mongodb nodejs db.collection is not a function

Question

This is my FollowerModel class (in ES6) representing follower collection of my MongoDB

import mongo from 'mongodb';

class FollowerModel {

    constructor(db, logger) {
        this._db = db;
        this._logger = logger;
    }

    async create(data) {
        try {
            data._id = mongo.ObjectID().toString();
            return await this._db.collection('follower').insertOne(data);
        } catch (error) {
            return Promise.reject(error);
        }
    }

}

export default FollowerModel;

And this is my unit test

import chai from 'chai';
import chaiAsPromised from 'chai-as-promised';
import { expect } from 'chai';
import mongo from 'mongodb';
import mongo_url from '../../config/mongodb';
import logger from '../../config/logger';
import to from 'await-to-js';
import FollowerModel from '../../model/follower';

const MongoClient = mongo.MongoClient;
const data = {
    email: 'my_email',
    phone: 'my_phone',
    code: 'my_code'
};

describe('Model: Follower', () => {

    let Follower;
    let connected = false;
    let _db;

    const connect = () => {
        try {
            const db = await MongoClient.connect(mongo_url);
            Follower = new FollowerModel(db, logger);
            connected = true;
            _db = db;
            return Promise.resolve();
        } catch (error) {
            return Promise.reject(error);
        }
    };

    before(() => connect());

    describe('create', () => {
        let _id;
        beforeEach(() => connected ? null : connect());
        it('Returns with insertedId', async () => {
            const [, result] = await to(Follower.create(data));
            return expect(result).to.have.property('insertedId');
        });
        afterEach(() => connected ?
            _db.collection('follower').deleteOne({ _id }) : connect().then(() => _db.collection('follower').deleteOne({ _id }))
        );
    });

});

This test fails, the error is this._db.collection is not a function much to my frustration. As I initialize Follower instance, db is passed to the constructor, initializing db successfully in class. I even tried to console.log both db and db.collection. It does log db as expected but returns undefined for db.collection. This confuses me

Possible duplicate of db.collection is not a function when using MongoClient v3.0 — Mika Sundland
– Mika Sundland, Commented Dec 22, 2017 at 11:00

edkeveked · Accepted Answer · 2017-12-22 07:59:37Z

1

Since the V3+ of the MongoDB native NodeJS driver:

const db = await MongoClient.connect(mongo_url);

_db = db.db("nameOfyourDataBase");

//then you can use _db.collection

edited Dec 22, 2017 at 7:59

answered Dec 22, 2017 at 7:38

edkeveked

18.4k10 gold badges60 silver badges95 bronze badges

Sign up to request clarification or add additional context in comments.

6 Comments

necroface Over a year ago

I couldn't understand. I already declared mongo_url which includes db host, credentials and name

edkeveked Over a year ago

maybe you simply have to put in your url db host and credentials

necroface Over a year ago

I log it to check, mongo_url returns mongodb://localhost/mydb, which does fit connection string that includes host, credentials, and name

necroface Over a year ago

It did, much to my surprise. But I want to understand why it happened. I used this same practice in my old project, which worked perfectly

necroface Over a year ago

As I inspected, this is a bug of new version of node-mongodb-native package. When I switched to the old version of my old project (v2.2.28) instead of the newest v3.0.0, it worked perfectly

|

Collectives™ on Stack Overflow

mongodb nodejs db.collection is not a function

1 Answer 1

6 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

6 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related