The custom service worker logic or workflow utilizes different libraries to render content on the client. The two third-party libraries are localForage for IndexedDB interactions and Mustache to render markup.
localForage (https://localforage.github.io/localForage/) is another IndexedDB wrapper. It provides a simple interface that mimics localStorage. The main difference is that localForage supports promises, making it asynchronous.
There are three polyfils, and these are Object.assign, Promise, and Fetch.
Each page uses a few application-specific libraries: api and push-mgr, and common application modules. Each...