1.What is Bun?
Before we get to 1.3, let us quickly see what Bun is.
Imagine you have a toolbox for building web applications and running JavaScript outside of a web browser. In that toolbox, you usually have things like Node.js (to run your code), npm or Yarn (to manage your project's packages/dependencies), and maybe a bundler like Webpack or Vite (to optimize your code for the browser).
Bun's big idea is to be one super-fast tool that does all of that, and more. It's like having a Swiss Army knife that replaces your whole toolbox, and it's built from the ground up to be incredibly speedy. It's written in a low-level language called Zig, which helps it achieve that performance.
2.Key Features of Bun
Runtime: It can run your JavaScript and TypeScript code, just like Node.js.
Package Manager: It can install, update, and manage your project's dependencies, similar to npm or Yarn. But it's way faster.
Bundler: It can package your code for the browser, like Webpack or Vite, but again, super fast and built-in.
Test Runner: It has its own built-in test runner.
Transpiler: It understands TypeScript and JSX (React's syntax) out of the box, so no extra setup is needed.
3.What's New and Exciting in Bun 1.3?
Bun 1.3 brings a bunch of improvements
Faster bun install: This is a big one! If you've ever waited for npm install to finish, you know the pain. Bun's package manager (bun install) was already fast, but 1.3 makes it even faster, especially for projects with lots of dependencies. They've optimized how it fetches and installs packages. This means less waiting and more coding for you!
Windows Compatibility: (More Stable!) While Bun has been available on Windows for a bit, 1.3 significantly improves its stability and performance on the platform. They've fixed a lot of bugs and made it feel much more native and reliable for Windows users.
New Bun.Glob API: This is a developer-centric feature that's pretty handy. "Globbing" is a fancy way of describing pattern matching for file paths. For example, if you want to find all .js files in a src folder, you might use a glob pattern like src/**/*.js. Bun.Glob provides a super-fast, built-in way to do this. Before, developers often had to install separate packages to handle globbing. Now it's part of Bun, and it's optimized for speed.
fetch API Improvements: The fetch API is a standard way to make network requests (like getting data from a server). Bun 1.3 brings significant performance boosts and better compatibility for its fetch implementation. This means your applications that make a lot of network requests will run even quicker and more reliably.
More Node.js Compatibility: Bun aims to be a drop-in replacement for Node.js. With each release, it gets closer to 100% compatibility. Bun 1.3 continues this trend by improving support for more Node.js APIs and modules. This means fewer headaches when migrating existing Node.js projects to Bun.
4.Why Should Developers Care About Bun 1.3?
Speed: It's the recurring theme. Faster development, faster execution, faster installations.
Simplicity: One tool to rule them all. Less configuration, less context switching between different tools.
Modernity: Built for the modern JavaScript ecosystem, with native TypeScript and JSX support.
Growing Ecosystem: With improved Windows support and Node.js compatibility, Bun's community and adoption are likely to grow even faster.
5.Getting Started
You can install Bun in your machine using the below command
curl -fsSL https://bun.sh/install | bash
or if you have installed bun already you can simply upgrade it
bun upgrade
6.Bun for MonoRepos
While Bun 1.3 itself didn't introduce new, dedicated features specifically for monorepos in the way that tools like Lerna, Turborepo, or Nx do, it significantly improves the experience of working with monorepos due to its core enhancements.
a. Faster bun install is a Game Changer for Monorepos
The Problem in Monorepos: Monorepos often have many package.json files (one per package/workspace) and a large, shared node_modules directory. Running npm install or yarn install in a monorepo can be notoriously slow, especially for clean installs or when adding new dependencies.
Bun 1.3's Solution: The even faster bun install directly addresses this pain point. When you run bun install at the root of your monorepo, it's designed to be incredibly efficient at resolving and linking all those dependencies across multiple workspaces.
This means Quicker Setup New developers joining the project or CI/CD pipelines will get up and running much faster. Faster Dependency Changes: Adding or updating a dependency in one package won't bring your entire monorepo workflow to a crawl.
b.Improved Node.js Compatibility
Monorepo Tools often Rely on Node.js: Many existing monorepo management tools (like Lerna, Turborepo, Nx, or even simple custom scripts) are built on Node.js.
Bun's Benefit: As Bun's Node.js compatibility improves with 1.3, it means that these tools (or your own Node.js-based scripts within the monorepo) are more likely to run seamlessly with Bun as the underlying runtime. You can leverage Bun's speed for script execution across your workspaces without hitting compatibility walls.
c. Built-in TypeScript and JSX Support
Common in Monorepos: It's very common for different packages within a monorepo to use TypeScript, React (JSX), or both.
Bun's Advantage: Bun's native support means you don't need complex tsconfig.json setups or extra transpilers (like Babel or ts-node) for each package just to get things running or test them. Bun can execute your TypeScript and JSX files directly, simplifying the development experience across your monorepo's packages.
7.Package Management
Bun's package manager gets more powerful with isolated installs, interactive updates, dependency catalogs.
a. Catalogs Synchronization
Bun 1.3 makes it easier to work with monorepos.
Bun centralizes version management across monorepo packages with dependency catalogs. Define versions once in your root package.json and reference them in workspace packages.
{
"name": "monorepo",
"workspaces": ["packages/*"],
"catalog": {
"react": "^18.0.0",
"typescript": "^5.0.0"
}
}
Reference catalog versions in workspace packages:
{
"name": "@company/ui",
"dependencies": {
"react": "catalog:"
}
}
b. Isolated installs are now default for workspaces
Bun 1.3 introduces isolated installs. This prevents packages from accessing dependencies they don't declare in their package.json. Unlike hoisted installs (npm/Yarn's flat structure where all dependencies live in a single node_modules), isolated installs ensure each package only has access to its own declared dependencies.
And if you use "workspaces" in your package.json, it is made as default.
To opt-out you can do either one of the thing
bun install --linker=hoisted
or just update it in bunfig.toml
[install]
linker = "hoisted"
c. New Commands
Bun 1.3 adds several commands that make package management easier
bun why - explains why a package is installed
bun update --interactive - lets you choose which dependencies to update
bun info - lets you view package metadata
bun install --analyze - lets you scans your code for imports that aren't in package.json and installs them
bun audit scans dependencies for known vulnerabilities using the same database as npm audit
8.Explore more about Bun
