Async await handle Promise { <Pending> } Express API

Question

I got this API controler:

exports.doctorsList = async (req, res) => {
    const users = await User.find().exec();
    let responseArray = await users.map(async (user) => {
        const transaction = await MedicalConsultation.find({
            doctorOwner: user._id,
        }).exec();

        let cpLength = transaction.length;

        return await {
            _id: user._id,
            name: user.name,
            email: user.email,
            specialty: user.specialty,
            role: user.role,
            createdAt: user.createdAt,
            c_p: cpLength,
            status: user.status,
        };
    });

    console.log(responseArray);
    res.json(responseArray);
};

In the console.log I got:

[ Promise { <pending> }, Promise { <pending> }, Promise 
{ <pending> } ]

How is the correct way to write that code? or how to obtain the values?

Answer 1

users.map(async function(){... }) results in an array of promises, you need to await Promise.all(...) on that array of promises.

So instead of:

 let responseArray = await users.map(async (user) => {
   // your code goes here
 });

You need to:

 let responseArray = await Promise.all(users.map(async (user) => {
   // your code goes here
 }));

If you're using bluebird, you can have a slightly nicer API.

const Promise = require('bluebird');

let responseArray = await Promise.map(users, async (user) => {
  // your code goes here
});