Bug: set-state-in-use-effect false negative when there are multiple instances #35291
Description
This code correctly produces a lint error:
function MyComponent() { const [loading, setLoading] = useState(false); useEffect(() => { setLoading(true); // ✅ ESLint correctly flags this (1 error) }, []); // commented out code... return null; }But this code does not:
function MyComponent() { const [loading, setLoading] = useState(false); useEffect(() => { setLoading(true); // ❌ BUG: Error no longer reported (should still be flagged!) }, []); const [firstName, setFirstName] = useState<string>(''); const [lastName, setLastName] = useState<string>(''); const [fullName, setFullName] = useState<string>(''); useEffect(() => { setFullName(`${firstName} ${lastName}`); // ❌ BUG: Also not reported }, [firstName, lastName]); return null; }React version: ^19.2.1
Steps To Reproduce
Created a minimal reproduction repo: https://github.com/roryabraham/set-state-in-effect-bug
The current behavior
In the second code snippet provided, no lint errors are thrown.
The expected behavior
Lint errors should be thrown for both setState calls in useEffect callbacks.