tsbundle/readme.hints.md

tsbundle Hints and Findings

Bundler Architecture

• tsbundle uses a child process architecture where each bundler runs in a separate process
• Configuration is passed via environment variables as JSON (IEnvTransportOptions)
• The main class TsBundle spawns child processes using smartspawn.ThreadSimple

Bundler Implementations

• esbuild (default): Fully implemented, production ready
• rolldown: Implemented and working (beta), produces smaller bundles than esbuild
• rollup: Empty module directory exists but not implemented
• parcel: Empty module directory exists but not implemented

Adding New Bundlers

To add a new bundler, you need:

1. Update ICliOptions interface to include the bundler name
2. Add case in getBundlerPath() switch statement
3. Create mod_<bundler>/ directory with:
   • plugins.ts: Import and re-export the bundler
   • index.child.ts: Implement TsBundleProcess class with buildTest() and buildProduction()
4. Add bundler to package.json dependencies

Rolldown Specific Notes

• Rolldown is in beta (v1.0.0-beta.18) but working well
• API: Use rolldown() function directly, not rolldown.rolldown()
• Output options go in the write() method, not the initial config
• Produces smaller minified bundles than esbuild (1.5K vs 2.2K in tests)
• Supports TypeScript via resolve.tsconfigFilename

CLI Usage

• Default bundler: tsbundle
• Specify bundler: tsbundle --bundler=rolldown
• Production mode: tsbundle --production
• Combined: tsbundle --bundler=rolldown --production

Known Issues

• esbuild recently had splitting and tree-shaking disabled due to issues
• The README still mentions "a bundler using rollup" but uses esbuild by default