NavigationPreloadManager: enable() method

The enable() method of the NavigationPreloadManager interface is used to enable preloading of resources managed by the service worker. It returns a promise that resolves with undefined.

The method should be called in the service worker's activate event handler, which ensures it is called before any fetch event handler can fire.

enable()

addEventListener("activate", (event) => {
  event.waitUntil(
    (async () => {
      if (self.registration.navigationPreload) {
        // Enable navigation preloads!
        await self.registration.navigationPreload.enable();
      }
    })()
  );
});