# `react-doctor/no-impure-state-updater`

State updater has side effects

- **Category:** Bugs
- **Severity:** error
- **Source:** oxlint-plugin-react-doctor
- **Framework:** global
- **Enabled when:** react

## Validation prompt

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

Confirm the reported code matches State updater has side effects. Check the framework context and diagnostic message before suppressing it.

## Fix prompt

Use this once validation confirms the diagnostic is real.

Keep state updater callbacks pure and return only the next state. Move notifications, storage, timers, ref writes, and other external work into the event or effect that queues the update.