Javscript execute promises sequentially, subject to delay

delayJobs.js

/**
 * How to execute a list of functions subject to a delay
 */
const interval = 3000
const delay = time => new Promise(resolve => setTimeout(resolve, time))

// in practice, this would be an array of functions with nested callbacks
const fns = Array(3).fill((() => console.log(Date.now())))

// wait for each delay before executing the next function
async function delayJobs () {
  var response = []

  // works
  for(var i = 0; i < fns.length; i++) {
    if(i !== 0) await delay(interval)
    response.push(fns[i]())
  }
  
  // works
  //for(fn of fns) {
  //  await delay(interval)
  //  response.push(fn())
  //}

  // doesn't work, executes in parallel
  //fns.map( async (fn, i) => {
  //  if(i !== 0) await delay(interval)
  //  response.push(fns[i]())
  //})

  return response
}

delayJobs()