Shop GUID Algo

shop_cart.rb

require 'digest/md5'

module ShopCartDigestGUID
  private

  def guid_generator
    srand.to_s[1..12]
  end
end

class ShopCart
  attr_accessor :guid

  prepend ::ShopCartDigestGUID
  
  def initialize
    @guid = splitter guid_generator, 4
  end

  private

  def guid_generator
    ::Digest::MD5.hexdigest(srand.to_s)[1..12].upcase
  end

  def splitter value, size = 4
    value.to_s.scan(/.{1,#{size}}/).join(' ')
  end
end

cart = ShopCart.new
puts cart.guid