class FormValuesTest

class FormValuesTest extends WebDriverTestBase {
  
  /**
   * {@inheritdoc}
   */
  protected static $modules = [
    'node',
    'ajax_test',
    'ajax_forms_test',
  ];
  
  /**
   * {@inheritdoc}
   */
  protected $defaultTheme = 'stark';
  
  /**
   * {@inheritdoc}
   */
  protected function setUp() : void {
    parent::setUp();
    $this->drupalLogin($this->drupalCreateUser([
      'access content',
    ]));
  }
  
  /**
   * Submits forms with select and checkbox elements via Ajax.
   */
  public function testSimpleAjaxFormValue() {
    $this->drupalGet('ajax_forms_test_get_form');
    $session = $this->getSession();
    $assertSession = $this->assertSession();
    // Verify form values of a select element.
    foreach ([
      'green',
      'blue',
      'red',
    ] as $item) {
      // Updating the field will trigger an AJAX request/response.
      $session->getPage()
        ->selectFieldOption('select', $item);
      // The AJAX command in the response will update the DOM
      $select = $assertSession->waitForElement('css', "div#ajax_selected_color:contains('{$item}')");
      $this->assertNotNull($select, "DataCommand has updated the page with a value of {$item}.");
    }
    // Verify form values of a checkbox element.
    $session->getPage()
      ->checkField('checkbox');
    $div0 = $this->assertSession()
      ->waitForElement('css', "div#ajax_checkbox_value:contains('checked')");
    $this->assertNotNull($div0, 'DataCommand updates the DOM as expected when a checkbox is selected');
    $session->getPage()
      ->uncheckField('checkbox');
    $div1 = $this->assertSession()
      ->waitForElement('css', "div#ajax_checkbox_value:contains('unchecked')");
    $this->assertNotNull($div1, 'DataCommand updates the DOM as expected when a checkbox is de-selected');
    // Verify that AJAX elements with invalid callbacks return error code 500.
    // Ensure the test error log is empty before these tests.
    $this->assertFileDoesNotExist(DRUPAL_ROOT . '/' . $this->siteDirectory . '/error.log');
    // We don't need to check for the X-Drupal-Ajax-Token header with these
    // invalid requests.
    foreach ([
      'null',
      'empty',
      'nonexistent',
    ] as $key) {
      $element_name = 'select_' . $key . '_callback';
      // Updating the field will trigger an AJAX request/response.
      $session->getPage()
        ->selectFieldOption($element_name, 'green');
      // The select element is disabled as the AJAX request is issued.
      $this->assertSession()
        ->waitForElement('css', "select[name=\"{$element_name}\"]:disabled");
      // The select element is enabled as the response is received.
      $this->assertSession()
        ->waitForElement('css', "select[name=\"{$element_name}\"]:enabled");
      $this->assertFileExists(DRUPAL_ROOT . '/' . $this->siteDirectory . '/error.log');
      $this->assertStringContainsString('"The specified #ajax callback is empty or not callable."', file_get_contents(DRUPAL_ROOT . '/' . $this->siteDirectory . '/error.log'));
      // The exceptions are expected. Do not interpret them as a test failure.
      // Not using File API; a potential error must trigger a PHP warning.
      unlink(\Drupal::root() . '/' . $this->siteDirectory . '/error.log');
    }
    // We need to reload the page to kill any unfinished AJAX calls before
    // tearDown() is called.
    $this->drupalGet('ajax_forms_test_get_form');
  }

}