Convert time string format "hh:mm:ss" or "mm:ss" or "ss" to seconds

convertHHMMSSToSeconds

const convertHHMMSSToSeconds = timeStr => {
  let p = timeStr.split(':'),
    s = 0,
    m = 1;

  while (p.length > 0) {
    s += m * parseInt(p.pop(), 10);
    m *= 60;
  }

  return s;
};