/**
* Tests the setError() method.
*
* @covers ::setError
*/
public function testSetError()
{
$form_state = new FormState();
$element['#parents'] = array('foo', 'bar');
$form_state->setError($element, 'Fail');
$this->assertSame(['foo][bar' => 'Fail'], $form_state->getErrors());
}