Bun is an all-in-one JavaScript runtime & toolkit designed for speed, complete with a bundler, test runner, and Node.js-compatible package manager
Intro#
Bun is an all-in-one toolkit for JavaScript and TypeScript apps. It ships as a single executable called bun.
At its core is the Bun runtime, a fast JavaScript runtime designed as a drop-in replacement for Node.js. It’s written in Zig and powered by JavaScriptCore under the hood, dramatically reducing startup times and memory usage
Install#
curl -fsSL https://bun.sh/install | bash
Using#
The bun command-line tool also implements a test runner, script runner, and Node.js-compatible package manager, all significantly faster than existing tools and usable in existing Node.js projects with little to no changes necessary.
bun run start # run the `start` script
bun install <pkg> # install a package
bun build ./index.tsx # bundle a project for browsers
bun test # run tests
bunx cowsay 'Hello, world!' # execute a package
bun CLI usage#
The bun CLI contains a Node.js-compatible package manager designed to be a dramatically faster replacement for npm, yarn, and pnpm. It’s a standalone tool that will work in pre-existing Node.js projects.
Run a JavaScript file or a package.json script:
bun run path/to/file|script_name
Run unit tests:
bun test
Download and install all the packages listed as dependencies in package.json:
bun install
Add a dependency to package.json:
bun add module_name
Remove a dependency from package.json:
bun remove module_name
Create a new Bun project in the current directory:
bun init
Start a REPL (interactive shell):
bun repl
Upgrade Bun to the latest version:
bun upgrade