Mongoose: How to use async/await with statics method?

[joetidee]

Please see:

http://stackoverflow.com/questions/41559541/mongoose-await-is-a-reserved-word

[varunjayaraman]

You're using async/await incorrectly. The callback function has to be an async function as well, i.e.:

this.model('Template').findById(id, async function (err, doc) {
        let ref = await getNextSequence();
        ...
    });

To be honest, if you're going to use async/await, you should just use promises (findById returns a Promise if you don't pass it a callback).

try {
  const doc = await this.model('Template').findById(id);
  let ref = await getNextSequence();
  ...
} catch (error) {
  handleError(error);
}

This avoids nested async function bugs like this that can be tricky to catch.

[inanmadak]

@varunjayaraman
try {
const doc = await this.model('Template').findById(id);
let ref = await getNextSequence();
...
} catch (error) {
handleError(error);
}

In an Express middleware,

dbtitle = await Title.find({id: req.params.id}).exec();
^^^^
the code above code does not work on me. Getting unexpected identifier error on Title.
Both code logically the same. Both returns promises.

[varunjayaraman]

@inanmadak i can't repro without a full repro script. I've done something similar to that many times with async/await and it has worked for me

[vkarpov15]

The unexpected identifier error is a syntax error that usually means that await is used in a function that isn't marked async. For example, the below function will error:

async function test() {
  [1, 2].forEach(function() {
    await new Promise(resolve => setTimeout(() => resolve(), 50);
  });
}

Because await is inside the closure passed to forEach(), which is not async. I wrote a couple articles on async/await to help people grok the fundamentals:

• http://thecodebarbarian.com/80-20-guide-to-async-await-in-node.js
• http://thecodebarbarian.com/common-async-await-design-patterns-in-node.js
• http://thecodebarbarian.com/common-async-await-design-patterns-in-node.js

Make sure you check them out if you're new with async/await