Using Bun

When to use this skill

• When the user explicitly mentions “Bun”.
• When the user wants to run TypeScript files directly without compilation.
• When the user wants faster package installation (replacing npm/yarn).
• When the user needs a fast test runner or bundler.
• When the user wants to use native APIs like Bun.serve, Bun.file, Bun.write.

Workflow

1. Verify Installation: Check if Bun is available.
   • bun --version
2. Initialize Project (if new):
   • bun init
3. Manage Dependencies:
   • Install: bun install (replaces npm install)
   • Add: bun add <package> (replaces npm install <package>)
   • Remove: bun remove <package>
4. Run Scripts/Files:
   • Run file: bun <file.ts/js> (e.g., bun index.ts)
   • Run script: bun run <script-name>
   • Watch mode: bun --hot <file.ts>
5. Testing:
   • Run tests: bun test
6. Building:
   • Bundle: bun build ./entry.ts --outdir ./out

Instructions

• Runtime: Bun runs .ts and .tsx files directly. No tsc needed for execution.
• Package Manager: Use bun install instead of npm install. It reads package.json and writes to bun.lockb (binary lockfile).
• Test Runner: bun test is a drop-in replacement for Jest. It supports describe, test, expect automatically.
• Environment Variables: Bun reads .env files automatically. Access via process.env or Bun.env.
• Shell: Use Bun.$ for cross-platform shell scripting in JavaScript files.

Resources

• Bun Documentation
• Bun API