wblog/spec/factories/posts.rb

FactoryBot.define do
  factory :post do
    title { 'this is a post title' }
    content { 'content' * 10 }
  end

  factory :post_list, class: Post do
    sequence(:title) { |n| "#{n}: post title" }
    content { 'content' * 10 }
    sequence(:created_at) { |n| n.days.ago }
  end
end