testFocusInputField() {
    const input = document.getElementById('myInput');
    assertNotEquals(
        'Input should not be focused initially', input, document.activeElement);

    focus.focusInputField(input);
    if (BrowserFeature.HAS_ACTIVE_ELEMENT) {
      assertEquals(
          'Input should be focused after call to focusInputField', input,
          document.activeElement);
    }
    assertEquals(
        'Selection should start at the end of the input text',
        input.value.length, selection.getStart(input));
    assertEquals(
        'Selection should end at the end of the input text', input.value.length,
        selection.getEnd(input));
  }
Tests that focusInputField() puts focus in the input field and sets the
cursor to the end of the text cointained inside.
@suppress {strictMissingProperties} suppression added to enable type
checking