ServiceWorker's Fetch Handler Doesn't Return a Valid Response

[JammSpread]

Around mid-2021 Google seems to want to enforce PWAs have proper fetch handlers.
The consequence being no installability on at least Chrome.

I think it would be best to make sure that this is resolved prior to that "deadline".
(Although it's February so this may be too early.)

I'm thinking either #2007 (which may require that #1925 be reopened) could be reverted, or a page similar to the error page could be returned notifying the user that code-server cannot be used offline.

(You may be able to test this functionality by using the Chrome flag check-offline-capability.)

See more:

• https://web.dev/install-criteria/#criteria
• https://developer.chrome.com/blog/improved-pwa-offline-detection/

[JammSpread]

I'm thinking either #2007 (which may require that #1925 be reopened) could be reverted, or a page similar to the error page could be returned notifying the user that code-server cannot be used offline.

(Maybe the latter may look something like this):

[jsjoeio]

The consequence being no installability on at least Chrome.

We definitely don't want that to happen. Thanks for bringing this up sooner rather than later 🙌

I did see this as well in the link you provided:

TL;DR: Offline support has been part of the PWA installability criteria since the beginning. We are updating the offline detection logic to ensure a PWA actually provides an offline experience, closing the loophole used by some developers to meet the installability critiera. In the future, sites with empty fetch event handlers will no longer meet the criteria.

I'm actually in the middle of adding tests for our service worker code and thought it was strange we don't actually use the fetch handler in our service worker. It does nothing and I even have a test to make sure it does nothing 😂 (see here).

^I like the page you designed here above. Matches our other pages and communicates the issue clearly.

It sounds like we'll need to do two things:

• fix serviceWorker fetch handler (see example)
• add offline fallback page (see examples)

[jsjoeio]

Adding help-wanted in case anyone wants to grab this. Otherwise, I'll probably end up doing it

[greyscaled]

@jsjoeio Could be a great one for me to pick up

[jsjoeio]

Woo! All you! ♥️

[greyscaled]

@jsjoeio - I'm promising this by the first June milestone, with optimal hopes to get to it in the last week of May. Feel free to modify the milestones around this - and thanks for the patience!

[greyscaled]

Interesting updated - from one of the linked to articles Improving Progressive Web App offline support detection

An edit has been made:

Updated April 14th, 2021: We previously announced plans to update the installability criteria to ensure a PWA actually provides an offline experience. After listening to your feedback, and discovering a number of issues, we have decided to put those plans on hold. We strongly believe providing a valid page when the user is offline is critical to providing a good user experience.

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It seems we have more time to implement #2760 , though I don't think that means we should hold off. What it does mean, however, is we must continually monitor emerging PWA technologies.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no activity occurs in the next 5 days.

[jsjoeio]

Not stale

[douglasparker]

@code-asher can you please communicate why this is closed as not planned, so everyone following this issue isn’t left in the dark?

[code-asher]

It could be I misunderstood. From what I could tell, this is not going to change, so there is nothing we have to implement?

[douglasparker]

It could be I misunderstood. From what I could tell, this is not going to change, so there is nothing we have to implement?

Nothing that I have seen indicates that this is not going to change- Google has merely said that it is currently on hold.

[code-asher]

Definitely happy to reopen if that changes. PRs also welcome! Although, I think the long-term move might be to use VS Code's service worker rather than our own, but this will require some investigation.