Client-side UUID Generator

generateUUID.js

function generateUUID() {
  var d = new Date().getTime()
  if (window.performance && typeof window.performance.now === "function") {
    d += window.performance.now() //use high-precision timer if available
  }
  var uuid = 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function (c) {
    var r = (d + Math.random() * 16) % 16 | 0
    d = Math.floor(d / 16)
    return (c == 'x' ? r : (r & 0x3 | 0x8)).toString(16)
  })
  return uuid
}
module.exports = generateUUID()