歌詞GET 歌詞コピー Chrome拡張

{
  "name": "歌詞GET歌詞コピー",
  "version": "1.0.0",
  "manifest_version": 3,
  "description": "歌詞GET歌詞コピー",
  "content_scripts": [
    {
      "matches": ["http://www.kget.jp/lyric/*"],
      "js": ["./app.js"]
    }
  ]
}

const main = () => {
  const div = document.createElement('div');
  const button = document.createElement('button');
  div.appendChild(button);
  document.querySelector('h1').after(div);

  div.style.textAlign = 'center';

  button.textContent = '歌詞をコピーする';
  button.style.width = '150px';
  button.style.height = '50px';

  button.onclick = () => {
    const listener = e => {
      const str = document.querySelector('#lyric-trunk').textContent.trim();
      const sp = str.split('\n');

      const ret = sp.reduce((acc, value, index) => {
        if (index >= 11 && index <= sp.length - 12) {
          acc += value + '\n';
        }
        return acc;
      }, '');

      e.clipboardData.setData('text/plain', ret.trim());
      e.preventDefault();
      document.removeEventListener('copy', listener);
    };

    document.addEventListener('copy', listener);
    document.execCommand('copy');
    alert('歌詞をコピーしました');
  };
};

main();