Cache worker

cache_worker.js

// inside service worker eg. sw.ts

self.addEventListener('fetch', function (event) {
  if (event.request.url.endsWith('.mp4')) {
    event.respondWith(
      caches.match(event.request).then(function (response) {
        if (response) {
        
          return response
        } else {
          return fetch(event.request).then(function (response) {
            const responseToCache = response.clone()

            caches.open('cache_name').then(function (cache) {
              cache.put(event.request, responseToCache)
            })

            return response
          })
        }
      })
    )
  }
})