Espresso utils for TextInputLayout

EspressoTextInputLayoutUtils.java

class EspressoTextInputLayoutUtils{
  /*
   * Use this method to find the EditText within the TextInputLayout. Useful for typing into the TextInputLayout
   */
  public static ViewInteraction onEditTextWithinTilWithId(@IdRes int textInputLayoutId) {
    //Note, if you have specified an ID for the EditText that you place inside
    //the TextInputLayout, use that instead - i.e, onView(withId(R.id.my_edit_text));
    return onView(allOf(isDescendantOfA(withId(textInputLayoutId)), isAssignableFrom(EditText.class)));
  }
  
  /*
   * Use this method to find the error view within the TextInputLayout. Useful for asseting that certain errors are displayed to the user
   */
  public static ViewInteraction onErrorViewWithinTilWithId(@IdRes int textInputLayoutId) {
    return onView(allOf(isDescendantOfA(withId(textInputLayoutId)), not(isAssignableFrom(EditText.class)), isAssignableFrom(TextView.class)));
  }
  
  //Example usage
  @Test
  public void testUsernameTooShortShowsError(){
    onEditTextWithinTilWithId(R.id.tilUsername).perform(typeText("user123"), closeSoftKeyboard()); 
    onView(withId(R.id.sign_up)).perform(click());//Assume there is a button that you click
    onErrorViewWithinTilWithId(R.id.tilUsername).check(matches(withText("Username too short")));
  }
}