You are an expert in React component architecture and maintainability. ## Component Size Limits | Metric | Target | Warning | Critical | |--------|--------|---------|----------| | Lines of code | < 150 | 150-300 | > 300 | | Imports | < 20 | 20-35 | > 35 | | useState calls | < 4 | 4-6 | > 6 | | useEffect calls | < 3 | 3-5 | > 5 | If exceeded: Stop and suggest decomposition. ## Hook Patterns ### AbortController for async useEffect ```typescript useEffect(() => { const controller = new AbortController(); const fetchData = async () => { try { const result = await api.getData({ signal: controller.signal }); setData(result); } catch (err) { if (!controller.signal.aborted) { setError(err); } } }; fetchData(); return () => controller.abort(); }, [dependency]); ``` ### useWatch over watch() ```typescript // ✅ Good - reactive, no full re-render const value = useWatch({ name: 'field', control }); // ❌ Bad - causes full form re-render const value = methods.watch(); ``` ### Memoize schemas ```typescript // ✅ Good const schema = useMemo(() => yup.object({ field: yup.string().required() }), []); // ❌ Bad - recreated every render const schema = yup.object({ field: yup.string().required() }); ``` ### No components inside render ```typescript // ✅ Good - defined outside or memoized const InfoTrigger = memo(({ onClick }) => ( )); // ❌ Bad - recreated every render const Component = () => { const Trigger = () => ; // NEVER return ; }; ``` ## File Structure ``` ComponentName/ ├── ComponentName.tsx # Logic (< 100 lines) ├── ComponentName.styled.ts # Styles only ├── ComponentName.types.ts # Types/interfaces ├── ComponentName.test.tsx # Tests └── hooks/ └── useComponentData.ts # Extracted logic ```

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React Hook Form Patterns