Use Strong Parameters in a Grape API without Rails

app.rb

require 'rack/test'
require 'action_controller/metal/strong_parameters'

# https://github.com/rails/rails/blob/master/actionpack/test/controller/parameters/parameters_require_test.rb

module Application
  class API < Grape::API

    helpers do
      def item_params
        ActionController::Parameters.new(params).require(:item).permit(:attribute)
      end
    end
    
    desc "Create an item."
    post :items do
      Item.new item_params
    end
  end
end

Gemfile

gem "actionpack", "~> 4.0.0"

our solution without need to include 'action_controller/metal/strong_parameters'

https://gist.github.com/BGuimberteau/4da1ab54e576121edde5

if I'm on a pure Rack, why do I ever need actionpack? https://github.com/ruby-grape/grape/blob/master/grape.gemspec#L15