This package enables you to build a TypeScript package that's compatible with both CommonJS and ES Modules - without writing any duplicate code!

This is a heavy work in progress, use at your own risk!

yarn add --dev tsukuru
# or
npm install --save-dev tsukuru

Put this (or something similar) in your package.json:

{
    "main": "lib",
    "types": "lib",
    "exports": {
        ".": {
            "require": "./lib/index.js",
            "import": "./es/index.mjs"
        }
    },
    "scripts": {
        "build": "tsukuru",
        "rebuild": "tsukuru --clean"
    }
}

Assuming that your outDir is lib. The output directory of the ES Modules is currently hardcoded to be es.

Specifies the path to your TypeScript configuration file (tsconfig.json). If none is given, tsukuru will traverse your project directory and its ancestors until it finds a file named tsconfig.json.

Disables the use pf require('pkg') as a shortcut to the default export. Consumers must use require('pkg').default instead. This may considerably decrease your package's total size.

Removes the output directories before building.

This package runs the TypeScript compiler twice internally.

The first build will create a CommonJS version. It utilizes custom TypeScript transformers to augment and rearrange the module.exports statements so that you can use require('pkg') instead of require('pkg').default to access the default export of your package.

The second build will create an ES Module version. It will overwrite some of your tsconfig.json configuration to ensure compatibility with ESM modules. It also utilizes another custom transformer to resolve the import paths because node doesn't do that by default. Lastly, it renames the .js output files to .mjs in order to enable module importing without weird package.json hacks.

Sadly, the world of npm packages isn't quite ready yet for ESM. Please make sure that the package supports importing ESM before filing an issue here.

If it doesn't, maybe make a change by sending pull requests to your favorite libraries? ✨

It's Japanese for the verb "build" or "construct". It's usually written like this: 作る