Snippet to cache all angular.io content for offline access.

angular.io-offliner

/*
 * Run this snippet on https://angular.io or https://next.angular.io to let the ServiceWorker
 * cache all content (guides, API docs, etc.) and make it available for offline access.
 *
 * DISCLAIMER:
 * It's a hack. Not officially supported. Use at your own risk.
 * Works for me, but may not work for you (or it may stop working in the future). 
 */
(async () => {'use strict';

try {
  const manifest = await fetch('ngsw.json').then(res => res.json());
  const lazyUrls = manifest.assetGroups.find(g => g.name === 'docs-lazy').urls;
  const confirmed = confirm(`Download all ${lazyUrls.length} URLs?`);

  if (confirmed) {
    const start = performance.now();
    const responses = await Promise.all(lazyUrls.map(u => fetch(u)));
    const failedCount = responses.filter(r => !r.ok).length;
    const duration = Math.round((performance.now() - start) / 1000);

    alert(`Downloaded ${lazyUrls.length} URLs in ${duration}s. (${failedCount} failed.)`);
  }
} catch (err) {
  console.error(err);
  alert(`An error occurred:\n\n${err.stack}`);
}

})();