Its now working with STI as item_for search for Parent class

[imsinu9]

def item_for(object)
  shopping_cart_items.where(:item => object).first
end

This returns parent object and if child object is passed as object it returns nil which makes remove call not to execute.

To work with STI

I have to override this method in my model which act like Shopping Cart.

• [ ] We should rollback #13.