factory_bot_rails

To use factory_bot_rails in a Rails project, add it to your Gemfile within the :development and :test groups.

group :development, :test do
  gem 'factory_bot_rails'
end

Factories have access to the ActiveSupport::Testing::FileFixtures#file_fixture helper. You can disable this support by setting file_fixture_support to false in your configuration.

config.factory_bot.file_fixture_support = false

When factory_bot_rails is in your :development group, Rails will generate factories instead of fixtures. You can customize this behavior using the config.generators block.

# Disable factory generation via generators
config.generators do |g|
  g.factory_bot false
end

# Specify a custom directory for generated factories
config.generators do |g|
  g.factory_bot dir: 'custom/dir/for/factories'
end

# Add a suffix to generated filenames (e.g., users_factory.rb)
config.generators do |g|
  g.factory_bot suffix: "factory"
end

# Use a proc to customize filenames
config.generators do |g|
  g.factory_bot filename_proc: ->(table_name) { "prefix_#{table_name}_suffix" }
end

By default, factory_bot_rails automatically loads factories from factories.rb, test/factories.rb, spec/factories.rb, and any .rb files in factories/, test/factories/, or spec/factories/ relative to the Rails root.

You can customize these paths using config.factory_bot.definition_file_paths. To disable automatic loading entirely, set this to an empty array.

When config.factory_bot.file_fixture_support is set to true (which is the default), factory_bot_rails integrates file fixture support into your test suite.

It automatically configures the FactoryBot::SyntaxRunner to work with file fixtures in both ActiveSupport::TestCase and RSpec environments.

You can configure factory_bot_rails via the Rails configuration object using config.factory_bot.

Available configuration keys:

• definition_file_paths: An array of paths (relative to Rails.root) where your factory definitions are located. By default, this uses FactoryBot.definition_file_paths.
• validator: An instance of FactoryBotRails::FactoryValidator used for validating factories.
• file_fixture_support: A boolean that enables or disables support for file fixtures. Defaults to true.

Use the custom factory_bot:model generator to create a new factory file. The syntax allows you to specify the model name and its attributes.

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

Use the factory_bot:model generator to create a factory file for a specific Rails model. You can pass attributes directly to the command to pre-populate the factory definition.

Arguments

• attributes: An array of field:type pairs (e.g., name:string email:string) to define the factory's attributes.

Options

• --dir: The directory or file root where the factory file should be placed. Defaults to test/factories.
• --suffix: A suffix to add to the generated factory filename.

If the target file already exists, the generator will attempt to insert the new factory definition into the existing file after the FactoryBot.define do block.