Node.js & JS Toolchain¶

Package managers, runners, debugging, and TypeScript workflows.

Package Managers¶

Install dependencies:

npm install

Add a dev dependency:

npm install -D vitest

Run a script from package.json:

npm run build

Check for outdated packages:

npm outdated

Update interactively:

npx npm-check-updates -i

Drop-in npm replacement with faster installs and disk savings:

pnpm install
pnpm add -D typescript
pnpm run dev

Install: brew install pnpm · npm install -g pnpm

All-in-one runtime, bundler, and package manager:

bun install             # install deps (reads package.json)
bun run dev             # run scripts
bun add hono            # add a dependency

Run a file directly (no build step):

bun run server.ts

Install: brew install oven-sh/bun/bun · curl -fsSL https://bun.sh/install | bash

Run a package without installing globally:

npx create-next-app@latest my-app

Use a specific version:

npx -p typescript@5 tsc --init

Execute TypeScript without a build step (via Node.js):

tsx src/script.ts

Watch mode:

tsx watch src/server.ts

Install: npm install -g tsx

Start with the debugger:

node --inspect src/index.js

Break on first line:

node --inspect-brk src/index.js

Then open chrome://inspect in Chrome to connect.

Inline environment variables:

NODE_ENV=production node src/index.js

Load from .env file (Node.js 20.6+):

node --env-file=.env src/index.js

Run tests:

npx vitest run

Watch mode:

npx vitest

Run a specific test file:

npx vitest run src/auth.test.ts

Run tests matching a pattern:

npx jest --testPathPattern="auth"

Show coverage:

npx vitest run --coverage

Feature	npm	pnpm	Bun
Speed	Baseline	~2x faster	~5x faster
Disk usage	Duplicates deps	Hard links (saves space)	Compact
Lockfile	`package-lock.json`	`pnpm-lock.yaml`	`bun.lockb`
Built-in runner	No	No	Yes (TypeScript, JSX)
Compatibility	Universal	High	Growing