product_with_method_missing

product_with_method_missing.rb

class Product
    attr_accessor :name, :variants

    def initialize price, sku,
         master = Variant.new(price: price, sku: sku, is_master: true)
      @variants = [master]
    end
    def add_variant(variant)
        @variants << variant
    end

    def method_missing method, *args
        master = @variants.find {|v| v.is_master}
        if master.respond_to?(method)
            master.send(method, *args)
        end
    end

end

class Variant 
    attr_accessor :price, :sku, :is_master
    def initialize(data={})
      @price = data[:price]
      @sku = data[:sku]
      @is_master = data[:is_master] || false
    end
end

variant = Variant.new(price: 1000, sku: "BX")
variant2 = Variant.new(price: 1000, sku: "B2")

prod = Product.new(3000, "MASTER")
prod.add_variant(variant)
prod.add_variant(variant2)

puts prod.variants.first.price # 3000 // price of the master
puts prod.variants.last.sku  # B2 // sku of the third, last variant
puts prod.price #  3000 // price of the master