Testing Pull Subscription in Java EWS API using PowerMockito

Question

I have a function that processes events obtained by a PullSubscription to Microsoft Exchange.

public void processEvents(ExchangeService service, PullSubscription subscription)
            throws Exception {
    GetEventsResults events = subscription.getEvents();
    // Loop through all item-related events.
    for (ItemEvent itemEvent : events.getItemEvents()) {
        if (itemEvent.getEventType() == EventType.NewMail) {
            EmailMessage message = EmailMessage.bind(service, itemEvent.getItemId());
            EmailParser emailParser = new EmailParser();
            emailParser.parse(message, service);
        }
    }
}

I am trying to test it using PowerMockito because ExchangeService is a final class. So I have mocked ExchangeService and PullSubscription as follows:

ExchangeService serviceMock = PowerMockito.mock(ExchangeService.class);
PullSubscription subscriptionMock = PowerMockito.mock(PullSubscription.class);

@Test
public void startPullNotification() throws Exception {
    ProcessEmails pr = new ProcessEmails("config.properties");
    pr.startPullNotification(serviceMock);
}

When I'm trying to test it using the following code it throws a NullPointerException because subscription.getEvents() returns null (i.e. the subscriptionMock has no events in it).

I tried stubbing it by mocking the eventResults that has to be returned:

when(subscriptionMock.getEvents()).thenReturn(eventResultsMock);

It doesn't work since the getEvents() is not called in the test function. I wanted to know how to test this function?

http://archive.msdn.microsoft.com/ewsjavaapi

Solution:

I had to mock every object being created in the function. Also, I had to add the following above the class declaration.

@RunWith(PowerMockRunner.class)
@PrepareForTest({ ClassBeingTested.class })