mongo.js when not using schemas

var EventEmitter = require('events').EventEmitter;
var log = require('debug')('mongo');
var client = require('mongodb').MongoClient;
var util = require('util');

function Mongo () {
  EventEmitter.call(this);
}

util.inherits(Mongo, EventEmitter);

Mongo.prototype.connect = function connect (mongoUrl) {
  var self = this;

  client.connect(mongoUrl, function (err, db) {
    if (err) {
      log('✗ MongoDB Connection Error. Please make sure MongoDB is running: ', err);
      self.emit('error', err);
    }

    self.db = db;

    self.collectionOne = db.collection('collectionOne');
    self.collectionTwo = db.collection('collectionTwo');
    self.collectionThree = db.collection('collectionThree');
    log('initialized connection to mongo at %s', mongoUrl);

    self.emit('connected', db);

  });

};

module.exports = new Mongo();