react-doctor/no-effect-chain

Compute as much as possible during render (e.g. `const isGameOver = round > 5`) and write all related state inside the event handler that originally fires the chain. Each effect link adds an extra render and makes the code rigid as requirements evolve

• Category: State & Effects
• Severity: warn
• Source: oxlint-plugin-react-doctor
• Framework: global
• Enabled when: always

Validation prompt

Use this to decide whether a fired diagnostic is real or a false positive.

Fires on a useEffect B whose deps include a state X synchronously set by another sibling useEffect A in the same component, where neither effect is 'external sync' — neither returns a function-shaped cleanup nor calls fetch / setInterval / observer constructors / assigns to a ref's .current. Setters nested inside .then or setTimeout do NOT count toward A's writes. False positive: a deliberate two-phase state machine where the next phase must wait for a render commit (rare).

Fix prompt

Use this once validation confirms the diagnostic is real.

Compute as much as possible during render (const isGameOver = round > 5) and move ALL related state writes into the one event handler that originally fires the chain — a single useReducer dispatch can set every chained value at once. Reserve useEffect for synchronizing with truly external systems. See https://react.dev/learn/you-might-not-need-an-effect#chains-of-computations

Related rules

More State & Effects rules from the rules reference:

• react-doctor/no-effect-event-handler: Move the conditional logic into onClick, onChange, or onSubmit handlers directly
• react-doctor/no-effect-event-in-deps: Call the useEffectEvent callback inside the effect body without listing it; its identity is intentionally unstable
• react-doctor/no-effect-with-fresh-deps: Move the constructed value into the hook body and depend on its primitive inputs, or memoize it with useMemo/useCallback so its reference is stable.
• 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