Accept an array of functions that each return a Promise and execute them in order, waiting for each returned Promise to resolve before continuing to the next function

orderPromises.js

function orderPromises (promiseFns) {
  if (!Array.isArray(promiseFns) || (promiseFns.length && typeof promiseFns[0] !== 'function')) {
    throw new TypeError('orderPromises expects an array of functions. Received: ' + JSON.stringify(promiseFns))
  }

  if (!promiseFns.length) {
    return Promise.resolve()
  }

  const promise = promiseFns[0]()

  if (!promise.then) {
    throw new TypeError('A function in the array passed to orderPromises did not return a promise. Returned: ' + JSON.stringify(promise))
  }

  return promise.then(function () {
    return orderPromises(promiseFns.slice(1))
  })
}