Easily write your Jests in CoffeeScript.
Automatically handles transformation, including even tests written in literate CoffeeScript.
This will work on any .[lit]coffee[.md] file in your test[s] folder by default.
npm install jest-preset-coffeescript --save-dev, then add the following to your package.json:
"jest": {
"preset": "jest-preset-coffeescript"
},