A couple of handy timing functions I use often

timing-utils.js

// async
const timeout = n => new Promise(resolve => setTimeout(resolve, n))
// sync
const sleep = n => Atomics.wait(new Int32Array(new SharedArrayBuffer(4)), 0, 0, n)

// async
const scheduleAsync = startAtEpoch => async fn => {
  const now = Date.now()
  const millisecondsTillStartAt = startAtEpoch - now
  await timeout(millisecondsTillStartAt)
  return fn()
}
// sync
const scheduleSync = startAtEpoch => fn => {
  let now
  do {
    now = Date.now()
  } while (now < startAtEpoch)
  fn()
}

// async
const measureAsync = prefix => async fn => {
  const start = process.hrtime()
  console.log(prefix, 'starting at', Date.now())
  await fn()
  const end = process.hrtime(start)
  console.log(prefix, 'took', end[0] + end[1] / 1e9)
}
// sync
const measureSync = prefix => fn => {
  const start = process.hrtime()
  console.log(prefix, 'starting at', Date.now())
  fn()
  const end = process.hrtime(start)
  console.log(prefix, 'took', end[0] + end[1] / 1e9)
}