This is the seventh video in the Understanding Service Workers course.
This video explains how you can use your Service Worker to handle an offline-first app as well has gracefully handling 404 errors. Also discussed are CORS errors with fetch calls from your Service Worker.
Code from Video: https://gist.github.com/prof3ssorSt3v3/7e5b8200dbe226049b49b6991396c7b3
MDN Request mode reference: https://developer.mozilla.org/en-US/docs/Web/API/Request/mode
MDN respondWith reference: https://developer.mozilla.org/en-US/docs/Web/API/FetchEvent/respondWith
Full Service Worker video playlist: https://www.youtube.com/watch?v=NJRu3pmmN-4&list=PLyuRouwmQCjl4iJgjH3i61tkqauM-NTGj