I'm really struggling with running a simple test asyncronously with should.js, and node-redis.

if I do use callback(user)

setting up…
done setting up…
inside findByDevice:
  ✓ User #findByDevice should do something useful: 1ms
  1) User #findByDevice should do something useful
inside device fetch
true

  ✖ 1 of 1 test failed:

  1) User #findByDevice should do something useful:
     TypeError: Cannot read property 'should' of undefined
      at /Users/chrisadams/Code/herenow-2012/test/herenow/users.js:29:12
      at User.findByDevice (/Users/chrisadams/Code/herenow-2012/herenow/db/user.js:67:10)
      at Context.<anonymous> (/Users/chrisadams/Code/herenow-2012/test/herenow/users.js:27:9)
      at Test.Runnable.run (/Users/chrisadams/Code/herenow-2012/node_modules/mocha/lib/runnable.js:187:15)
      at Runner.runTest (/Users/chrisadams/Code/herenow-2012/node_modules/mocha/lib/runner.js:307:10)
      at Runner.runTests.next (/Users/chrisadams/Code/herenow-2012/node_modules/mocha/lib/runner.js:353:12)
      at next (/Users/chrisadams/Code/herenow-2012/node_modules/mocha/lib/runner.js:235:14)
      at Runner.hooks (/Users/chrisadams/Code/herenow-2012/node_modules/mocha/lib/runner.js:244:7)
      at next (/Users/chrisadams/Code/herenow-2012/node_modules/mocha/lib/runner.js:192:23)
      at Runner.hook (/Users/chrisadams/Code/herenow-2012/node_modules/mocha/lib/runner.js:207:7)
      at done (/Users/chrisadams/Code/herenow-2012/node_modules/mocha/lib/runnable.js:178:5)
      at Runnable.run.duration (/Users/chrisadams/Code/herenow-2012/node_modules/mocha/lib/runnable.js:190:9)
      at try_callback (/Users/chrisadams/Code/herenow-2012/node_modules/redis/index.js:484:9)
      at RedisClient.return_reply (/Users/chrisadams/Code/herenow-2012/node_modules/redis/index.js:555:13)
      at RedisReplyParser.RedisClient.init_parser (/Users/chrisadams/Code/herenow-2012/node_modules/redis/index.js:256:14)
      at RedisReplyParser.EventEmitter.emit (events.js:88:17)
      at RedisReplyParser.send_reply (/Users/chrisadams/Code/herenow-2012/node_modules/redis/lib/parser/javascript.js:281:18)
      at RedisReplyParser.execute (/Users/chrisadams/Code/herenow-2012/node_modules/redis/lib/parser/javascript.js:135:22)
      at RedisClient.on_data (/Users/chrisadams/Code/herenow-2012/node_modules/redis/index.js:440:27)
      at Socket.<anonymous> (/Users/chrisadams/Code/herenow-2012/node_modules/redis/index.js:70:14)
      at Socket.EventEmitter.emit (events.js:88:17)
      at TCP.onread (net.js:396:14)

if I dont call callback()

setting up…
done setting up…
inside findByDevice:
inside device fetch
true
User: user
  1) User #findByDevice should do something useful

  ✖ 1 of 1 test failed:

  1) User #findByDevice should do something useful:
     Error: timeout of 2000ms exceeded
      at Object.<anonymous> (/Users/chrisadams/Code/herenow-2012/node_modules/mocha/lib/runnable.js:158:14)
      at Timer.list.ontimeout (timers.js:101:19)

user-tests.js

require('../setup')
require('should')
var db = require('../../lib/db')
var User = require('../../herenow/db/user')

describe('User', function() {
  describe('#findByDevice', function() {

    beforeEach(function(done) {
      console.log('setting up…')
      db.hmset("mrchrisadams", {
        name: "Chris Adams",
        username: "mrchrisadams",
        devices: ["00:1e:c2:a4:d3:5e"],
        email_address: "wave@chrisadams.me.uk"
      }, done);
      console.log('done setting up…')

    })

    it('should do something useful', function(done) {

      var u = new User();
      u.findByDevice('00:1e:c2:a4:d3:5e', function(err, chris) {

        done()
        chris.should.have.property('username')
        console.log("logging a spec from inside u.findByDevice")
      });

    }) // close it should do something useful spec

  }) // close describe #findByDevice function

})

user.js

// Example User attributes
// {
//   name: "Chris Adams"
//   username: "mrchrisadams"
//   devices: ["00:1e:c2:a4:d3:5e"]
//   email_address: wave@chrisadams.me.uk
// }
            
var sys = require('util'),
    fs = require('fs'),
    events = require('events'),
    db = require('../../lib/db'); // db is a module wrapper for redis.createClient();


// basic boiler plate
function User() {
  if(false === (this instanceof User)) {
    return new User();
  }
  events.EventEmitter.call(this);
}
sys.inherits(User, events.EventEmitter);

User.prototype.toString = function() {
  return "User"
}

// Tries to find the corresponding user for the device mac passed in, after checking we have this mac
// registered first

// interface_name - the String giving an interface name, like `en1` or `en0`
// device_mac - the String representing the mac address we're using as a key, like `'00:1e:c2:a4:d3:5e'`

User.prototype.findByDevice = function(device_mac, callback) {
  
  // look in redis for mac address, using hget with the device's mac as the key
  // then return the user keying on the user's username
  var user = db.hgetall(device_mac, function (err, device) {
      // console.log("User: device")
      // console.log(device)
    if (device.hasOwnProperty('mac')) { 

      db.hgetall(device.owner, function (err, user) {
        console.log("User: user")
        // console.log(user)
        return user
      })
    }
    //  
    console.log("inside device fetch")
    console.log(user)

    return user
    
  });
  console.log("inside findByDevice:")
  return user
// calling callback(user) returns  from the function, but doesn't return the user object 
// I want to return. how do I return it? 
}







module.exports = User;