(node:3341) DeprecationWarning: Mongoose: mpromise

I'm trying to develop a class on the top of the mongoose with my custom methods, so I extended the mongoose with my own class but when I invoke to create a new car method it works but its strip and error, here I let you see what I'm trying to do.

I'm getting this warning

(node:3341) DeprecationWarning: Mongoose: mpromise (mongoose's default promise library) is deprecated, plug in your own promise library instead: http://mongoosejs.com/docs/promises.html

after I do

driver.createCar({
      carName: 'jeep',
      availableSeats: 4,
    }, callback);

driver is an instance of Driver class

const carSchema = new Schema({
  carName: String,
  availableSeats: Number,
  createdOn: { type: Date, default: Date.now },
});
const driverSchema = new Schema({
 email: String,
 name: String,
 city: String,
 phoneNumber: String,
 cars: [carSchema],
 userId: {
   type: Schema.Types.ObjectId,
   required: true,
 },
createdOn: { type: Date, default: Date.now },
});
const DriverModel = mongoose.model('Driver', driverSchema);

class Driver extends DriverModel {
  getCurrentDate() {
  return moment().format();
}
create(cb) {
  // save driver
  this.createdOn = this.getCurrentDate();
  this.save(cb);
}
remove(cb) {
  super.remove({
  _id: this._id,
 }, cb);
}
createCar(carData, cb) {
  this.cars.push(carData);
  this.save(cb);
}
getCars() {
  return this.cars;
 }
}

any thoughts about what Im doing wrong?

Solution 1:

Here's what worked for me to clear up the issue, after reading docs: http://mongoosejs.com/docs/promises.html

The example in the doc is using the bluebird promise library but I chose to go with native ES6 promises.

In the file where I'm calling mongoose.connect:

mongoose.Promise = global.Promise;
mongoose.connect('mongodb://10.7.0.3:27107/data/db');

[EDIT: Thanks to @SylonZero for bringing up a performance flaw in my answer. Since this answer is so greatly viewed, I feel a sense of duty to make this edit and to encourage the use of bluebird instead of native promises. Please read the answer below this one for more educated and experienced details. ]

Solution 2:

While the answer above is accurate and works, you have to account for the issue of Performance if you have a real, production Node app.

The solution above will use native ES6 promises - which are 4X slower than bluebird in the benchmarks I've shared below. This could dramatically affect the performance of an API written in Node and using MongoDB.

I recommend using Bluebird:

// Assuming you store the library in a var called mongoose
var mongoose = require('mongoose');

// Just add bluebird to your package.json, and then the following line should work
mongoose.Promise = require('bluebird');

Benchmark Results

Platform: (using latest Node at time of writing)

• Linux 4.4.0-59-generic x64
• Node.JS 6.9.4
• V8 5.1.281.89
• Intel(R) Core(TM) i7-6500U CPU @ 2.50GHz × 4
• 16 GB RAM with 500 GB SSD

    | file                                      | time(ms) | memory(MB) |
    |-------------------------------------------|----------|------------|
    | callbacks-baseline.js                     | 114      | 25.09      |
    | callbacks-suguru03-neo-async-waterfall.js | 152      | 32.98      |
    | promises-bluebird-generator.js            | 208      | 29.89      |
    | promises-bluebird.js                      | 223      | 45.47      |
    | promises-cujojs-when.js                   | 320      | 58.11      |
    | promises-then-promise.js                  | 327      | 64.51      |
    | promises-tildeio-rsvp.js                  | 387      | 85.17      |
    | promises-lvivski-davy.js                  | 396      | 81.18      |
    | callbacks-caolan-async-waterfall.js       | 527      | 97.45      |
    | promises-dfilatov-vow.js                  | 593      | 148.30     |
    | promises-calvinmetcalf-lie.js             | 666      | 122.78     |
    | generators-tj-co.js                       | 885      | 121.71     |
    | promises-obvious-kew.js                   | 920      | 216.08     |
    | promises-ecmascript6-native.js            | 931      | 184.90     |
    | promises-medikoo-deferred.js              | 1412     | 158.38     |
    | streamline-generators.js                  | 1695     | 175.84     |
    | observables-Reactive-Extensions-RxJS.js   | 1739     | 218.96     |
    | streamline-callbacks.js                   | 2668     | 248.61     |
    | promises-kriskowal-q.js                   | 9889     | 410.96     |
    | observables-baconjs-bacon.js.js           | 21636    | 799.09     |
    | observables-pozadi-kefir.js               | 51601    | 151.29     |
    | observables-caolan-highland.js            | 134113   | 387.07     |

Solution 3:

did you try this? For Example :

const mongoose = require('mongoose')
mongoose.Promise = global.Promise // <--
const Schema = mongoose.Schema
const UserSchema = new Schema({
  name: String,
})
const User = mongoose.model('user', UserSchema)
module.exports = User

if you create a model from a mongoose instance who's promise wasn't redefined - every query on this model would throw the warning.