Bluebird mongodb disposer

connect.js

// tested with mongodb 2.2.25
const MongoClient=require('mongodb').MongoClient
const Promise = require('bluebird')

module.exports = (connOpts) => {
    return MongoClient
        .connect(connOpts, {promiseLibrary: Promise})
        // .then(db => db)      /* not necessary */
        .disposer(db => {
            console.log('to disconnect')
            db.close()
        })
}

insert.js

const Promise = require('bluebird')
const conn = require('./connect')

Promise.using(conn('mongodb://localhost:27017/test'), db => {
    const col = db.collection('colThing')
    col.insert({name: 'something', value: 1234})
})