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Service Worker (sw.js)

A sample cache-first service worker handling install, activate, and fetch events with an offline fallback, for testing service-worker registration, JS parsers, and PWA tooling.

Web assets Syntax highlighting Editor testing

Preview, first 29 linesjs

// sw.js - a sample service worker (cache-first for static assets, network
// fallback, and offline page). Illustrative fixture, not wired to a real app.
const CACHE = "novus-static-v1";
const ASSETS = ["/", "/index.html", "/styles.css", "/app.js", "/offline.html"];

self.addEventListener("install", (event) => {
  event.waitUntil(caches.open(CACHE).then((cache) => cache.addAll(ASSETS)));
  self.skipWaiting();
});

self.addEventListener("activate", (event) => {
  event.waitUntil(
    caches.keys().then((keys) =>
      Promise.all(keys.filter((key) => key !== CACHE).map((key) => caches.delete(key))),
    ),
  );
  self.clients.claim();
});

self.addEventListener("fetch", (event) => {
  const { request } = event;
  if (request.method !== "GET") return;
  event.respondWith(
    caches.match(request).then(
      (cached) => cached || fetch(request).catch(() => caches.match("/offline.html")),
    ),
  );
});

Specifications

Language: JavaScript
Strategy: cache-first + offline fallback
Events: install, activate, fetch

Testing contract

Expected to pass

Scenario: Exercise Service Worker (sw.js) in its pwa workflow. A sample cache-first service worker handling install, activate, and fetch events with an offline fallback, for testing service-worker registration, JS parsers, and PWA tooling.
Expected result: 28 text lines, decoded as UTF-8; first nonempty line is `// sw.js - a sample service worker (cache-first for static assets, network`. Declared feature checks: language=JavaScript; strategy=cache-first + offline fallback; events=install, activate, fetch.

What is a .js file?

JavaScript (.js) is a plain-text source file for the JavaScript language: the scripting language of the web, also used server-side via Node.js. It is dynamically typed and event-driven, with first-class functions, prototypes, and (in modern syntax) modules, classes, and async/await.

How to use this file

Use an example .js file to test syntax highlighters, linters (ESLint), formatters (Prettier), bundlers, and JavaScript parsers, or as editor and diff-viewer fixtures.

How to use this file for testing

“Service Worker (sw.js)” is a deterministic Testaroo fixture for Web assets, Syntax highlighting, Editor testing. Favicons, web app manifests, service workers, robots and sitemap files, Open Graph images, and .well-known resources, for testing web tooling, crawlers, PWA installers, and asset pipelines.

Documented properties for this file: JavaScript. Compare results against paired or grouped companions on this page when present (clean↔damaged, searchable↔scanned, or format twins) so scores stay reproducible across runs.

Download the file once, keep the path stable in CI or local scripts, and treat the spec table as the contract: dimensions, seeds, field lists, and roles are intentional. Corrupt or invalid samples are labelled as such, expect parsers to fail loudly rather than silently accept them.

Web-platform fixtures are standards-compliant samples against fictional example.com data. Test crawlers, PWA installers and manifest validators, favicon/icon pipelines, service-worker registration, or .well-known parsers against the documented structure.