useOptimistic is highly ineffective for updating line items

[sorenhoyer]

I'm not sure why this has not been mentioned yet:

• add an item to the cart
• open the cart
• increment the quantity count by clicking as fast as possible 50 times in a row
• try to click outside the cart and navigate to another page

It'll take a while before navigation occurs (while the server actions is being processed).

useOptimistic is not great for incrementing quantity, as you can't easily debounce server actions as far as I know. Meaning if you click to increment quantity e.g. 50 times, you'll queue and execute 50 server actions after each other.

That can be reduced to just 1 server action call if you do it manually with useState and debounce of e.g. 300-400ms.