Step 2 of update() is: If registration's uninstalling flag is set, abort these steps. We don't currently do that. Its unclear, though, what the promise should be rejected with in this case. I'll open a spec issue.

Comment on attachment 8703736 [details] [diff] [review] Reject the promise returned from ServiceWorkerRegistration.update() if the registration is being uninstalled Review of attachment 8703736 [details] [diff] [review]: ----------------------------------------------------------------- Awesome, thanks! Do you think the current spec is consistent with this implementation?

No. I filed a spec issue: https://github.com/slightlyoff/ServiceWorker/issues/807