Android unit testing with Robolectric - Simple examples

Here are some simple examples to learn unit testing android code using robolectric quickly.

Robolectric examples :

• Testing setContentView

• Testing start of an activity

• Testing send SMS (SMS Manager)

• Testing request location updates (Location Manager)

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

Android - Robolectric - Unit testing start of an activity

Here is the android code to start an activity on click of a button

Android Code to test :

	public class MainActivity extends Activity {
	@Override
	protected void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	setContentView(R.layout.main_layout);
	}
	public void onButtonClick(View v) {
	startActivity(new Intent(this, SecondActivity.class));
	}
	}

view raw MainActivity.java hosted with ❤ by GitHub

To test the above code,
1) First, You can call button's performClick to simulate a click event
2) Now, Get the shadowActivity using the robolectric's shadowOf method
3) This shadow Object has all the methods to test an activity
4) We can get the next started activity's Intent, using the getNextStartedActivity() method and assert it

Robolectric Test :

	@RunWith(RobolectricTestRunner.class)
	public class MainActivityTest {
	private MainActivity mainActivity;
	private Button button;
	@Before
	public void setUp() {
	mainActivity = new MainActivity();
	mainActivity.onCreate(null);
	button = (Button) mainActivity.findViewById(R.id.open_button);
	}
	@Test
	public void shouldStartTheSecondActivityOnButtonClick() throws Exception {
	ShadowActivity shadowActivity = shadowOf(mainActivity);
	button.performClick();
	Intent startedIntent = shadowActivity.getNextStartedActivity();
	assertThat(startedIntent.getComponent().getClassName(),
	equalTo(SecondActivity.class.getName()));
	}
	}

view raw MainActivityTest.java hosted with ❤ by GitHub

Android - Robolectric- Unit testing send SMS

Sending SMS in android is so simple, you just have to get the default SMSManager and call the sendTextMessage

Android Code :

	public void sendSMS(String phoneNumber, String message) {
	SmsManager smsManager = SmsManager.getDefault();
	smsManager.sendTextMessage(phoneNumber, null, message, null, null);
	}

view raw sendSMS.java hosted with ❤ by GitHub

Testing the above code is even simpler,
1) Get the shadowSMSManager
2) From it, we can get the lastSentTextMessageParams, which has the details abt the last sent SMS.
3) Assert with the expected values

Robolectric Test :

	@Test
	public void shouldSendSMSToTheGivenPhoneNumber() {
	String message = "Android is cool";
	String phoneNumber = "123-123-1222";
	smsTestActivity.sendSMS(phoneNumber, message);
	ShadowSmsManager shadowSmsManager = shadowOf(SmsManager.getDefault());
	ShadowSmsManager.TextSmsParams lastSentTextMessageParams = shadowSmsManager.getLastSentTextMessageParams();
	assertEquals(phoneNumber, lastSentTextMessageParams.getDestinationAddress());
	assertEquals(message, lastSentTextMessageParams.getText());
	}

view raw SMSTestActivityTest.java hosted with ❤ by GitHub

Android - Robolectric - Unit testing setContentView

Normally the first thing we do in an Activity is to set the content view to a layout xml.
For example consider the below TestActivity, onCreate it sets its contentView to test_layout.xml

	public class TestActivity extends Activity {
	@Override
	public void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	setContentView(R.layout.test_layout);
	}
	}

view raw TestActivity.java hosted with ❤ by GitHub

And the test_layout.xml is (Note : id of the root element android:id="@+id/test_layout_root")

	<?xml version="1.0" encoding="utf-8"?>
	<TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:id="@+id/test_layout_root"
	android:layout_height="match_parent"
	android:layout_width="wrap_content"
	...
	...
	</TableLayout>

view raw TestLayout.xml hosted with ❤ by GitHub

In the robolectric test, we need to get the activity's content view id and assert it with the layout id

	@RunWith(RobolectricTestRunner.class)
	public class TestActivityTest {
	private TestActivity testActivity;
	@Before
	public void setup() {
	testActivity = new TestActivity();
	testActivity.onCreate(null);
	}
	@Test
	public void shouldSetTheTestLayoutOnCreate() {
	assertEquals(R.id.test_layout_root, shadowOf(testActivity).getContentView().getId());
	}
	}

view raw TestActivityTest.java hosted with ❤ by GitHub