Combination of async function + await + setTimeout

Question

I am trying to use the new async features and I hope solving my problem will help others in the future. This is my code which is working:

  async function as         


        

Answer 1

setTimeout is not an async function, so you can't use it with ES7 async-await. But you could implement your sleep function using ES6 Promise:

function sleep (fn, par) {
  return new Promise((resolve) => {
    // wait 3s before calling fn(par)
    setTimeout(() => resolve(fn(par)), 3000)
  })
}

Then you'll be able to use this new sleep function with ES7 async-await:

var fileList = await sleep(listFiles, nextPageToken)

Please, note that I'm only answering your question about combining ES7 async/await with setTimeout, though it may not help solve your problem with sending too many requests per second.

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Update: Modern node.js versions has a buid-in async timeout implementation, accessible via util.promisify helper:

const {promisify} = require('util');
const setTimeoutAsync = promisify(setTimeout);