Node.js Async Function Best Practices

[gergelyke]

[gergelyke]

@ksmithut thanks, fixed it!

[xkizer]

async function main () {
  const [user, product] = await Promise.all([
    Users.fetch(userId),
    Products.fetch(productId)
  ])
  await makePurchase(user, product)
}

can also be written as

async function main () {
  const user = Users.fetch(userId)
  const product = Products.fetch(productId)
  await makePurchase(await user, await product)
}

[slavaGanzin]

You do await + callbacks. "Best practices"? For real?

[ksmithut]

@slavaGanzin If you're referring to the express example, express uses callbacks exclusively, no way around it (ATM). So for express, yes, if that's what you're referring to.

[slavaGanzin]

@ksmithut No, I'm talking about last example from this article:

const util = require('util')
const async = require('async')
const numbers = [
  1, 2, 3, 4, 5
]
mapLimitAsync = util.promisify(async.mapLimit)
async function main () {
  return await mapLimitAsync(numbers, 2, (number, done) => {
    setTimeout(function () {
      done(null, number * 2)
    }, 100)
  })
}
main()
  .then(console.log)
  .catch(console.error)

Callbacks, promisified callbacks, await. This code is utter mess

[phelma]

The @sindresorhus promise-fun repo has a bunch of good promise helper modules, as an alternative to using the async module.

https://github.com/sindresorhus/promise-fun