react-doctor/no-async-event-handler-without-reentry-guard

Async mutating handler without re-entry guard

Validation prompt

Confirm the detector match and collect the required evidence before deciding whether an edit is warranted.

Confirm the detector conditions for react-doctor/no-async-event-handler-without-reentry-guard in the reported code. The Before example is representative, not exhaustive. Verify the same API, framework, execution context, and any documented exceptions before editing.

Evidence boundary

The diagnostic proves only that the detector’s modeled source pattern matched. It does not prove runtime impact, product intent, rendered failure, or that one remediation is correct.

Establish the environment, repository policy, exceptions, and required rendered or runtime evidence before deciding the occurrence.

Record one outcome:

• Confirmed failure: The required evidence establishes the violation.
• Rejected: A documented exception or false-positive predicate applies.
• Needs evidence: Named evidence can still be collected.
• Unavailable: Required evidence cannot be collected in this run.
• Waived with evidence: An authorized, scoped exception applies to an established failure.
• Observation: The review records an optional tradeoff without claiming a defect.

A waiver records its scope, authority, evidence, and review condition. It is not a pass or false positive.

Default severity is registry metadata. Use the occurrence’s JSON severity after repository configuration when ordering real findings.

Review a candidate correction

Apply this candidate correction only after the required evidence confirms the risk.

Reported pattern

<button onClick={async () => { await save(); }}>Save</button>

Candidate corrected pattern

function SaveButton() {
  const [isSaving, setIsSaving] = useState(false);
  const isSavingRef = useRef(false);
  const handleSave = async () => {
    if (isSavingRef.current) return;
    isSavingRef.current = true;
    setIsSaving(true);
    try {
      await save();
    } finally {
      isSavingRef.current = false;
      setIsSaving(false);
    }
  };
  return (
    <button disabled={isSaving} onClick={handleSave}>
      {isSaving ? "Saving…" : "Save"}
    </button>
  );
}

Fix prompt

Apply this candidate correction only after the required evidence confirms the risk.

Block re-entry before the first await. Return when busy is true, or set the flag before entering try. Reset it in finally, and disable the control while the request runs.

Repository-wide copy prompt

Use this repository-wide prompt only after validating each occurrence. For one occurrence, use the guidance above.

<button onClick={async () => { await save(); }}>Save</button>

function SaveButton() {
  const [isSaving, setIsSaving] = useState(false);
  const isSavingRef = useRef(false);
  const handleSave = async () => {
    if (isSavingRef.current) return;
    isSavingRef.current = true;
    setIsSaving(true);
    try {
      await save();
    } finally {
      isSavingRef.current = false;
      setIsSaving(false);
    }
  };
  return (
    <button disabled={isSaving} onClick={handleSave}>
      {isSaving ? "Saving…" : "Save"}
    </button>
  );
}