Factory Bot is a helper for writing factories for Ruby tests. It was previously known as Factory Girl. For older versions, use FactoryGirl instead of FactoryBot. Factory Bot documentation (rubydoc.info) Getting started (github.com) Source code (github.com) FactoryBot.define do factory :user do first_name { 'John' } last_name { 'Doe' } birthdate { 21.years.ago } admin { false } sequence(:username)