React & Next.js Standards

Component Architecture

• Prefer function components with hooks
• Keep components small and focused (single responsibility)
• Separate container (logic) from presentational (UI) components
• Use composition over prop drilling
• Co-locate related files (component, styles, tests, types)

Naming Conventions

• Components: PascalCase (UserProfile.tsx)
• Hooks: camelCase with use prefix (useAuth)
• Event handlers: handle prefix (handleClick)
• Boolean props: is, has, should prefixes

Hooks Best Practices

• Follow rules of hooks (top-level, React functions only)
• Extract custom hooks for reusable logic
• Use useMemo/useCallback for expensive computations or stable references
• Avoid premature memoization - measure first
• Keep dependency arrays accurate and minimal

State Management

• Start with local state (useState)
• Lift state only when necessary
• Use Context for truly global state (theme, auth)
• Consider Zustand/Jotai for complex client state
• Server state: React Query/SWR/TanStack Query

Next.js Patterns

• Prefer Server Components by default
• Use "use client" only when necessary (interactivity, hooks, browser APIs)
• Leverage loading.tsx and error.tsx for loading/error states
• Use Route Handlers for API endpoints
• Implement proper metadata for SEO

Performance

• Lazy load heavy components with React.lazy or next/dynamic
• Optimize images with next/image
• Use Suspense boundaries strategically
• Avoid inline object/array literals in JSX props
• Profile with React DevTools before optimizing

Forms & Validation

• Use controlled components or React Hook Form
• Validate with Zod for type-safe schemas
• Show validation errors inline
• Disable submit during loading
• Handle server errors gracefully

Testing

• Test behavior, not implementation
• Use React Testing Library
• Test user interactions and outcomes
• Mock external dependencies
• Write integration tests for critical flows