[Webkit-unassigned] [Bug 227072] New: Service worker sometimes inactive after browser start up

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=227072

            Bug ID: 227072
           Summary: Service worker sometimes inactive after browser start
                    up
           Product: WebKit
           Version: Safari 14
          Hardware: Mac (Intel)
                OS: macOS 11
            Status: NEW
          Severity: Normal
          Priority: P2
         Component: Service Workers
          Assignee: webkit-unassigned at lists.webkit.org
          Reporter: marian.schaub at baqend.com

We are witnessing a strange behaviour in Safari Desktop regarding service workers when the browser is initially started.

Steps to reproduce:
1. Visit https://sw-lifecycle-test.app.baqend.com/swTest/test.html . The Page will display "No SW Response" and install a simple service worker.
2. Close Safari (command+Q).
3. Open Safari and visit https://sw-lifecycle-test.app.baqend.com/swTest/test.html again.

While repeating steps 2 + 3 we saw different outcomes. Our expectation would be to always see "SW Response" since the installed service worker simply intercepts the html request and delivers a page with that content.
What we found is sometimes the page displayed "SW Response", but often displayed "No SW Response". In these cases we did not see a service worker in Develop -> Service Workers context menu, but navigator.serviceWorker.controller
referenced the correct service worker. Reloading (both soft and hard reload) did not reliably lead to the service worker being activated again.

We were able to reproduce this on serveral Mac Book Pro machines running Safari 14.1.1 (16611.2.7.1.4).

After analyzing our tracking data we estimate about 4% of the Safari page impressions on our customers pages are affected by this.

-- 
You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.webkit.org/pipermail/webkit-unassigned/attachments/20210616/e9b5c49c/attachment.htm>