espresso.java

private MainActivity activity;

@Before
public void setup() {
  activity = Robolectric.buildActivity(MainActivity.class).get();
}

@Test
public void shouldProduceGreetingWhenButtonPressed() {
  TextView textView = (TextView) activity.findViewById(R.id.textView);
  Button button = (Button) activity.findViewById(R.id.button);
  EditText editText = (EditText) activity.findViewById(R.id.editText);

  editText.setText("Bruno");
  button.performClick();

  assertThat(textView).containsText("Hello, Bruno!");
}