cjyes #

🔍 see jay, yes! 🎉 / 👨🏻‍💻 see, JS! 👾 / ⚓️ sea JS ⛴

If you're publishing ES Modules, you need to also publish CommonJS versions of those modules.

This isn't to support old browsers or Node versions: even in Node 14, using require() to load a module won't work if it's only available as ESM.

cjyes is the bare minimum fix for this problem. You write ES Modules and fill out a valid package.json, and it'll generate the corresponding CommonJS files pretty much instantly. cjyes takes up 500kb of disk space including its two dependencies.

Usage#

The easiest way to use cjyes is to define package exports the way Node 13+ requires:

{
  "main": "index.mjs",
  "exports": {
    "import": "./index.mjs",
    "require": "./dist/index.cjs"
  },
  "scripts": {
    "prepare": "cjyes"
  },
  "devDependencies": {
    "cjyes": "^0.3.0"
  }
}

cjyes will create CommonJS versions of all modules listed in the "exports" field and place them at the specified locations.

You can also use .js file extensions and the {"type":"module"} field - cjyes will detect this and generate the required .cjs output files.

Multiple Entries#

Multiple entry points are supported automatically. Simply define them in your export map:

{
  "main": "index.mjs",
  "exports": {
    ".": {
      "import": "./index.mjs",
      "require": "./index.cjs"
    },
    "./jsx": {
      "import": "./jsx.mjs",
      "require": "./jsx.cjs"
    },
    "./hooks": {
      "import": "./hooks/index.mjs",
      "require": "./hooks/index.cjs"
    }
  },
  "scripts": { "prepare": "cjyes" },
  "devDependencies": { "cjyes": "^0.3.0" }
}

Custom Files#

It is also possible to pass a list of input modules to cjyes directly:

cjyes src/index.js src/other.mjs
# generates the following:
# dist/
#    index.cjs
#    other.cjs