Javascript Promises Timeout

promise_timeout.js

// 
// Javascript Promises Timeout
// 
// A way to implement timeouts in jS promises using :
// - setTimeout():
//    sets up a function to be called after a specified delay in milliseconds.
// - Promise.race():
//    Creates a Promise that is resolved or rejected when any of the provided Promises are resolved or rejected.
//
// Run 'seq 10 | xargs -Iz node promise_timeout.js' on the command line to see the results flapping between 'Done' and 'TimeOut'
//  (Tested on node v10.15.3 and Darwin Kernel Version 18.6.0)

const timeOut = async timeout => {
  return new Promise(resolve => {
    const wait = setTimeout(() => {
      clearTimeout(wait)
      resolve('TimeOut')
    }, timeout)
  })
}

const fakeService = async timeout => {
  return new Promise(resolve => {
    const wait = setTimeout(() => {
      clearTimeout(wait)
      resolve('Done')
    }, timeout)
  })
}

const init = async () => {
  const result = await Promise.race([fakeService(501), timeOut(500)])
  console.log(result)
}

init()