build

Builds the application for production.

Usage

bun ereo build [options]

Or via package.json:

{
  "scripts": {
    "build": "ereo build"
  }
}

bun run build

Options

Option	Description	Default
--outDir	Output directory	.ereo
--minify	Minify output (true or false)	true
--sourcemap	Generate source maps (true or false)	true

Examples

Basic Build

# Build with defaults (output to .ereo/, minified, with sourcemaps)
bun ereo build

# Custom output directory
bun ereo build --outDir dist

# Disable source maps
bun ereo build --sourcemap=false

# Disable minification (for debugging)
bun ereo build --minify=false

# Production build with all optimizations
bun ereo build --outDir dist --minify --sourcemap=false

Output Structure

.ereo/
├── server/
│   └── index.js         # Server bundle
├── client/
│   ├── index.js         # Client entry
│   ├── islands/         # Island bundles
│   │   ├── Counter.js
│   │   └── SearchBox.js
│   └── chunks/          # Shared chunks
│       ├── react.js
│       └── vendor.js
└── static/
    ├── styles.css       # Compiled CSS
    └── public/          # Static assets

Build Process

1. Type checking - Validates TypeScript
2. Route discovery - Finds all routes
3. Server bundle - Compiles server code
4. Client bundle - Compiles client code
5. Island extraction - Creates island bundles
6. Asset processing - Optimizes static assets
7. Manifest generation - Creates asset manifest

Configuration

Configure build in ereo.config.ts:

import { defineConfig } from '@ereo/core'

export default defineConfig({
  build: {
    // Deployment target
    target: 'bun', // 'bun' | 'node' | 'cloudflare' | 'deno'

    // Output directory
    outDir: '.ereo',

    // Minification
    minify: true,

    // Source maps
    sourcemap: true, // true | false

    // Code splitting
    splitting: true,

    // External packages (not bundled)
    external: ['sharp', 'sqlite3']
  }
})

Environment Variables

Build-time environment:

# Production build
NODE_ENV=production bun ereo build

# Custom environment
NODE_ENV=staging bun ereo build

Environment files loaded:

1. .env
2. .env.local
3. .env.production
4. .env.production.local

Static Generation

For SSG routes, pages are pre-rendered:

// routes/posts/[slug].tsx
export const config = {
  render: 'ssg'
}

export async function getStaticPaths() {
  const posts = await db.posts.findMany()
  return posts.map(post => ({
    params: { slug: post.slug }
  }))
}

Build output includes static HTML:

dist/
└── static/
    └── posts/
        ├── hello-world.html
        ├── getting-started.html
        └── advanced-guide.html

Programmatic Usage

import { build } from '@ereo/cli'

await build({
  outDir: 'dist',
  minify: true,
  sourcemap: false
})

Build Analysis

Bundle Size

After build, check bundle sizes:

ls -lh dist/client/

Visualization

Generate bundle analysis:

bun ereo build --analyze

Opens interactive bundle visualization in browser.

Optimization Tips

Code Splitting

EreoJS automatically splits:

• Each route into separate chunks
• Each island into separate bundles
• Shared dependencies into common chunks

Tree Shaking

Unused exports are removed. Ensure:

• Use ES modules (import/export)
• Avoid side effects in modules
• Mark packages as side-effect-free in package.json

External Dependencies

For server-only packages:

// ereo.config.ts
export default defineConfig({
  build: {
    external: ['sharp', 'bcrypt', 'sqlite3']
  }
})

Troubleshooting

Build Errors

# Verbose output
DEBUG=ereo:* bun ereo build

# Skip type checking
bun ereo build --skipTypeCheck

Large Bundle Size

1. Check for unnecessary dependencies
2. Use dynamic imports for large modules
3. Analyze bundle with --analyze

Memory Issues

For large projects:

# Increase memory limit
NODE_OPTIONS="--max-old-space-size=8192" bun ereo build

Related

• dev
• start
• Deployment