Mongoose await not working

Question

async function main() {
  console.log("Start")
  await Author.create({name: 'Some Guy'}, function (err, awesome_instance) {
    console.log("This should be next, but its not")
  });

  console.log("This should be last, but it's not")
}

main()

The final log statement is logging before the second. Why is this the case if I'm using await?

You need to return a promise and you can use `.then` once the promise is resolved. — Drewness, Feb 13 '18 at 19:06

score 4 · Accepted Answer · edited Feb 13 '18 at 22:32

4

Mongoose methods switch to callback mode when callback is specified, and switch to promise mode when it isn't.

It should be:

async function main() {
  try {
    await Author.create({name: 'Some Guy'});
  } catch (err) {
    console.error(err);
  }
  console.log("This should be next, but its not");
  console.log("This should be last, but it's not");
}

edited Feb 13 '18 at 22:32

Bergi

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answered Feb 13 '18 at 19:33

Estus Flask

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score 0 · Answer 2 · answered Feb 13 '18 at 19:05

0

Your await is waiting for Author.create to return/resolve. But the first log statement is in a callback and is called asynchronously by Author.create, so the await does not apply.

If you implement Author.create using promises you can use await.

answered Feb 13 '18 at 19:05

sliptype

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How do I implement with promise? – Ben G Feb 13 '18 at 19:11
You could use a library like mpromise https://www.npmjs.com/package/mpromise – sliptype Feb 13 '18 at 19:16
1

it seems like just using .then() makes it work? guessing cus then() returns a promise – Ben G Feb 13 '18 at 19:18
Oh cool, the library you are using probably supports both callbacks and promises – sliptype Feb 13 '18 at 20:32

Mongoose await not working

2 Answers2