[FIXED] Assert null is not working as actual method changes the value

Issue

I am trying to write a Junit for a piece of code for asserting the value as null. But the value is changing on the actual call.

Main Class Code

 @Activate
    public void activate(ComponentContext context)
    {
        myNotificationSubscriber = NotificationSubscriber.newInstance(myGlobalTableNotificationService,
                NotificationType.ENTITIES,
                this);

        setWantedSubscriptionStatus();

        LOG.debug("Activating {} service", getClass().getName());
        try
        {
            applyConfigUpdate(context, IS_ACTIVATION);
        }
        catch (ServiceNotAvailableException e)
        {
            String instanceNameWithException = COUNTER_INSTANCE_COBA.concat("-")
                    .concat(String.valueOf(e.getResponseCode().getResponseCode()))
                    .concat(e.getClass().getSimpleName());
            myCounterregistrator.get()
                    .incrementCounter(Counter.DATAACCESS_COBA_RESPONSE_UNSUCCESSFUL.getCounterInstance(instanceNameWithException));
            LOG.debug("Can not activate Component :{}", e.getMessage());
        }
        LOG.info("COBA Cache state is {}", myCacheState);
    }



  private GlobalTableRetriever getGlobalTableRetrieverer() throws ServiceNotAvailableException
    {
        GlobalTableRetriever tableFetcher = myGlobalTableRetriever.get();
        if (tableFetcher == null)
        {
            throw new ServiceNotAvailableException(RETRIEVER_SERVICE_NOT_AVAILABLE_MSG, ResponseCode.COBA_READ_DATA_TEMPORARY_ERROR);
        }
        return tableFetcher;
    }

I want to write the test for the catch block. So tried to write the test case in below.

 @Test
    public void testapplyConfigUpdate() throws GlobalTableException
    {
        exception.expect(ServiceNotAvailableException.class);
        globalTableRetriever.set(null);
        tableFetcher = globalTableRetriever.get();
        assertThat(tableFetcher).isNull();
        myTableHandler.activate(myOsgiComponentContext);
        verify(myCounterRegistratorService, times(1)).incrementCounter(any(CounterInstance.class));
    }

But once its entering to getGlobalTableRetrieverer method, the assertion null value is changing to original.

Solution

Why do you even need to assert that?

        exception.expect(ServiceNotAvailableException.class);

already implies that tableFetcher is null.

Just try this :

@Test
public void testapplyConfigUpdate() throws GlobalTableException
{
    exception.expect(ServiceNotAvailableException.class);
    globalTableRetriever.set(null);
    tableFetcher = globalTableRetriever.get();
}

Answered By - Sanket Patel