 @cirosantilli/_file/nodejs/next/nodejs/next/ref-twice

This is a minimal reproducible example for the terrible problem of external effects applying twice to refs for effects that are not idempotent and thus blowup if applied twice.

The issue is currently discussed at: react.dev/learn/synchronizing-with-effects#step-3-add-cleanup-if-needed (archive) which says "you need to cleanup the thing yourself". web.archive.org/web/20240720100401/https://react.dev/learn/synchronizing-with-effects#subscribing-to-events is also says that for the specific case of addEventListener.

But that's annoying! Can't we just somehow tell if we applied twice or not to avoid having to implement a cleanup? What if a third party system does not provide a cleanup at all?

Is the correct solution to just just have a useEffect with empty dependency list? Seems to be good according to posts and to ESLint!

Tried to do a React only reproduction at: react/ref-twice.html.

Bibliography:

Ciro Santilli's questions: