An extension of @author.io/karma-base, specifically for simplifying the scaffolding for web component tests.
Install as a development dependency.
npm install @author.io/karma-customelements -D
Make sure you've reviewed the @author.io/karma-base README, since it does the bulk of the work. This module makes it simpler to identify which files are tested in which environment (i.e. ES5 vs ES6).