It's a headless testing tool. Description taken from: https://www.npmjs.com/package/casperjs CasperJS is a navigation scripting & testing utility for PhantomJS and SlimerJS (still experimental). It eases the process of defining a full navigation scenario and provides useful high-level functions, methods & syntactic sugar for doing common tasks such as:
- defining & ordering navigation steps
- filling forms
- clicking links
- capturing screenshots of a page (or an area)
- making assertions on remote DOM