记录youtube字幕

gistfile1.js

;(() => {
  const mergeText = (str, text) => {
    if (str === '') {
      return text;
    }
    if (!text || text === ' ' || str === text) {
      return str;
    }
    str = str.replace(/\s+/g, ' ')
             .replace(/\t|\r|\n/g, '');
    const words = str.split(' ').filter(w => w.trim() !== '').map(w => w.trim());
    var i = words.length;
    var regex = s => new RegExp(`${ s.replace(/' '/g, '\s+') }$`, 'i');
    while(!regex(words.slice(0, i).join(' ').trim()).test(text.trim()) && i > 0) {
      i--;
    }
    return `${ text } ${ words.slice(i === words.length ? i + 1 : i).join(' ').trim() }`.trim();
  }

  let scripts = '';
  let timer;
  const record = () => {
    const targetNode = document.querySelector('.captions-text');
    if (targetNode) {
      scripts = mergeText(targetNode.innerText, scripts);
      console.clear();
      console.log(scripts);
    }
    timer = setTimeout(() => record(), 100);
  }
  window.__stopRecord = () => clearTimeout(timer);
  record();
})();