= factory_girl

written by Joe Ferris <[email protected]> thanks to Tammer Saleh, Dan Croak, and Jon Yurek of thoughtbot, inc. Copyright 2008 Joe Ferris and thoughtbot, inc.

== Defining factories

  1. This will guess the User class Factory.define :user do |u| u.first_name ‘John’ u.last_name ‘Doe’ u.admin false end
  1. This will use the User class (Admin would have been guessed) Factory.define :admin, :class => User do |u| u.first_name ‘Admin’ u.last_name ‘User’ u.admin true end

It is recommended that you create a test/factories.rb file and define your factories there. This file can be included from test_helper or directly from your test files. Don’t forget: require ‘factory_girl’

== Lazy Attributes

Most attributes can be added using static values that are evaluated when the factory is defined, but some attributes (such as associations and other attributes that must be dynamically generated) will need values assigned each time an instance is generated. These “lazy” attributes can be added by passing a block instead of a parameter:

Factory.define :user do |u|
  1. … u.activation_code { User.generate_activation_code } end

== Dependent Attributes

Some attributes may need to be generated based on the values of other attributes. This can be done by calling the attribute name on Factory::AttributeProxy, which is yielded to lazy attribute blocks:

Factory.define :user do |u| u.first_name ‘Joe’ u.last_name ‘Blow’ u.email {|a| “#{a.first_name}.#[email protected]”.downcase } end Factory(:user, :last_name => ‘Doe’).email
  1. => “[email protected]

== Associations

Associated instances can be generated by using the association method when defining a lazy attribute:

Factory.define :post do |p|
  1. … p.author {|author| author.association(:user, :last_name => ‘Writely’) } end

When using the association method, the same build strategy (build, create, or attributes_for) will be used for all generated instances:

  1. Builds and saves a User and a Post post = Factory(:post) post.new_record? # => false post.author.new_record # => false
  1. Builds but does not save a User and a Post Factory.build(:post) post.new_record? # => true post.author.new_record # => true

== Sequences

Unique values in a specific format (for example, e-mail addresses) can be generated using sequences. Sequences are defined by calling Factory.sequence, and values in a sequence are generated by calling Factory.next:

  1. Defines a new sequence Factory.sequence :email do |n| “person#[email protected]” end
Factory.next :email
  1. => “[email protected]
Factory.next :email
  1. => “[email protected]

== Using factories

  1. Build and save a User instance Factory(:user)
  1. Build a User instance and override the first_name property Factory.build(:user, :first_name => ‘Joe’)
  1. Return an attributes Hash that can be used to build a User instance attrs = Factory.attributes_for(:user)