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factory_bot_rails Code Climate Gem Version

factory_bot is a fixtures replacement with a straightforward definition syntax, support for multiple build strategies (saved instances, unsaved instances, attribute hashes, and stubbed objects), and support for multiple factories for the same class (user, admin_user, and so on), including factory inheritance.

Transitioning from factory_girl_rails?

Check out the guide.


factory_bot_rails provides Rails integration for factory_bot.

Supported Rails versions are listed in Appraisals. Supported Ruby versions are listed in .github/workflows/build.yml.




$ gem install factory_bot_rails


Add factory_bot_rails to your Gemfile in both the test and development groups:

group :development, :test do
  gem 'factory_bot_rails'

You may want to configure your test suite to include factory_bot methods; see configuration.

Automatic Factory Definition Loading

By default, factory_bot_rails will automatically load factories defined in the following locations, relative to the root of the Rails project:


You can configure by adding the following to config/application.rb or the appropriate environment configuration in config/environments:

config.factory_bot.definition_file_paths = ["custom/factories"]

This will cause factory_bot_rails to automatically load factories in custom/factories.rb and custom/factories/*.rb.

It is possible to use this setting to share factories from a gem:

  require 'factory_bot_rails'
rescue LoadError

class MyEngine < ::Rails::Engine
  config.factory_bot.definition_file_paths +=
    [File.expand_path('../factories', __FILE__)] if defined?(FactoryBotRails)

You can also disable automatic factory definition loading entirely by using an empty array:

config.factory_bot.definition_file_paths = []


Including factory_bot_rails in the development group of your Gemfile will cause Rails to generate factories instead of fixtures. If you want to disable this feature, you can either move factory_bot_rails out of the development group of your Gemfile, or add the following configuration:

config.generators do |g|
  g.factory_bot false

If fixture replacement is enabled and you already have a test/factories.rb file (or spec/factories.rb if using rspec_rails), generated factories will be inserted at the top of the existing file. Otherwise, factories will be generated in the test/factories directory (spec/factories if using rspec_rails), in a file matching the name of the table (e.g. test/factories/users.rb).

To generate factories in a different directory, you can use the following configuration:

config.generators do |g|
  g.factory_bot dir: 'custom/dir/for/factories'

Note that factory_bot_rails will not automatically load files in custom locations unless you add them to config.factory_bot.definition_file_paths as well.

The suffix option allows you to customize the name of the generated file with a suffix:

config.generators do |g|
  g.factory_bot suffix: "factory"

This will generate test/factories/users_factory.rb instead of test/factories/users.rb.

For even more customization, use the filename_proc option:

config.generators do |g|
  g.factory_bot filename_proc: ->(table_name) { "prefix_#{table_name}_suffix" }

To override the default factory template, define your own template in lib/templates/factory_bot/model/factories.erb. This template will have access to any methods available in FactoryBot::Generators::ModelGenerator. Note that factory_bot_rails will only use this custom template if you are generating each factory in a separate file; it will have no effect if you are generating all of your factories in test/factories.rb or spec/factories.rb.

Factory_bot_rails will add a custom generator:

rails generate factory_bot:model NAME [field:type field:type] [options]


Please see

factory_bot_rails was originally written by Joe Ferris and is maintained by thoughtbot. Many improvements and bugfixes were contributed by the open source community.


factory_bot_rails is Copyright © 2008-2020 Joe Ferris and thoughtbot. It is free software, and may be redistributed under the terms specified in the LICENSE file.

About thoughtbot


factory_bot_rails is maintained and funded by thoughtbot, inc. The names and logos for thoughtbot are trademarks of thoughtbot, inc.

We are passionate about open source software. See our other projects. We are available for hire.