How to check if a $state has changed

[hyunbinseo]

I have an modal component library that receives an isOpen state from the user.

I would like to run a function everytime the isOpen state has changed.

$effect(() => {
  // This runs on initial mount as well
  console.log(Date.now(), isOpen);
});

Would there be a better solution than this?

// This works, but the boilerplate does not seem ideal:

let isOpened = isOpen;

$effect(() => {
  if (isOpened !== isOpen) console.log('Has toggled at', Date.now());
  isOpened = isOpen;
});