Rosie

Rosie is a factory for building JavaScript objects, mostly useful for setting up test data. It is inspired by factory_girl.

Usage

Define your factory, giving it a name and optionally a constructor function:

Factory.define('game', Game)
  .sequence('id')
  .attr('is_over', false)
  .attr('created_at', function() { return new Date(); })
  .attr('random_seed', function() { return Math.random(); })
  .attr('players', function() {
    return [
      Factory.attributes('player'),
      Factory.attributes('player')
    ];
  });

Factory.define('player')
  .sequence('id')
  .sequence('name', function(i) { return 'player' + i; });

Factory.define('disabled-player').extend('player').attr('state', 'disabled')

Now you can build an object, passing in attributes that you want to override:

var game = Factory.build('game', {is_over:true});

Which returns an object that looks roughly like:

{
  id:           1,
  is_over:      true,   // overriden when building
  created_at:   Fri Apr 15 2011 12:02:25 GMT-0400 (EDT),
  random_seed:  0.8999513240996748,
  players: [
                {id: 1, name:'Player 1'},
                {id: 2, name:'Player 2'}
  ]
}

For a factory with a constructor, if you want just the attributes:

Factory.attributes('game') // return just the attributes

You can also define a callback function to be run after building an object:

Factory.define('coach').after(function(coach, options) { if (options.buildPlayer) { Factory.build('player', {coach_id: coach.id}; } })

Factory.build('coach', {}, {buildPlayer: true});

Credits

Thanks to Daniel Morrison for the name and Jon Hoyt for inspiration and brainstorming the idea.