Ruby: When and how to use factories for seeding? /2

setup.rb

# Gemfile
group :development, :test do
  gem 'factory_bot_rails', require: false
end

# For testing:
# spec_helper.rb / rails_helper.rb
require 'factory_bot_rails'

# For other envs, e.g. development
# seeds.rb
require 'factory_bot_rails'