Is it possible to verify arbitrary interaction using Mockito in a compact way?

Question

It is easy to verify that specific interaction (specific method call) occurred on a mock object in Mockito, and there is verifyZeroInteractions() for checking that no interactions occurred at all. Suppose I'm testing an interface such as that of a logger, with methods such as info(), warn(), error() etc. In a specific scenario I know one of these methods should be called, but I don't really care which one. Is there a compact way to check that any interaction with the mock object occurred without the need of specifying which exactly method should be called? Or perhaps such a mechanism is not necessary because "the Mockito way" of testing this would be different from what I imagine?

Answer 1

With log4j, to test the logger I do the following setup:

@Mock private Appender log4jAppender;
private Logger logger;

@Before
public void setup() {
    MockitoAnnotations.initMocks(this);

    Logger root = Logger.getRootLogger();
    if (!root.getAllAppenders().hasMoreElements()) {
        // No appenders means log4j is not initialized!
        BasicConfigurator.configure();
    }
    logger = Logger.getLogger(MyClassWhichLogs.class);
    logger.addAppender(log4jAppender);
}

and then in my test I do the following:

verifyZeroInteractions(log4jAppender);

or

verify(log4jAppender).doAppend(any(LoggingEvent.class);

If you need to test the values logged, you can provide a captor instead:

ArgumentCaptor<LoggingEvent> logCaptor = ArgumentCaptor.forClass(LoggingEvent.class);
verify(log4jAppender).doAppend(logCaptor.capture());
assertTrue(logCaptor.getValue().contains("my text to match");

While this doesn't necessarily answer the generalized question (I don't think what you're looking for exists), it may solve this specific problem for testing logging.