stackoverflow 上面的一个，更加标准一点：

export function uuid() {
  // http://www.ietf.org/rfc/rfc4122.txt
  const s = new Array(36);
  const hexDigits = '0123456789abcdef';
  for (let i = 0; i < 36; i++) {
    const star = Math.floor(Math.random() * 0x10);
    s[i] = hexDigits.substring(star, star + 1);
  }
  s[14] = '4'; // bits 12-15 of the time_hi_and_version field to 0010
  // eslint-disable-next-line no-bitwise
  const star = (s[19] & 0x3) | 0x8; // bits 6-7 of the clock_seq_hi_and_reserved to 01
  s[19] = hexDigits.substring(star, star + 1);
  s[23] = '-';
  s[18] = '-';
  s[13] = '-';
  s[8] = '-';
  return s.join('');
}