weird mongoose behavior

test.coffee

step    = require 'step'
mongoose = require 'mongoose'
Schema = mongoose.Schema

schemas = {}
schemas.Foobar = new Schema
  name : { type: String, trim: true, required: true, unique: true }

connection = mongoose.createConnection 'mongodb://127.0.0.1:27017/sandbox'
models = {}
models.Foobar  = connection.model 'Foobar', schemas.Foobar

foobar = new models.Foobar
  name: 'FOOOOO'

step () ->
  models.Foobar.find {}, this
, (err, docs) ->
  console.log 'found docs', docs

  console.log 'disconnecting'
  mongoose.disconnect this
, (err) ->
  throw err if err
  console.log 'disconnected'