    Agent destination = new Agent("Alex", "2");
    agent.sessionkey = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";

    when(agent.login(supervisor, msgsys, anyString())).thenReturn(true);
    when(msgsys.sendMessage(agent.sessionkey, destination, agent, message)).thenReturn("OK");

    boolean result = agent.sendMessage(destination, message, supervisor, msgsys, time);

    assertEquals(true, result);
}

However, the following error is encountered:

org.mockito.exceptions.misusing.WrongTypeOfReturnValue: 
Boolean cannot be returned by getLoginKey()
getLoginKey() should return String

Please do note that the method getLoginKey() - returns a String, is called inside the method login(s, msgsys, time) , and it belongs to an interface class.

@Before
public void setup(){
    MockitoAnnotations.initMocks(this);
    agent = new Agent("David", "1");
    time = dateFormat.format(new Date());
}

@After
public void teardown(){
    agent = null;
}

Answer 1

If you want to mock one of the methods of Agent ( login() in your case) then the Agent you are trying to stub needs to be a mock or a spy.

Since in your case login() is the only method you want to mock with the rest of the functionality of the Agent class intact then you should make a spy of this object:

@Before
public void setup(){
    MockitoAnnotations.initMocks(this);
    agent = Mockito.spy(new Agent("David", "1"));
    time = dateFormat.format(new Date());
}

Note that when stubbing spies to you need to use the following syntax:

doReturn(true).when(agent).login(supervisor, msgsys, anyString());