[BUG] PWABuilder Report Card is not recognizing the service worker running (site: https://pwhl-remix.vercel.app/)

[smoak]

[BUG] PWABuilder Report Card is not recognizing the service worker running (site: https://pwhl-remix.vercel.app/)

[Jaylyn-Barbee]

On first load of your site, I don't see a service worker registered. It isn't until I refresh that your service worker loads and is activated. Since it is a bot looking for your SW and it's not loading on the first pass, this could be why your SW isn't being detected.

Update: I have been playing with this for a few more minutes and the behavior is a bit different across browsers and even in incognito. Going to get some more people on the team to mess around with this to double check.

[khmyznikov]

@smoak @Jaylyn-Barbee getting same behaviour in Edge and Kiwi Mobile. After 5-6 refreshes I have finally got the SW in Edge. Clean website data and check your app logic. In Chrome I can't reproduce this... Try to not use windows load event at all in sw registration.

Update: yeah, it's definitely a problem in this event. It's triggers before this code and never executes.

[jgw96]

As this is an issue in yalls service worker, I am going to close this issue for now, but please feel free to open a new issue if you make our suggested changes and still hit issues. Thanks for using PWABuilder!

[smoak]

Try to not use windows load event at all in sw registration.

@khmyznikov Can you help me understand why I shouldn't use this? The workbox docs suggests waiting until the page is fully loaded before registering the service worker

Further documentation suggests this as well:

If a service worker precaches anything, then the time at which it's registered matters. Service workers are often registered using inline <script> elements. This means HTML parsers may discover service worker registration code before the page's critical assets have loaded.

This is a problem. A service worker should ideally be performance-neutral in the worst of cases, not make performance worse. Do users a favor and register a service worker when the page's load event fires. This reduces the chance that precaching will interfere with loading a page's critical assets, which in turn means the page can get interactive faster without having to contend with network requests for assets that may not be needed until later anyway.