torqvoice/public/sw.js

const CACHE_NAME = 'torqvoice-offline-v1'
const OFFLINE_URL = '/offline.html'
const OFFLINE_ASSETS = [OFFLINE_URL, '/icons/icon-192.png']

self.addEventListener('install', (e) => {
  e.waitUntil(
    caches.open(CACHE_NAME).then((cache) => cache.addAll(OFFLINE_ASSETS))
  )
  self.skipWaiting()
})

self.addEventListener('activate', (e) => {
  e.waitUntil(
    caches.keys().then((keys) =>
      Promise.all(keys.filter((k) => k !== CACHE_NAME).map((k) => caches.delete(k)))
    )
  )
  self.clients.claim()
})

self.addEventListener('fetch', (e) => {
  if (e.request.mode === 'navigate') {
    e.respondWith(
      fetch(e.request).catch(() => caches.match(OFFLINE_URL))
    )
    return
  }

  if (OFFLINE_ASSETS.includes(new URL(e.request.url).pathname)) {
    e.respondWith(
      fetch(e.request).catch(() => caches.match(e.request))
    )
  }
})