[ServiceWorker Delete Caches which arent in list] src: https://developers.google.com/web/fundamentals/primers/service-workers/#update-a-service-worker #serviceworker

sw.js

self.addEventListener('activate', function(event) {

  var cacheAllowlist = ['pages-cache-v1', 'blog-posts-cache-v1'];

  event.waitUntil(
    caches.keys().then(function(cacheNames) {
      return Promise.all(
        cacheNames.map(function(cacheName) {
          if (cacheAllowlist.indexOf(cacheName) === -1) {
            return caches.delete(cacheName);
          }
        })
      );
    })
  );
});