Hello, hope somebody can help with this, it's a bit of an urgent issue to get fixed. 

The shopping cart form here (https://www.drkeithhammett.co.nz/shopping-cart) is allowing users to progress through to the Checking out stage without having selected a shipping option and I've just discovered that if the item was not assigned a tax value, this is also not preventing the progress. 

Where should I be seeing the validation in the cart files for this? In item.liquid or wrapper.liquid? There doesn't appear to be any that I can make out. There should be, shouldn't there? How can I fix this?