---
title: New Factory Bot Definition Syntax
teaser:
tags: news,web,ruby,testing,open source,factory_girl,factory_bot
author: Dan Croak
published_on: 2011-07-03
---

[`factory_bot`](https://github.com/thoughtbot/factory_bot) and
[`factory_bot_rails`](https://github.com/thoughtbot/factory_bot_rails) release
candidates were released this week thanks to
[Joe](http://thoughtbot.com/about/#jferris) and
[Josh](http://thoughtbot.com/about/#jclayton).

The big change is some great-looking new syntax. Check it out:

Old:

```ruby
Factory.sequence :email do |n|
  "email#{n}@example.com"
end

Factory.define :user do |factory|
  factory.name  { 'Ron Burgundy' }
  factory.email { Factory.next(:email) }
end

Factory.define :admin, parent: :user do |factory|
  factory.admin { true }
end

Factory.define :dog do |factory|
  factory.name { 'Baxter' }
  factory.association(:owner, factory: :user)
end
```

New:

```ruby
FactoryBot.define do
  sequence :email do |n|
    "email#{n}@example.com"
  end

  factory :user, aliases: [:owner] do
    name { 'Ron Burgundy' }
    email

    factory :admin do
      admin { true }
    end
  end

  factory :dog do
    name { 'Baxter' }
    owner
  end
end
```

It reminds me of the difference between Rails 2.x routes and Rails 3.x routes.

Read the [factory_bot book](https://thoughtbot.github.io/factory_bot), then try it in your app:

    gem 'factory_bot_rails', '1.1.rc1'

* * *

**Disclaimer:**

Looking for FactoryGirl? The library was renamed in 2017.
[Project name history can be found here.](https://github.com/thoughtbot/factory_bot/blob/master/NAME.md)