@pegasusheavy/ngx-bun

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High-performance SSR/SSG adapter for Angular 19+ using Bun's built-in server

Features • Installation • Quick Start • Configuration • API • Prerendering

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Features

• 🚀 Blazing Fast - Leverages Bun's high-performance HTTP server and runtime
• 📦 Full SSR Support - Complete server-side rendering for Angular 19+
• 🏗️ SSG/Prerendering - Generate static HTML files at build time
• 🔄 Automatic Hydration - Seamless client-side hydration
• 📁 Static File Serving - Optimized static asset serving with compression
• 💾 Built-in Caching - LRU cache for rendered pages
• 🛠️ Angular CLI Integration - Schematics for easy setup with ng add
• 🔧 Custom Builders - Angular CLI builders for development and production

Requirements

• Angular 19.0.0 or higher
• Bun 1.0.0 or higher
• Node.js 20.0.0 or higher (for Angular CLI)

Installation

Using Angular CLI (Recommended)

ng add @pegasusheavy/ngx-bun

This will:

1. Install the package and dependencies
2. Generate the server file (server.ts)
3. Create server-side configuration files
4. Update angular.json with SSR targets
5. Add npm scripts for development and production

Manual Installation

# Install the package
pnpm add @pegasusheavy/ngx-bun

# Install peer dependencies
pnpm add @angular/ssr @angular/platform-server

Quick Start

1. Add SSR to your Angular project

ng add @pegasusheavy/ngx-bun

2. Start the development server

pnpm dev:ssr

3. Build for production

pnpm build:ssr

4. Serve production build

pnpm serve:ssr

Configuration

Server Configuration

The generated server.ts file can be customized:

import { createBunServer, createBunAngularEngine } from '@pegasusheavy/ngx-bun';

const engine = createBunAngularEngine({
  bootstrap: () => import('./src/main.server'),
  browserDistFolder: './dist/my-app/browser',

  // Cache configuration
  enableCache: true,
  maxCacheSize: 100,
  cacheTtl: 300_000, // 5 minutes
});

createBunServer({
  engine,
  port: 4000,
  hostname: 'localhost',

  // Enable request logging
  logging: true,

  // Routes to skip SSR (client-only)
  clientOnlyRoutes: ['/admin/*'],

  // Development mode
  development: process.env.NODE_ENV !== 'production',
});

Route Rendering Configuration

Configure how each route is rendered in app.routes.server.ts:

import { RenderMode, ServerRoute } from '@angular/ssr';

export const serverRoutes: ServerRoute[] = [
  // Client-side only (no SSR)
  { path: 'admin/**', renderMode: RenderMode.Client },

  // Prerendered at build time (SSG)
  { path: 'about', renderMode: RenderMode.Prerender },
  { path: 'blog/:slug', renderMode: RenderMode.Prerender },

  // Server-side rendered on each request (SSR)
  { path: '**', renderMode: RenderMode.Server },
];

Angular.json Targets

The schematic adds these targets to your angular.json:

{
  "serve-ssr": {
    "builder": "@pegasusheavy/ngx-bun:serve",
    "options": {
      "browserTarget": "my-app:build",
      "port": 4000
    }
  },
  "prerender": {
    "builder": "@pegasusheavy/ngx-bun:prerender",
    "options": {
      "browserTarget": "my-app:build:production",
      "routes": ["/", "/about", "/contact"]
    }
  }
}

API

createBunAngularEngine(options)

Creates the Angular SSR engine.

interface BunAngularEngineOptions {
  // Angular bootstrap function
  bootstrap: () => Promise<ApplicationRef>;

  // Path to browser distribution
  browserDistFolder: string;

  // Path to server distribution (optional)
  serverDistFolder?: string;

  // Custom index.html path (optional)
  indexHtml?: string;

  // Additional providers (optional)
  providers?: Provider[];

  // Enable render caching (default: true)
  enableCache?: boolean;

  // Max cache entries (default: 100)
  maxCacheSize?: number;

  // Cache TTL in ms (default: 300000)
  cacheTtl?: number;
}

createBunServer(options)

Creates and starts the Bun server.

interface BunServerOptions {
  // The Angular engine instance
  engine: BunAngularEngine;

  // Server port (default: 4000)
  port?: number;

