db.js

"use strict";
const appConfig = require('../config.js');
const mongoose = require('mongoose');
mongoose.connect(appConfig.MONGOLAB_URI);
mongoose.connection.on('error', (err) => {
    console.log('Error: Could not connect to MongoDB. Did you forget to run `mongod`?');
});
mongoose.connection.once('open', (err) => {
    console.log('Connected to MongoDb');
});