# react

Modern React (19+) patterns: hooks discipline, Suspense, transitions, no class components.

```bash
npx rulepack add react
```

## What it covers

- Function components only — no `class`, no `this`, no lifecycle methods; small functions with explicit prop types
- Hooks discipline: call at the top level, `useState`/`useReducer`/`useContext` chosen by need, and `useMemo`/`useCallback` only when profiling justifies it (React 19's compiler covers most cases)
- Async with `Suspense` boundaries and `use()` instead of bespoke loading flags, plus `startTransition` for non-urgent updates
- Refs via `useRef` for DOM nodes and mutable boxes; never read `.current` during render
- Anti-patterns to avoid: derived state in `useState`, mutating props, effects that only sync state to state, and index keys on reorderable lists

## Source

Rules align with the official React documentation: https://react.dev/learn

## License

MIT