`react-doctor/no-effect-wrapper-discards-callback-cleanup-return`

Effect wrapper discards forwarded cleanup return

Category: Bugs
Severity: warn
Source: oxlint-plugin-react-doctor
Framework: global
Enabled when: react
Default: Enabled

Validate the diagnostic

Confirm the reported code matches this rule before you edit it.

Confirm the reported code matches react-doctor/no-effect-wrapper-discards-callback-cleanup-return. Compare it with the Before example and verify the same API, framework, and execution context. Treat it as a false positive only when one of those conditions differs.

Compare the code

The corrected pattern shows a focused way to address the diagnostic.

Reported pattern

const useUpdateEffect = (effect: EffectCallback, deps?: DependencyList) => {
  const mounted = useRef(false);
  useEffect(() => {
    mounted.current ? effect() : (mounted.current = true);
  }, deps);
};

Corrected pattern

const useUpdateEffect = (effect: EffectCallback, deps?: DependencyList) => {
  const mounted = useRef(false);
  useEffect(() => {
    if (mounted.current) return effect();
    mounted.current = true;
  }, deps);
};

How to fix

Use the corrected pattern as a reference. Preserve behavior that the rule does not require you to change.

Copyable fix prompt

Copy this self-contained prompt into your coding agent after you confirm the diagnostic.

Fix every confirmed react-doctor/no-effect-wrapper-discards-callback-cleanup-return diagnostic in the current repository. Required change: - A custom effect wrapper must return its forwarded EffectCallback's result so React can run the cleanup. Calling it as a bare fn() instead of return fn() silently drops the cleanup, leaking every subscription/timer/listener it set up.

Reference transformation:Before:

const useUpdateEffect = (effect: EffectCallback, deps?: DependencyList) => {
  const mounted = useRef(false);
  useEffect(() => {
    mounted.current ? effect() : (mounted.current = true);
  }, deps);
};

After:

const useUpdateEffect = (effect: EffectCallback, deps?: DependencyList) => {
  const mounted = useRef(false);
  useEffect(() => {
    if (mounted.current) return effect();
    mounted.current = true;
  }, deps);
};

Constraints: - Confirm the reported code matches the Before pattern. - Make the smallest change that fixes the root cause. - Preserve behavior and interfaces unrelated to this diagnostic. - Reuse existing project components, utilities, and conventions. - Do not introduce render-phase side effects, render-phase state updates, or Hooks rule violations. - Adapt identifiers and framework details instead of copying blindly. - Do not disable the rule or suppress matching code. - Confirm this rule is enabled for the project: react. Verification: - Run focused tests for the changed behavior. - Run React Doctor and confirm this diagnostic no longer appears. - Report the files changed and any checks you could not run.

More Bugs rules from the rules reference:

react-doctor/no-enter-submit-without-ime-composition-guard: Enter submit without IME composition guard
react-doctor/no-event-handler: Disallow using state and an effect as an event handler.
react-doctor/no-event-trigger-state: Delete the trigger state (`useState(null)` plus the `useEffect` that watches it) and call the side-effect (`post(...)` / `navigate(...)` / `track(...)`) directly inside the event handler that previously called the setter. State should not exist purely to schedule effect runs
react-doctor/no-fetch-in-effect: Use `useQuery()` from @tanstack/react-query, `useSWR()`, or fetch in a Server Component instead
react-doctor/no-fetch-response-used-without-status-check: fetch Response consumed without status check

react-doctor/no-effect-wrapper-discards-callback-cleanup-return