// Import directly from source files instead of barrel files. Apply when using libraries like lucide-react, @mui/material, or @radix-ui/react-* to reduce bundle size and improve dev boot time.
| name | bundle-barrel-imports |
| description | Import directly from source files instead of barrel files. Apply when using libraries like lucide-react, @mui/material, or @radix-ui/react-* to reduce bundle size and improve dev boot time. |
Import directly from source files instead of barrel files to avoid loading thousands of unused modules. Barrel files are entry points that re-export multiple modules (e.g., index.js that does export * from './module').
Popular icon and component libraries can have up to 10,000 re-exports in their entry file. For many React packages, it takes 200-800ms just to import them, affecting both development speed and production cold starts.
Why tree-shaking doesn't help: When a library is marked as external (not bundled), the bundler can't optimize it. If you bundle it to enable tree-shaking, builds become substantially slower analyzing the entire module graph.
Incorrect (imports entire library):
import { Check, X, Menu } from 'lucide-react'
// Loads 1,583 modules, takes ~2.8s extra in dev
// Runtime cost: 200-800ms on every cold start
import { Button, TextField } from '@mui/material'
// Loads 2,225 modules, takes ~4.2s extra in dev
Correct (imports only what you need):
import Check from 'lucide-react/dist/esm/icons/check'
import X from 'lucide-react/dist/esm/icons/x'
import Menu from 'lucide-react/dist/esm/icons/menu'
// Loads only 3 modules (~2KB vs ~1MB)
import Button from '@mui/material/Button'
import TextField from '@mui/material/TextField'
// Loads only what you use
Alternative (Next.js 13.5+):
// next.config.js - use optimizePackageImports
module.exports = {
experimental: {
optimizePackageImports: ['lucide-react', '@mui/material']
}
}
// Then you can keep the ergonomic barrel imports:
import { Check, X, Menu } from 'lucide-react'
// Automatically transformed to direct imports at build time
Direct imports provide 15-70% faster dev boot, 28% faster builds, 40% faster cold starts, and significantly faster HMR.
Libraries commonly affected: lucide-react, @mui/material, @mui/icons-material, @tabler/icons-react, react-icons, @headlessui/react, @radix-ui/react-*, lodash, ramda, date-fns, rxjs, react-use.
Reference: How we optimized package imports in Next.js
Create pixelated borders, shadows, and effects for 8-bit retro components. Apply when building 8-bit styled UI components that need authentic pixel art aesthetics.
Create documentation with gaming-specific examples, retro styling, and 8-bit terminology. Apply when documenting gaming blocks, RPG components, or retro-styled UI elements.
Optimize 8-bit animations for smooth performance. Apply when creating animated pixel art, game UI effects, or any retro-styled animations.
Use next/dynamic for lazy-loading heavy components. Apply when importing large components like editors, charts, or rich text editors that aren't needed on initial render.
Best practices for wrapping shadcn/ui components. Apply when creating 8-bit styled variants of existing shadcn/ui components.
Create component documentation with installation, usage examples, and preview sections. Apply when documenting 8-bit components with proper structure and examples.