magento-test/app/code/Magento/Translation/view/frontend/web/js/add-class.js

/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */

define(['jquery'], function ($) {
    'use strict';

    return function (config, element) {
        $(element).addClass(config.class);
    };
});