How to close or restart a test instance in an Android InstrumentationTestCase?

Issue

I run my Android tests by running a test implementation which "derives" from a library project (because I have a multi module project with baselib and "concrete app projects"). The test implementation is one of these concrete app projects and is launched by an InstrumentationTestCase. In this test case I mock several parts from the library project by RoboGuice. That means I run a "real" implementation of my baselib with mocked classes (like persistence handling, database handling and so on). To be able to do that, every single test case has to close and restart the whole test instance, because I can't start the same app twice on the device. These test are more integration tests than Junit tests, because I test some kind of workflows, but there is no other possibility to test that, because the possibilities with JUnit on Android testing seem to be very limited. At the moment I can only run one test case at the same time, because if I run more than 1, the whole test is hanging. I already checked if it's the configuration change (see private method) which causes my test to freeze, but this is not the cause. See my attempts in tearDown method. I can't run

getInstrumentation().finish(0, new Bundle());

because I get

Test failed to run to completion. Reason: 'Test run failed to complete. Expected 3 tests, received 1'

I also cannot run

getInstrumentation().callActivityOnDestroy(activity);

because I don't have an Activity here. Moreover the Activity "StartTestActivity" which is launched at startup is not the same Activity which runs when the test is finished because StartTestActivity launches another Activity "MainMenuActivity" which is running at the end of the test. I already thought about using Instrumentation.ActivityMonitor but this doesn't provide the needed functionality.
Nevertheless I want to somehow start with the same test conditions at every test case as the whole test itself does at startup, but I'm not sure what InstrumentationTestCase is doing in the background, so I don't know how to restart the whole instrumentation setup. I somehow need to stop and restart the test instance, or maybe there is a better solution? Any ideas? (by the way: every test itself runs fine, so it's no problem of the test ifself).

public class WorkflowModule1Test extends InstrumentationTestCase
{
    private PersistenceManagerMock persistenceManager;

    @Override
    protected void setUp() throws Exception
    {
        super.setUp();
    }

    @Override
    protected void tearDown() throws Exception
    {
        super.tearDown();

        if (persistenceManager != null)
        {
            persistenceManager.clear();
        }
    }

    public void testSaveLocaleEN() throws PersistenceException
    {
        updateLocaleConfiguration(Locale.ENGLISH);

        Intent intent = new Intent(getInstrumentation().getContext(), StartTestActivity.class);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        getInstrumentation().startActivitySync(intent);

        persistenceManager = (PersistenceManagerMock)RoboGuice.getInjector(ContextProvider.getApplication()).getInstance(IPersistenceManager.class);

        List<Entity> entities = persistenceManager.getEntities();

        assertTrue(entities.size() == 1);
        assertTrue(entities.get(0) instanceof LanguageUsageRel);
        assertTrue(((LanguageUsageRel)entities.get(0)).getLanguageId().equals("EN"));
    }

    public void testSaveLocaleDE() throws PersistenceException
    {
        updateLocaleConfiguration(Locale.GERMAN);

        Intent intent = new Intent(getInstrumentation().getContext(), StartTestActivity.class);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); 
        getInstrumentation().startActivitySync(intent);

        persistenceManager = (PersistenceManagerMock)RoboGuice.getInjector(ContextProvider.getApplication()).getInstance(IPersistenceManager.class);

        List<Entity> entities = persistenceManager.getEntities();

        assertTrue(entities.size() == 1);
        assertTrue(entities.get(0) instanceof LanguageUsageRel);
        assertTrue(((LanguageUsageRel)entities.get(0)).getLanguageId().equals("DE"));
    }

    private void updateLocaleConfiguration(Locale locale)
    {
        Locale.setDefault(locale);
        Configuration configuration = new Configuration();
        configuration.locale = locale;
        getInstrumentation().getContext().getResources().updateConfiguration(configuration, getInstrumentation().getContext().getResources().getDisplayMetrics());
    }
}

Solution

I found the solution on my own. I have to set these two flags.

intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

Answered By - Bevor