Service worker checker

What is checked

The page's static HTML is scanned for a navigator.serviceWorker.register(...) call; if one is found, the registered script itself is fetched and checked for HTTPS delivery, reachability, MIME type, and a text-level scan for install, activate and fetch event listeners and Cache API usage.

Static inspection, not execution

This never runs the service worker - it reads the registered file as text. A registration added dynamically by a separately-loaded script bundle, or lifecycle listeners attached through a helper function rather than a literal addEventListener call, will not be visible to this check.