Factory Boy

Factory Boy is an library for Node.js which provides factories for objects creation. It's highly inspired by the fabulous factory_girl library for Ruby on Rails.

It comes with support for :

• associations
• lazy attributes
• defining factory initialization and creation methods

Installation

npm install factory-boy

Defining factories

Factory = require('factory-boy').Factory

Factory.define 'user', class: User, ->
  @first_name = 'John'
  @last_name = 'Smith'
  @pin = (callback) -> callback(null, Math.floor(Math.random()*10000))


Factory.build 'user', (err, user) ->
  console.log user


Factory.create 'user', (err, user) ->
  console.log user

Custom intialization and creation methods

Factory Boy use initializeWith and createWith methods for building and creating factory objects :

initializeWith: (klass, attributes, callback) ->
  callback(null, new klass(attributes))

createWith: (klass, attributes, callback) ->
  klass.create(attributes, callback)

You can overwrite this methods on global level or per each factory :

# overwriting globally
Factory = require('factory-boy').Factory

Factory.initializeWith = (klass, attributes, callback) ->
  callback(null, new klass.build(attributes))

Factory.createWith = (klass, attributes, callback) ->
  new klass.build(attributes).create(callback)

# overwriting per factory

Factory.define 'user', class: User, ->
  @initializeWith = (klass, attributes, callback) ->
    callback(null, klass.build(attributes))

  @createWith = (klass, attributes, callback) ->
    new klass.build(attributes).create(callback)

Lazy attributes

Attributes defined by functions are evaluated upon object intialization/creation. Lazy functions context are set to factory instance so it's possible to use already defined attributes.

Factory.define 'user', class: User, ->
  @first_name = 'John'
  @salt = (callback) ->
    time = new Date()
    callback(null, "@{first_name}#{time}")

Additionally lazy functions are evaluated in the defined order.

Factory.define 'user', class: User, ->
  @number1 = (callback) -> callback(null, 10)
  @number2 = (callback) -> callback(null, @number1 + 10)

Sequences

Sequences can be used for creating record with unique attributes i.e. emails. They are creating lazy attribute for given field with iterator passed as first argument.

Factory.define 'user', class: User, ->
  @sequence 'email', (n, callback) ->
    callback(null, "test#{n}example.com")

First variable in callback will be increment for each records, starting from value 1. Therefore creating user factories will return records with unique emails.

Sequences are also evaluated in the defined order.

Factory.define 'user', class: User, ->
  @number1 = (callback) -> callback(null, 10)
  @number2 = (callback) -> callback(null, @number1 + 10)

Associations

Factory.define 'user', class: User, ->
  @first_name = 'John'
  @association('profile')

Factory.define 'profile', class: Profile, ->
  @avatar_url = 'http://example.com/img.png'

Factory.create 'user', (err, user) ->
  console.log user.profile_id

When using associations you can pass field name as first parameter.

Factory.define 'user', class: User, ->
  @first_name = 'John'
  @association('user_profile_id', profile')

Also you can set values to associated factory.

Factory.define 'user', class: User, ->
  @first_name = 'John'
  @association('profile', avatar_url: 'http://example.com/img2.png')

By default Factory Boy will use id field from associated factory. This can be changed by passing factory options.

Factory.define 'user', class: User, ->
  @first_name = 'John'
  @association('profile', factory: {field: 'external_id'})

Contributing

1. Fork it
2. Install dependencies

npm install

3. Make your changes on branch and make sure all tests pass

npm test

4. Submit your pull request !