mercury_editor-2.0.x-dev/build/js/edit-screen.ajax.js

(function () {
  'use strict';

  ((Drupal) => {
    /**
     * Post a message to the preview iframe.
     * @param {Object} msg The message to post.
     */
    function postMessage(msg) {
      document.getElementById('me-preview').contentWindow.postMessage(msg);
    }
    /**
     * Ajax command wrapper to send a set of ajax commands to iFrame.
     * @param {*} ajax The ajax object.
     * @param {*} response The ajax response.
     * @param {*} status The ajax status.
     */
    Drupal.AjaxCommands.prototype.mercuryEditorEditIframeCommandsWrapper = function (ajax, response, status) {
      postMessage({
        type: 'ajaxCommands',
        settings: {commands: response.commands, status}
      });
    };
  })(Drupal);

})();