/**
 * Parses an HTML string and syntax highlights all code blocks using Prism.js.
 *
 * @param {String} htmlString - HTML string to process.
 * @param {Object} [options] - Additional options.
 * @param {String} [options.defaultLanguage='markup'] - Fallback language for
 *                                                      code blocks.
 * @param {Boolean} [options.lineNumbers=true] - Specifies whether line numbers
 *                                               should show.
 * @param {Boolean} [options.showLanguage=false] - Specifies whether the
 *                                                 language label should show.
 *
 * @return {Promise<String>} - Promise with the output HTML as the fulfillment
 *                             value.
 */
function prismDOM(htmlString, options)

const prismDOM = require('prism-dom');
 
prismDOM(`<some_html>`, {}).then(htmlString => {
  // The output HTML string with all code elements syntax highlighted.
  console.log(htmlString);
});