Issue promisifying node-mysql

I would expect the following two code fragments to output the same thing:

Promise = require 'bluebird'
mysql = require 'mysql'
Promise.promisifyAll(require("mysql/lib/Pool").prototype)
Promise.promisifyAll(require("mysql/lib/Connection").prototype)

pool = mysql.createPool { database: 'mydb', host: 'localhost', user: 'user', password: 'pw' }

pool.getConnectionAsync().then (db) ->
  db.queryAsync('select * from users where id=?', '1').then (rows) ->
    console.log rows

mysql = require 'mysql'

pool = mysql.createPool { database: 'mydb', host: 'localhost', user: 'user', password: 'pw' }

pool.getConnection (err, db) ->
  db.query('select * from users where id='?', '1', (err, rows) ->
    console.log rows

However for the first, the output looks like:

[ [ { id: 1, email: 'myemail', password: 'pw' } ],
      [ { catalog: 'def',
  db: 'mydb',
  table: 'users',
  orgTable: 'users',
  name: 'id',
  orgName: 'id',
  charsetNr: 63,
  length: 64,
  type: 8,
  flags: 20483,
  decimals: 0,
  default: undefined,
  zeroFill: false,
  protocol41: true }, ...
] ]

and for the second the output is just:

 [ { id: 1, email: 'myemail', password: 'pw' } ] 

I’m still digging in, but wanted to post an issue to see if this is a known problem (or if it’s a case of PEBKAC)

[derdrdirk]

@Prieston no. You need to release it yourself. Have a look at Bluebirds .disposer()

[petkaantonov]

Mysql doesn’t strictly conform to node callback convention, the callback parameters are actually: is err, rows, columns which doesn’t map to single return value. So the promise fulfillment value is [rows, columns] instead of just rows like you expected, to avoid information loss.

You can use spread instead:

pool.getConnectionAsync().then (db) ->
  db.queryAsync('select * from users where id=?', '1').spread (rows, columns) ->
    console.log rows

This cannot be fixed until 3.0.0, see https://github.com/petkaantonov/bluebird/issues/307