drupal/core/misc/jquery.tabbable.shim.js

/**
 * @file
 * Defines a backwards-compatible shim for the jQuery UI :tabbable selector.
 */

(($, Drupal, { isTabbable }) => {
  $.extend($.expr[':'], {
    tabbable(element) {
      Drupal.deprecationError({
        message:
          'The :tabbable selector is deprecated in Drupal 9.2.0 and will be removed in Drupal 11.0.0. Use the core/tabbable library instead. See https://www.drupal.org/node/3183730',
      });

      // The tabbable library considers the summary element tabbable, and also
      // considers a details element without a summary tabbable. The jQuery UI
      // :tabbable selector does not. This is due to those element types being
      // inert in IE/Edge.
      // @see https://allyjs.io/data-tables/focusable.html
      if (element.tagName === 'SUMMARY' || element.tagName === 'DETAILS') {
        const tabIndex = element.getAttribute('tabIndex');
        if (tabIndex === null || tabIndex < 0) {
          return false;
        }
      }
      return isTabbable(element);
    },
  });
})(jQuery, Drupal, window.tabbable);