types = ["friend", "teacher", "student", "schoolmate", "parent", "best friend", "instructor", "labmate", "TA", "mate"] FactoryGirl.define do factory(:relations, class: "CoAuthorRelation") do |f| f.sequence(:relation_translations) do |n| { zh_tw: "#{types[n%types.size]}", en: "#{types[n%types.size]}" } end end end