parse-time.js

/**
 * Parse a duration string
 *
 * A duration string is a sequence of decimal numbers, each with optional
 * fraction and a unit suffix such as "300ms", "1.5h", "2h45m12s" etc.
 *
 * Valid units are: "h", "m", "s", "ms"
 *
 * A decimal without unit is considered to be a second, e.g. "1m13" === "1m13s".
 *
 * @param {String} duration - Duration string formatted as specified above
 * @returns {Number} The parsed duration in seconds
 */
const parseDuration = (duration) =>
  duration
    .match(/(\d+(\.\d+)?(ms|s|m|h)?)/g)
    .map((t) => {
      if (t.slice(-1) === "h") {
        return parseFloat(t.slice(0, -1)) * 3600;
      }
      if (t.slice(-1) === "m") {
        return parseFloat(t.slice(0, -1)) * 60;
      }
      if (t.slice(-2) === "ms") {
        return parseFloat(t.slice(0, -2)) / 1000;
      }
      return parseFloat(t);
    })
    .reduce((acc, cur) => acc + cur);