  // Server hostname (default: 'localhost')
  hostname?: string;

  // Enable static file serving (default: true)
  serveStatic?: boolean;

  // Static files directory
  staticDir?: string;

  // Development mode (default: false)
  development?: boolean;

  // Enable request logging (default: false)
  logging?: boolean;

  // Routes to skip SSR
  clientOnlyRoutes?: string[];

  // TLS configuration for HTTPS
  tls?: { cert: string; key: string };

  // Server start callback
  onStart?: (server: Server) => void;
}

createRequestHandler(options)

Creates a request handler for custom server setups.

import { createRequestHandler } from '@pegasusheavy/ngx-bun';

const handler = createRequestHandler({
  engine,
  staticHandler,
  logging: true,
});

// Use with Bun.serve directly
Bun.serve({
  fetch: handler,
  port: 4000,
});

createStaticFileHandler(options)

Creates a static file handler with caching and compression.

interface StaticFileOptions {
  // Root directory for static files
  root: string;

  // Index file name (default: 'index.html')
  index?: string;

  // Enable compression (default: true)
  compression?: boolean;

  // Custom MIME types
  mimeTypes?: Record<string, string>;

  // Cache control header
  cacheControl?: string | ((path: string) => string);
}

Prerendering (SSG)

Using Angular CLI

ng run my-app:prerender

Programmatic API

import { prerenderRoutes } from '@pegasusheavy/ngx-bun/prerender';

const result = await prerenderRoutes({
  engineOptions: {
    bootstrap,
    browserDistFolder: './dist/browser',
  },
  routes: ['/', '/about', '/blog/post-1', '/blog/post-2'],
  outputDir: './dist/prerendered',
  concurrency: 5,
  generateSitemap: true,
  baseUrl: 'https://example.com',
  onProgress: (completed, total, path) => {
    console.log(`[${completed}/${total}] ${path}`);
  },
});

console.log(`Prerendered ${result.success} routes in ${result.totalTime}ms`);

Dynamic Route Parameters

const result = await prerenderRoutes({
  routes: [
    '/',
    '/about',
    {
      path: '/blog/:slug',
      getParams: async () => {
        // Fetch slugs from CMS or database
        const posts = await fetchBlogPosts();
        return posts.map(post => ({ slug: post.slug }));
      },
    },
  ],
  // ...
});

Environment Variables

Variable	Description	Default
NODE_ENV	Environment mode	development
PORT	Server port	4000
HOST	Server hostname	localhost
BROWSER_DIST_FOLDER	Browser dist path	Auto-detected
SERVER_DIST_FOLDER	Server dist path	Auto-detected

Performance Tips

1. Enable caching in production for frequently accessed pages
2. Use prerendering for static content that doesn't change often
3. Set appropriate cache headers for static assets
4. Use clientOnlyRoutes for pages that don't benefit from SSR
5. Monitor render times using the X-Render-Time response header

Comparison with Express-based SSR

Feature	@pegasusheavy/ngx-bun	Express SSR
Cold Start	~50ms	~200ms
Memory Usage	Lower	Higher
Requests/sec	Higher	Lower
Bundle Size	Smaller	Larger
Native TypeScript	✅	❌

Troubleshooting

"Could not find index.html"

Make sure you've built the browser application first:

ng build

"Server bootstrap not found"

Ensure main.server.ts exists and exports a bootstrap function:

// src/main.server.ts
import { bootstrapApplication } from '@angular/platform-browser';
import { AppComponent } from './app/app.component';
import { config } from './app/app.config.server';

const bootstrap = () => bootstrapApplication(AppComponent, config);
export default bootstrap;

Hydration Mismatch Errors

Ensure your components handle server/browser differences:

import { isPlatformBrowser } from '@angular/common';
import { PLATFORM_ID, inject } from '@angular/core';

@Component({...})
export class MyComponent {
  private platformId = inject(PLATFORM_ID);

  ngOnInit() {
    if (isPlatformBrowser(this.platformId)) {
      // Browser-only code
    }
  }
}

Contributing

Contributions are welcome! Please read our Contributing Guide for details.

License

MIT © Pegasus Heavy Industries

Support

• 📖 Documentation
• 🐛 Issue Tracker
• 💬 Discussions

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Made with ❤️ for the Angular community