After introducting the CartItem object, the app blows up with :
NoMethodError in StoreController#add_to_cart
undefined method `product' for #<Product:0x2498b0c>
Application Trace | Framework Trace | Full Trace
This happens even after clearning sessions using rake. When I use a
different browser (Safari), it works. Looks like the session was
getting cached by Firefox. Hope this helps someone.