# Claude Dev Suite Claude Dev Suite Bun > Bun - Quick Reference - Skill: `tomevault-io/claude-dev-suite-claude-dev-suite-bun` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/claude-dev-suite-claude-dev-suite-bun` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/claude-dev-suite-claude-dev-suite-bun/raw - Safety review: WARNING (external: skill-scanner WARNING, skillspector WARNING) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/claude-dev-suite-claude-dev-suite-bun --- # Bun - Quick Reference > **Deep Knowledge**: Use `mcp__documentation__fetch_docs` with technology: `bun` for comprehensive documentation. ## When to Use This Skill - Projects requiring high performance - Replacement for Node.js + npm + bundler - Fast test runner alternative to Vitest/Jest - Quick scripts with native TypeScript ## Setup ```bash # Install Bun curl -fsSL https://bun.sh/install | bash # Create project bun init # Run TypeScript directly (no compilation needed!) bun run index.ts # Run with watch mode bun --watch run index.ts ``` ## Package Manager ```bash # Install dependencies (faster than npm/pnpm) bun install # Add packages bun add express zod bun add -d typescript @types/node # Remove bun remove package-name # Update bun update # Run scripts bun run build bun run dev # Execute binary bunx prisma generate ``` ### Workspaces ```json // package.json { "workspaces": ["packages/*"] } ``` ```bash # Install all workspace deps bun install # Run in specific workspace bun run --filter @myorg/api build ``` ## Bundler ```typescript // Build for production await Bun.build({ entrypoints: ['./src/index.ts'], outdir: './dist', target: 'node', // 'browser' | 'bun' minify: true, sourcemap: 'external', splitting: true, // Code splitting format: 'esm', // 'cjs' | 'esm' }); // CLI bun build ./src/index.ts --outdir ./dist --minify ``` ### Build Config ```typescript // bunfig.toml alternative - build.ts const result = await Bun.build({ entrypoints: ['./src/index.tsx'], outdir: './dist', target: 'browser', minify: { whitespace: true, identifiers: true, syntax: true, }, define: { 'process.env.NODE_ENV': '"production"', }, external: ['react', 'react-dom'], loader: { '.png': 'file', '.svg': 'text', }, }); if (!result.success) { console.error('Build failed:', result.logs); process.exit(1); } ``` ## Test Runner ```typescript // math.test.ts import { describe, it, expect, beforeAll, mock } from 'bun:test'; describe('math', () => { it('adds numbers', () => { expect(1 + 2).toBe(3); }); it('handles async', async () => { const result = await fetchData(); expect(result).toBeDefined(); }); }); // Mocking const mockFn = mock(() => 42); mockFn(); expect(mockFn).toHaveBeenCalled(); // Module mocking mock.module('./config', () => ({ apiUrl: 'http://test.local', })); ``` ```bash # Run tests bun test # Watch mode bun test --watch # Coverage bun test --coverage # Filter bun test --filter "user" ``` ## HTTP Server ```typescript // Native Bun server (fastest) Bun.serve({ port: 3000, fetch(req) { const url = new URL(req.url); if (url.pathname === '/api/health') { return Response.json({ status: 'ok' }); } if (url.pathname === '/api/users' && req.method === 'POST') { const body = await req.json(); return Response.json({ id: 1, ...body }, { status: 201 }); } return new Response('Not Found', { status: 404 }); }, error(error) { return new Response(`Error: ${error.message}`, { status: 500 }); }, }); console.log('Server running on http://localhost:3000'); ``` ### With Hono (recommended for APIs) ```typescript import { Hono } from 'hono'; import { cors } from 'hono/cors'; import { logger } from 'hono/logger'; const app = new Hono(); app.use('*', logger()); app.use('/api/*', cors()); app.get('/api/users', (c) => { return c.json([{ id: 1, name: 'John' }]); }); app.post('/api/users', async (c) => { const body = await c.req.json(); return c.json({ id: 1, ...body }, 201); }); export default app; ``` ## File I/O ```typescript // Read file (returns string or ArrayBuffer) const text = await Bun.file('data.txt').text(); const json = await Bun.file('data.json').json(); const buffer = await Bun.file('image.png').arrayBuffer(); // Write file await Bun.write('output.txt', 'Hello World'); await Bun.write('data.json', JSON.stringify(data)); // Stream large files const file = Bun.file('large.csv'); const stream = file.stream(); for await (const chunk of stream) { process.stdout.write(chunk); } // File metadata const file = Bun.file('data.txt'); console.log(file.size); // bytes console.log(file.type); // MIME type ``` ## SQLite (Built-in) ```typescript import { Database } from 'bun:sqlite'; const db = new Database('app.db'); // Create table db.run(` CREATE TABLE IF NOT