htmlparser2.js：一个快速宽松的HTML/XML解析器

npm install htmlparser2

import { Parser } from "htmlparser2";
/**
 * 解析出所有类名
 * @param {String} html
 * @returns {Array}
 */
function extractClassList(html) {
  let classList = [];
  const parser = new Parser({
    onattribute(name, value) {
      if (name == "class") {
        classList.push(value);
      }
    },
  });
  parser.write(html);
  parser.end();
  return classList;
}
const html =
  '<div class="box"><div class="box__header" style="color:#333;"></div><div class="box__body"></div></div>';
let classList = extractClassList(html);
console.log(classList);
// [ 'box', 'box__header', 'box__body' ]