workout-tracker/views/serviceWorker.js

const CACHE_NAME = "Workout-Tracker";
const urlsToCache = ["/"];

self.addEventListener("install", (event)=>{
    event.waitUntil(
        caches
            .open(CACHE_NAME)
            .then(cache => cache.addAll(urlsToCache))
    );
});

self.addEventListener("fetch", (event)=>{
    event.respondWith(
        caches.match(event.request).then(response => {
            return response || fetch(event.request);
        })
    );
});