Setup React Rules

Setup React Rules

PostToolUse hooks on Edit/Write (auto-skip component library dirs):

Enforced Rules

HTML/Components: ban raw HTML elements (use @/components/ui/), ban inline style={{}} (use Tailwind), ban icon inside AlertTitle (use icon prop), require handler on buttons (onClick/asChild/type="submit"/disabled)

TypeScript: ban as any, as Record<string,any>, @ts-ignore, @ts-expect-error

Security: ban dangerouslySetInnerHTML, eval(), new Function(), .innerHTML = (XSS/OWASP A03)

Performance: ban barrel imports (use direct paths), ban missing { passive: true } on scroll/touch/wheel, ban static import of heavy deps (chart.js/d3/three.js/pdf-lib -- use React.lazy())

Styling: ban raw hex/rgb in className (use design tokens), ban !important, ban outline: none (use focus-visible), ban visual overrides on registry components (use variant prop)

Navigation: ban onClick + navigate() (use <Button asChild><Link>), require aria-label on icon-only buttons

React Compiler: ban manual useMemo/useCallback/React.memo, ban class components

Protobuf: enforce create() wrapper for message spreads (v2)

Opt-in Rules

• REACT_RULES_BAN_USEEFFECT=1: ban useEffect/useLayoutEffect/useInsertionEffect. Escape: // allow: useEffect [reason]
• REACT_RULES_BAN_TYPE_ASSERTIONS=1: ban as X (allow as const). Force type guards/generics/schema validation.

Soft Guidance (Claude-enforced, not hooks)

• Named useEffect functions describe purpose. No name without "and"? Split.
• useSyncExternalStore for browser API subscriptions (navigator.onLine, matchMedia, scroll)
• Form-level validate cross-field validation (react-hook-form v7.72+)

Functional Programming (Claude-enforced)

• Pure render -- no side effects in component body
• Immutable state -- spread/filter/map, never mutate
• Derive don't sync -- useMemo not useState+useEffect
• useReducer for 3+ interrelated useState
• Extract data transforms to named pure functions
• Discriminated unions for variant prop types
• Generic <T> for reusable typed components

See REFERENCE.md for patterns + examples.

Steps

1. Copy scripts/react-rules-check.sh + scripts/fp-check.sh + scripts/tailwind-check.sh + scripts/_hook-lib.sh -> .claude/hooks/. chmod +x.
2. Add to PostToolUse (Edit|Write) in .claude/settings.json.
3. Optional: codex-compat for .codex/hooks.json.

Verify

• Block raw HTML, as any, @ts-ignore in TSX
• Auto-skip component library dirs
• Opt-in rules work when env vars set