Service Worker caching incorrectly

[BlueSlug]

Describe the bug

Content or design updates on the website are not always reflected after publishing which would prevent anyone with an older version of the site installed locally from seeing them. The solution is to deregister any active Service Workers in the client browser, at which point fresh copies of the site pages will be fetched and properly displayed.

This is a significant usability issue, for example when hundreds of resources which have been added are simply invisible to those experiencing the issue. Such affected users would have no indication that they are missing updated or additional site content and no way to know without following other channels of communication.

To Reproduce

Reproducing this bug requires making changes to the site which would require a page reload after publishing. This bug has not been observed outside of the production environment, however I suspect it is also a factor on the dev preview site and in the local development environment.

To reproduce the behavior, publish a change to the production site and observe whether the change is visible upon reloading the page.

Expected behavior

Site updates are correctly retrieved and displayed once published.

Screenshots

Desktop:

• OS: Multiple including Windows 10 Pro
• Browser: Multiple including Chrome 104

Additional context

#833 may benefit from solving this issue.

In my investigations into this issue, I noted that the service worker status, according to Chrome, was stuck at "trying to install". This was observed in production and in my local dev environment (see above).

I discovered an error in manifest.json relating to the purpose field of the 192px icon. It was set to any maskable rather than maskable (manifest.json:15), which could indeed be the source of the issue (I intend to test this with a PR deploy preview)

In addition to this, I also discovered errors with defining the scope of the Service Worker which I believe directly contributes to it being unable to install due to the service-worker.js file not being present.