EXISTS users ( id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, email TEXT UNIQUE ) `); // Prepared statements (recommended) const insert = db.prepare('INSERT INTO users (name, email) VALUES (?, ?)'); insert.run('John', 'john@example.com'); const select = db.prepare('SELECT * FROM users WHERE id = ?'); const user = select.get(1); // Query all const all = db.prepare('SELECT * FROM users').all(); // Transaction db.transaction(() => { insert.run('Alice', 'alice@example.com'); insert.run('Bob', 'bob@example.com'); })(); ``` ## Environment Variables ```typescript // .env file loaded automatically const apiKey = Bun.env.API_KEY; const port = Bun.env.PORT ?? '3000'; // process.env also works const nodeEnv = process.env.NODE_ENV; ``` ## Shell Commands ```typescript import { $ } from 'bun'; // Simple command const result = await $`ls -la`; console.log(result.stdout.toString()); // With variables (auto-escaped) const filename = 'my file.txt'; await $`cat ${filename}`; // Piping const files = await $`ls`.text(); const count = await $`echo ${files} | wc -l`.text(); // Error handling try { await $`exit 1`; } catch (error) { console.error('Command failed:', error.exitCode); } ``` ## Configuration (bunfig.toml) ```toml # bunfig.toml [install] # Registry registry = "https://registry.npmjs.org" # Frozen lockfile in CI frozenLockfile = true [run] # Shell for scripts shell = "bash" [test] # Test configuration coverage = true coverageDir = "coverage" ``` ## Node.js Compatibility ```typescript // Most Node.js APIs work import { readFile } from 'fs/promises'; import { createServer } from 'http'; import path from 'path'; // Some differences import.meta.dir; // __dirname equivalent import.meta.file; // __filename equivalent // Check runtime const isBun = typeof Bun !== 'undefined'; ``` --- ## When NOT to Use This Skill | Scenario | Use Instead | |----------|-------------| | Node.js runtime specifics | `nodejs` skill | | Hono framework | Framework-specific skill | | Elysia framework | Framework-specific skill | | TypeScript syntax | `typescript` skill | | Testing strategies | `testing-vitest` skill | --- ## Anti-Patterns | Anti-Pattern | Why It's Bad | Correct Approach | |--------------|--------------|------------------| | Using node_modules/.bin | Not optimized for Bun | Use bunx instead | | Ignoring compatibility | Some npm packages fail | Test compatibility | | Complex routing in Bun.serve | Hard to maintain | Use Hono or Elysia | | Not pinning versions | Breaking changes | Use bun.lockb | | Mixing package managers | Inconsistent deps | Stick to bun | | Not using built-in SQLite | Extra dependency | Use bun:sqlite | | Blocking operations | Defeats performance | Use async APIs | | Not using watch mode | Slow dev loop | Use --watch flag | --- ## Quick Troubleshooting | Issue | Cause | Solution | |-------|-------|----------| | "Module not found" | npm compatibility issue | Check Bun compatibility list | | "bun: command not found" | Not installed | Install Bun or add to PATH | | Tests fail in Bun but not Jest | Different runtime | Check Bun-specific APIs | | Slow install | Network/cache issue | Clear cache with bun pm cache | | "Cannot find package" | Wrong specifier | Use npm: prefix for npm packages | | Type errors with .ts files | tsconfig mismatch | Check Bun's default config | | Build output incorrect | Wrong target | Set target in Bun.build | | SQLite errors | Database locked | Close connections properly | --- ## Performance Comparison | Task | Bun | Node.js | |------|-----|---------| | Install deps | ~2s | ~15s | | Run TS file | <100ms | ~500ms (tsx) | | HTTP requests/sec | ~100k | ~40k | | Test execution | ~200ms | ~2s | ## Production Readiness ```dockerfile # Dockerfile FROM oven/bun:1 AS base WORKDIR /app # Install deps FROM base AS deps COPY package.json bun.lockb ./ RUN bun install --frozen-lockfile # Build FROM base AS build COPY --from=deps /app/node_modules ./node_modules COPY . . RUN bun run build # Production FROM base AS production COPY --from=build /app/dist ./dist COPY --from=build /app/package.json ./ USER bun EXPOSE 3000 CMD ["bun", "run", "dist/index.js"] ``` ## Checklist - [ ] Bun installed (v1.0+) - [ ] bunfig.toml configured - [ ] Test suite with bun:test - [ ] Build script configured - [ ] Docker multi-stage for production - [ ] npm package compatibility verified --- ## Reference Documentation - [Bun Docs](https://bun.sh/docs) > **Deep Knowledge**: Use `mcp__documentation__fetch_docs` with technology: `bun` for comprehensive documentation. --- > Source: [claude-dev-suite/claude-dev-suite](https://github.com/claude-dev-suite/claude-dev-suite) — distributed by [TomeVault](https://tomevault.io).