app/controllers/orders_controller.rb

orders_controller.rb

class OrdersController < ApplicationController

  before_action :authenticate_user!

  def create
    @order = current_user.orders.build(order_params)

    if @order.save
      @order.build_item_cache_from_cart(current_cart)
      @order.calculate_total!(current_cart)
      redirect_to root_path
    else
      render "carts/checkout"
    end
  end

  private

  def order_params
    params.require(:order).permit(:info_attributes => [:billing_name, :billing_address,:shipping_name, :shipping_address] )
  end

end