Would this work with await?

[dbeja]

Hi,

I have something like this:

import {RateLimiter} from 'limiter';
const dynamoDBLimiter = new RateLimiter(10, 'second');
console.log('before removeTokens');
for(let contact_i = 0; contact_i < company.contacts.length; contact_i++) {
  dynamoDBLimiter.removeTokens(1, async function(err, remainingRequests) {
    console.log('adding contact');
    newContact = await addContact(contact_i);
    console.log('new contact added');
  });
}
console.log('end of removeTokens');

But the logs I get are like this:

before removeTokens
end of removeTokens
adding contact
new contact added

Am I doing something wrong? Thanks!

[dbeja]

Ok, figured it out. This is a callback so removeTokens wouldn't be waiting for the function to finish. I just added the rest of the code needed after getting the contact inside removeTokens callback and it's working fine!

[jhurliman]

You would need to wrap the callback-based API with a Promise to make it compatible with async/await. Something like this:

import {RateLimiter} from 'limiter';

main()

async function main() {
  const dynamoDBLimiter = new RateLimiter(10, 'second');
  console.log('before removeTokens');
  for(let contact_i = 0; contact_i < company.contacts.length; contact_i++) {
    await removeTokens(1, dynamoDBLimiter)
    console.log('adding contact');
    const newContact = await addContact(contact_i);
    console.log('new contact added');
  }
  console.log('end of removeTokens');
}

function removeTokens(count, limiter) {
  return new Promise((resolve, reject) => {
    limiter.removeTokens(count, (err, remainingRequests) => {
      if (err) return reject(err)
      resolve(remainingRequests)
    })
  })
}