JS Bun Majo

JavaScript/TypeScript with Bun

Goal: Ensure Bun is used as the runtime, tooling, and package manager for all JavaScript and TypeScript development, completely replacing Node.js and npm.

When to Use This Skill

• Initializing a new JS/TS project
• Migrating from Node.js/npm to Bun
• Running JavaScript or TypeScript code
• Installing packages or dependencies
• Building or bundling JS/TS projects
• Writing scripts in package.json equivalents

When NOT to Use This Skill

• Project explicitly requires Node.js runtime (e.g., specific Node APIs)
• Legacy project with npm-specific configurations that can't migrate
• Working with Deno instead of Bun

Process

1. Check for existing Node/npm usage - Look for package-lock.json, node_modules, npm scripts
2. Install Bun if not present - Use system package manager or curl -fsSL https://bun.sh/install | bash
3. Initialize with Bun - Use bun init instead of npm init
4. Install dependencies - Use bun install instead of npm install
5. Run scripts - Use bun run <script> instead of npm run
6. Execute files - Use bun <file> instead of node <file>
7. Add dependencies - Use bun add <pkg> instead of npm install <pkg>
8. Update AGENTS.md - Document Bun usage for the project

Constraints

• ALWAYS prefer Bun over Node.js and npm in all circumstances
• NEVER use npm commands (npm install, npm run, npx) when Bun alternatives exist
• NEVER create package-lock.json - Bun uses bun.lockb instead
• Check package.json exists before assuming Bun is initialized
• If uncertain on Bun commands, use bun --help or command line for assistance

Use Bun as the runtime, tooling, and package manager in lieu of Node and npm.

This applies to both JavaScript and TypeScript projects.

If uncertain on how to invoke Bun commands, use the command line for help.

Testing Skills

• Verify Bun is installed: bun --version
• Test script execution: bun run <script-name>
• Check lockfile: bun.lockb should exist, not package-lock.json
• Ensure no npm commands in documentation or scripts

Integration

This skill extends dev-standards-majo. Always ensure dev-standards-majo is loaded for:

• AGENTS.md maintenance
• Universal code principles
• Documentation policies

Works alongside:

• git-majo — For committing JavaScript/TypeScript changes
• writing-docs-majo — For writing JavaScript/TypeScript documentation