Think Greasemonkey for developers.
Witchcraft is a Google Chrome extension for loading custom Javascript and CSS directly from a folder in your file system, injecting them into pages that match their files names.
It works by matching every page domain against script file names available in the scripts folder. For instance, if one navigates to www.google.com, Witchcraft will try to load and run google.com.js and google.com.css.
For more information on how to install and use it, head to Witchcraft's home page.
Node.js is required, but just to run tests. I also use nvm to manage Node.js versions, but that's not required (just make sure your Node.js version is similar to the one .nvmrc currently points to). To install test dependencies:
cd <project-folder>
nvm install
npm install
Then you're ready to run tests:
npm test
Witchcraft is my rendition of defunkt's original extension, dotjs. Although I never got to actually use dotjs (it only worked for MacOS and the installation process was not easy), I really wanted something like that. Thanks, defunkt, for having such a cool idea.
Thanks arimus for the idea of using Web Server for Chrome.
The little witch and the witch hat icons were provided by Freepik.