Android - Robolectric - Unit testing request location updates (LocationManager)

Here is the android code to register for network, GPS and passive location updates on activity create

Android Code to test :

	public class MainActivity extends Activity implements LocationListener {
	private Location latestLocation;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	setContentView(R.layout.main_layout);
	initLocationListener();
	}
	private void initLocationListener() {
	LocationManager locationManager = (LocationManager)
	getSystemService(Context.LOCATION_SERVICE);
	List<String> allProviders = locationManager.getAllProviders();
	for (String provider : allProviders) {
	locationManager.requestLocationUpdates(provider, 0, 0, this);
	}
	}
	@Override
	public void onLocationChanged(Location location) {
	latestLocation = location;
	}
	public Location latestLocation() {
	return latestLocation;
	}
	@Override
	public void onStatusChanged(String s, int i, Bundle bundle) {}
	@Override
	public void onProviderDisabled(String s) {}
	@Override
	public void onProviderEnabled(String s) {}
	}

view raw LocationActivity.java hosted with ❤ by GitHub

To test the above code,
1) First you need to create a mock location
2) Get the ShadowLocationManager using the robolectric's shadowOf method
3) This shadow Object has a method called 'simulateLocation' to mock a location update.
4) Now we can assert the actual value obtained by the listener with the expected value

Robolectric Test :

	@RunWith(RobolectricTestRunner.class)
	public class MainActivityTest {
	private MainActivity mainActivity;
	@Before
	public void setUp() {
	mainActivity = new MainActivity();
	mainActivity.onCreate(null);
	}
	@Test
	public void shouldReturnTheLatestLocation() {
	LocationManager locationManager = (LocationManager)
	Robolectric.application.getSystemService(Context.LOCATION_SERVICE);
	ShadowLocationManager shadowLocationManager = shadowOf(locationManager);
	Location expectedLocation = location(NETWORK_PROVIDER, 12.0, 20.0);
	shadowLocationManager.simulateLocation(expectedLocation);
	Location actualLocation = mainActivity.latestLocation();
	assertEquals(expectedLocation, actualLocation);
	}
	private Location location(String provider, double latitude, double longitude) {
	Location location = new Location(provider);
	location.setLatitude(latitude);
	location.setLongitude(longitude);
	location.setTime(System.currentTimeMillis());
	return location;
	}
	}

view raw LocationActivityTest.java hosted with ❤ by GitHub