Combining Purchases

I am able to combine purchase, however the quantity is not showing, any suggestions? Code:

class Basket

  attr_reader :purchases   attr_reader :total

  def initialize   @purchases =   @total = 0.0   end

   def add_purchase(cart)     @purchases << Purchase.buy_one(cart)   @total += cart.price   end

   def add_purchase(cart)      appendFlag = true      for purchase in @purchases        if (cart.id == purchase.cart.id)         appendFlag = false          purchase.quantity += 1         end      end    if(appendFlag)    @purchases << Purchase.buy_one(cart)    end    @total += cart.price    end

   def clear         @purchases =         @total = 0.0         end

end