Unit testing a broadcast receiver?

Question

Here's a BroadcastReceiver from my project, which I'm looking to unit test. When the user makes a phone call, it grabs the phone number, and sets up an intent to start a new activity, passing in the phone number.

public class OutgoingCallReceiver extends BroadcastReceiver 
{
    @Override
    public void onReceive(Context xiContext, Intent xiIntent) 
    {
        if (xiIntent.getAction().equalsIgnoreCase(Intent.ACTION_NEW_OUTGOING_CALL))
        {
            String phoneNum = xiIntent.getStringExtra(Intent.EXTRA_PHONE_NUMBER);

            Intent intent = new Intent(xiContext, MyActivity.class);
            intent.putExtra("phoneNum", phoneNum);
            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

            xiContext.startActivity(intent);
            setResultData(null);
        }
    }
}

So far, my unit test looks like this:

public class OutgoingCallReceiverTest extends AndroidTestCase
{
    private OutgoingCallReceiver mReceiver;

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

        mReceiver = new OutgoingCallReceiver();
    }

    public void testStartActivity()
    {
        Intent intent = new Intent(Intent.ACTION_NEW_OUTGOING_CALL);
        intent.putExtra(Intent.EXTRA_PHONE_NUMBER, "01234567890");

        mReceiver.onReceive(getContext(), intent);        
    }
}

This runs through the code, but I want my test to be able to check that the intent was sent out, and to check the phone number on it. How do I do this?

Can I also test that the phone call gets cancelled (because of the setResultData(null) line)?

Answer 1

Matt,

Sounds like you need to mock-up a Context ... and then swap your methods over to accepting interfaces instead of concrete classes: public void onReceive(IContext c, IIntent i), just for the purposes of testing. But then the Context and Intent classes aren't yours are they... they're Android's... so you can't "just" make them implement your interfaces, so you'd have to "wrap" them in order to expose a your interface, which is RATHER a lot of code for not much gain. Very Yucky!!!

So I started to wonder if someone's been through all this before, and done the hard-yards for us... and tada: http://developer.android.com/reference/android/test/mock/package-summary.html

Cheers. Keith.

Answer 2

corlettk pointed me at the MockContext object in Android, which does the trick. I've made a subclass of it, TestContext, which looks like this:

public class TestContext extends MockContext
{
    private List<Intent> mReceivedIntents = new ArrayList<Intent>();

    @Override
    public String getPackageName()
    {
        return "com.mypackage.test";
    }

    @Override
    public void startActivity(Intent xiIntent)
    {
        mReceivedIntents.add(xiIntent);
    }

    public List<Intent> getReceivedIntents()
    {
        return mReceivedIntents;
    }
}

And my test case now looks like this:

public class OutgoingCallReceiverTest extends AndroidTestCase
{
    private OutgoingCallReceiver mReceiver;
    private TestContext mContext;

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

        mReceiver = new OutgoingCallReceiver();
        mContext = new TestContext();
    }

    public void testStartActivity()
    {
        Intent intent = new Intent(Intent.ACTION_NEW_OUTGOING_CALL);
        intent.putExtra(Intent.EXTRA_PHONE_NUMBER, "01234567890");

        mReceiver.onReceive(mContext, intent);        
        assertEquals(1, mContext.getReceivedIntents().size());
        assertNull(mReceiver.getResultData());

        Intent receivedIntent = mContext.getReceivedIntents().get(0);
        assertNull(receivedIntent.getAction());
        assertEquals("01234567890", receivedIntent.getStringExtra("phoneNum"));
        assertTrue((receivedIntent.getFlags() & Intent.FLAG_ACTIVITY_NEW_TASK) != 0);
    }
}

Answer 3

Since this question was asked mocking Frameworks have evolved pretty much. With mockito you can now mock not only interfaces but as well classes. So I would suggest to solve this problem by mocking a context and using ArgumentCapture:

import static org.mockito.Mockito.*;

public class OutgoingCallReceiverTest extends AndroidTestCase {
    private OutgoingCallReceiver mReceiver;
    private Context mContext;

    @Override
    protected void setUp() throws Exception {
        super.setUp();
        //To make mockito work
        System.setProperty("dexmaker.dexcache", 
                mContext.getCacheDir().toString());

        mReceiver = new OutgoingCallReceiver();
        mContext = mock(Context.class);
    }

    public void testStartActivity() {
        Intent intent = new Intent(Intent.ACTION_NEW_OUTGOING_CALL);
        intent.putExtra(Intent.EXTRA_PHONE_NUMBER, "01234567890");

        mReceiver.onReceive(mContext, intent);
        assertNull(mReceiver.getResultData());

        ArgumentCaptor<Intent> argument = ArgumentCaptor.forClass(Intent.class);
        verify(mContext, times(1)).startActivity(argument.capture());

        Intent receivedIntent = argument.getValue();         
        assertNull(receivedIntent.getAction());
        assertEquals("01234567890", receivedIntent.getStringExtra("phoneNum"));
        assertTrue((receivedIntent.getFlags() & Intent.FLAG_ACTIVITY_NEW_TASK) != 0);
    }
}