dont-do

Don't Do These Things

Next.js

• Prefer use pages router (use app router)
• Don't nest server components in client components
• Don't use use client in server components
• Don't fetch data with server actions
• Don't mix client and server code
• Don't use getStaticProps or getServerSideProps
• Don't use router.push in server components

React

• Don't use class components
• Don't use default exports
• Don't use React.FC type
• Don't use inline styles (use Tailwind)
• Don't use useState when useReducer is clearer
• Don't mutate state directly
• Don't use indexes as keys

TypeScript

• Don't use any type
• Don't disable TypeScript checks
• Don't use @ts-ignore
• Don't use non-null assertion operator
• Don't use Object type
• Don't use Function type
• Don't use {} as a type

State Management

• Don't use global state for local concerns
• Don't prop drill more than 2 levels
• Don't mutate context values directly
• Don't use Redux (use context + reducers)
• Don't store derived state
• Don't store server state client-side
• Don't duplicate state

API

• Don't expose internal APIs publicly
• Don't handle errors silently
• Don't return raw error messages
• Don't trust client-side data
• Don't expose sensitive information
• Don't make unnecessary API calls
• Don't ignore API errors

Security

• Don't store secrets in code
• Don't use eval() or new Function()
• Don't trust user input
• Don't expose stack traces
• Don't store sensitive data client-side
• Don't use innerHTML
• Don't disable security headers

Performance

• Don't bundle unused code
• Don't load unnecessary resources
• Don't block the main thread
• Don't ignore memory leaks
• Don't skip code splitting
• Don't ignore performance metrics
• Don't render unnecessary components

Database

• Don't use raw SQL queries
• Don't store passwords in plain text
• Don't use boolean fields (use dates)
• Don't ignore database indexes
• Don't leak connection pools
• Don't ignore transaction boundaries
• Don't store large blobs