Find unused rails routes

unused_rails_routes.rb

# There could likely be some false positives from this
Rails.application.routes.routes.select do |r|
  name = r.defaults[:controller].to_s.classify + "Controller"
  klass = name.constantize rescue nil

  if klass.nil?
    name = r.defaults[:controller].to_s.classify.pluralize + "Controller"
    klass = name.constantize rescue nil
  end

  klass.nil? || !klass.action_methods.include?(r.defaults[:action])
end