dataaccess.js

var db = require('mongodb'),
    server = new db.Server('alex.mongohq.com', 10053, {auto_reconnect: true}),
    con = new db.Db('consentiment', server);

// callback: (err)
exports.connect = function(callback) {
  con.open(function opened(err, db) {
    if (err) return callback(err);
    //return callback(false, db);
    //return false;
    console.log('connected to db');
    db.authenticate('adam', '', function authenticated(err, result){
      if (err) return callback(err);
      if (!result) return callback(new Error('authentication failed'));
      console.log('authenticated as adam');
      callback(err);
      console.log('came back from call back');
      db.close();
      throw new Error('escape');
    });
  });
}
// callback: (err, collection)
exports.getSubscriptions = function(callback) {
    //callback(false, 'test');
    //return;
    con.collection('companies', function(err, companies) {
    if (err) return callback(err, null);
    companies.find(function(err, cursor) {
      cursor.toArray(function(err, companies) {
        for (i=0;i<companies.length;i++) callback(err, companies[i].company);
      });
    });
  });
}

nodeexample.js

//var url = require('url');
var log = console.log;
//var twitter = require('./twitter.js');
var dataaccess = require('./dataaccess.js');

//twitter.get_tweets('telus', 0, function(tweets) {
  //log(JSON.stringify(tweets, null, '\t'));
//});

var main = function() {
  dataaccess.getSubscriptions(function (err, company) {
    if (err) throw err;
    log(company);
  });
}

dataaccess.connect(function(err, db) {
  if (err) throw err;
  main();
});