The following is a mix of spec and implementation issues that I encountered in my as-of-yet unsuccessful attempt to make use of service workers in the ASF Board Agenda tool.

1) the "offline fallback" use case for Service Workers involves intercepting fetch requests, issuing the request, and then recovering from any errors that may occur. Unfortunately, issuing the event.request will not faithfully reproduce the original navigate request, in particular, credentials are not included.

2) passing credentials: 'include' on fetch requests within a service worker will succeed if the browser has access to the credentials (e.g. due to prompting the user earlier in the browser session). If the credentials are not present, Firefox will prompt for this information. Chrome will not. This is a showstopper for offline access to an authenticated web page with Chrome.

3) event.request.headers.get("Authorization") is available on Firefox but not on Chrome.

4) cache.keys() is supposed to return a promise. On both Firefox and Chrome, cache.keys() returns an empty array instead. cache.matchAll() can be used to get all of the responses, but not the keys.

5) calling registration.unregister() followed by navigator.serviceWorker.getRegistrations() will still return a list containing the now unregistered service worker in both Firefox and Chrome.

6) EventSource is available to service workers in Chrome but not in Firefox. Using importScripts in an attempt to load the Yaffle polyfill doesn't work.

Advice on how to proceed with these issues (filing bugs on the spec and/or one or more implementations, perhaps?) would be greatly appreciated.


- Sam Ruby

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