Promisified node-postgres

util.js

var pg = require('pg');
var Promise = require('bluebird');

exports.connect = function(config){
  return new Promise(function(resolve, reject){
    pg.connect(config, function(error, connection, next){
      if(error)
        throw error;

      connection.queryAsync = function(){
        var args = arguments.length === 1 ? [arguments[0]] :
                 Array.apply(null, arguments);
        return new Promise(function(resolve, reject){
          args.push(function(error, result){
            if(error)
              throw error;

            return resolve([result, next]);
          });

          connection.query.apply(connection, args);
        });
      }

      resolve(connection);
    });
  });
}