difference between 'util.promisify(setTimeout)' and 'ms => new Promise(resolve => setTimeout(resolve, ms))'

Question

Environment: node 8.11.x I want use async/await for sleep a while.

const sleep = ms => new Promise(resolve => setTimeout(resolve, ms))
await sleep(5000)
         


        

Answer 1

This can be a one-liner: await promisify(setTimeout)(1000).

It works because setTimeout has a custom variant for promisify. It does work with node 8.11.

nvm install 8.11 && nvm use 8.11
node < {
    // const start = Date.now();
    await require('util').promisify(setTimeout)(5000);
    // console.log(Date.now() - start);
  })()
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