Update state on sort

[bullbates]

I'm trying to create a sortable list where each item is prepended with the number of the item in the list. This is all fine and working however while the user drags the item around, the numbers are not in the correct order. I got it to work by updating the state and thereby rerendering the entire list in the handleDragMove function however this feels like an incorrect solution and will likely run into performance issues. Indeed, in my testing, it does seem to mess up the functionality with the dragged item acting more chaotically and jerking around in the list.

Is there a better way to achieve this?