📦 obuild 😯

✅ Zero-config ESM/TS package builder.

Powered by oxc, rolldown and rolldown-plugin-dts.

The obuild project aims to be the next-generation successor to the current unbuild.

• 👌 Focus on ESM compatibility.
• 🌱 Fresh rewrite with cleanups and removal of legacy features.
• 🚀 Using oxc (for transform) and rolldown (for bundle) for much faster builds!

Some differences are not easy to adopt. Developing as a standalone project allows for faster progress and dogfooding in real projects.

Proof of concept

Important

This is a proof-of-concept project.

Features are incomplete, and API and output behavior may change between 0.x versions.

Feedback and contributions are very welcome! If you'd like to make changes with more than a few lines of code, please open an issue first to discuss.

Currently used by

• 📦 obuild
• 🌳 rou3
• 💥 srvx
• 🕊️ unenv
• 🕰️ omnichron
• [...add yours...]

Usage

CLI

# bundle
npx obuild ./src/index.ts

# transform
npx obuild ./src/runtime/:./dist/runtime

You can use --dir to set the working directory.

If paths end with /, obuild uses transpile mode using oxc-transform instead of bundle mode with rolldown.

Programmatic

import { build } from "obuild";

await build({
  cwd: ".",
  entries: ["./src/index.ts"],
});

Config

You can use build.config.mjs (or .ts) or pass config to build() function.

import { defineBuildConfig } from "obuild/config";

export default defineBuildConfig({
  entries: [
    {
      type: "bundle",
      input: ["./src/index.ts", "./src/cli.ts"],
      // outDir: "./dist",
      // minify: false,
      // stub: false,
      // rolldown: {}, // https://rolldown.rs/reference/config-options
      // dts: {}, // https://github.com/sxzz/rolldown-plugin-dts#options
    },
    {
      type: "transform",
      input: "./src/runtime",
      outDir: "./dist/runtime",
      // minify: false,
      // stub: false,
      // oxc: {},
      // resolve: {}
    },
  ],
  hooks: {
    // start: (ctx) => {},
    // end: (ctx) => {},
    // entries: (entries, ctx) => {},
    // rolldownConfig: (config, ctx) => {},
    // rolldownOutput: (output, res, ctx) => {},
  },
});

Stub Mode

When working on a package locally, it can be tedious to rebuild or run the watch command every time.

You can use stub: true (per entry config) or the --stub CLI flag. In this mode, obuild skips the actual build and instead links the expected dist paths to the source files.

• For bundle entries, .mjs and .d.mts files re-export the source file.
• For transpile entries, src dir is symlinked to dist.

Caveats:

• You need a runtime that natively supports TypeScript. Deno, Bun, Vite, and Node.js (1)
• For transpile mode, you need to configure your bundler to resolve either .ts or .mjs extensions.
• For bundle mode, if you add a new entry or add/remove a default export, you need to run the stub build again.

(1) For Node.js, you have several options:

• Using node --experimental-strip-types (Available in 22.6)
• Using jiti (node --import jiti/register)
• Using oxc-node (node --import @oxc-node/core/register)
• Using unloader (node --import unloader/register)

Prior Arts

• unbuild: Stable solution based on rollup and mkdist.
• tsdown: Alternative bundler based on rolldown.

License

💛 Released under the MIT license.