Packs ECMAScript/CommonJs/AMD modules for the browser. Allows you to split your codebase into multiple bundles, which can be loaded on demand. Supports loaders to preprocess files, i.e. json, jsx, es7, css, less, ... and your custom stuff.
The plugin's goal is to warn you when you import a css/scss module and then attempt to use a class which does not exist there. Pretty simple, it addition it will provide a list of all available classes from that module in hints, so that you can fix the problem.