useEffectEvent for Stable Callback Refs
Access latest values in callbacks without adding them to dependency arrays. Prevents effect re-runs while avoiding stale closures.
Incorrect (effect re-runs on every callback change):
tsx
function SearchInput({ onSearch }: { onSearch: (q: string) => void }) {
const [query, setQuery] = useState('');
useEffect(() => {
const timeout = setTimeout(() => onSearch(query), 300);
return () => clearTimeout(timeout);
}, [query, onSearch]);
}
Correct (using React's useEffectEvent):
tsx
import { useEffectEvent } from 'react';
function SearchInput({ onSearch }: { onSearch: (q: string) => void }) {
const [query, setQuery] = useState('');
const onSearchEvent = useEffectEvent(onSearch);
useEffect(() => {
const timeout = setTimeout(() => onSearchEvent(query), 300);
return () => clearTimeout(timeout);
}, [query]);
}