.cursorrules

# react-simplikit Cursor Rules

> Full coding standards with examples: see AGENTS.md

## Project

React hooks/components library. Monorepo: `packages/core` + `packages/mobile`.

## Architecture

Unidirectional layers: `components → hooks → utils → _internal`
Core and mobile are independent packages. No cross-package dependencies.

## Code Style

- `type` over `interface` for type aliases
- Named functions in useEffect: `useEffect(function handleResize() { ... }, [])`
- Named exports only, no default exports
- No `any` — strict TypeScript
- `.ts`/`.tsx` extensions in source imports (tsup converts to `.js`)
- No implicit boolean coercion: `if (value)` → `if (value != null)` (enforced by `strict-boolean-expressions`)
- Nullish checks: `== null` for both null and undefined, `!== undefined` only when distinction matters
- Zero runtime dependencies
- Always return cleanup in useEffect to remove listeners
- Early returns (guard clauses) over nested if-else blocks
- Function declarations use `function` keyword, not arrow: `function toggle(state: boolean) { return !state; }`
- Short inline callbacks (map, filter args) are OK with arrow functions