React @react.dev · Nov 1 did you know that you can conditionally exit an effect? this is useful if you want a subscription to only stay active while some condition is true, and to stay removed while that condition is false. a bit mindbending, but so it is with react!
403 likes 11 replies
Replies
Just don't return null. Undefined works nicely.
Programmers delight
Copilot actually suggested this pattern to me and I have used it a few times since
doesn't play well with this lint rule though eslint.org/docs/latest/... we had to drop it from our lint config especially because of those kind of useEffecys but tbh I don't miss it 🙏
Huh didn't realize you could just bail out of a useEffect interesting.
Shared a recent blog article on this from @robinmalfait.com in the newsletter: robinmalfait.com/blog/conditi...
It is a callback *function*. It is just a function. `return` is how you exit a function. Not sure that this is "mind bending". And this is how JavaScript works, not so much about React.
i do this so much... "guard clauses" are goat