rack-attack/lib/rack/attack/railtie.rb

# frozen_string_literal: true

module Rack
  class Attack
    class Railtie < ::Rails::Railtie
      initializer 'rack.attack.middleware', after: :load_config_initializers, before: :build_middleware_stack do |app|
        if Gem::Version.new(::Rails::VERSION::STRING) >= Gem::Version.new("5.1")
          middlewares = app.config.middleware
          operations = middlewares.send(:operations) + middlewares.send(:delete_operations)

          use_middleware = operations.none? do |operation|
            middleware = operation[1]
            middleware.include?(Rack::Attack)
          end

          middlewares.use(Rack::Attack) if use_middleware
        end
      end
    end
  end
end