require 'ostruct' FactoryBot.define do factory :wiki_page do transient do attrs do { title: 'Title', content: 'Content for wiki page', format: 'markdown' } end end page { OpenStruct.new(url_path: 'some-name') } association :wiki, factory: :project_wiki, strategy: :build initialize_with { new(wiki, page, true) } before(:create) do |page, evaluator| page.attributes = evaluator.attrs end to_create do |page| page.create end end end