Robolectric vs Mockito

We need to understand that Roboelectric and Mockito are two different tools commonly used in android Test Driven Development. So mostly you will find both of the tools in a same project.

Mockito is used for mocking the dependency which means if you want to access an real object in test environment then you need to fake it or we can say mock it. Now a days it is very easier to do mocking of the objects with Mockito.

Roboelectric is the industry-standard unit testing framework for Android. With Robolectric, your tests run in a simulated Android environment inside a JVM, without the overhead of an emulator.

Sample testcase using Roboelectric

@RunWith(AndroidJUnit4.class)
public class MyActivityTest {
@Test
public void clickingButton_shouldChangeResultsViewText() throws Exception {
Activity activity = Robolectric.setupActivity(MyActivity.class);

Button button = (Button) activity.findViewById(R.id.press_me_button);
TextView results = (TextView) activity.findViewById(R.id.results_text_view);

button.performClick();
assertThat(results.getText().toString(), equalTo("Testing Android Rocks!"));
}
}