1181036 - "Harness status: OK" + failing test when running "registration-service-worker-attributes.https.html" test

Status: RESOLVED FIXED

(Testing :: web-platform-tests, defect)

Description

[Noemí Freire (:noemi)]

Checked with 7/6 master build

Test run such as |./mach web-platform-tests _mozilla/service-workers/service-worker/registration-service-worker-attributes.https.html|

Result:
* Harness status: OK
* Found 1 tests
* 1 Fail:
** installing/waiting/active after registration
*** assert_unreached: unexpected rejection: registration.waiting is null Reached unreachable code
unreached_rejection/<@https://web-platform.test:8443/_mozilla/service-workers/service-worker/resources/test-helpers.sub.js:42:7 Test.prototype.step@https://web-platform.test:8443/resources/testharness.js:1363:20 Test.prototype.step_func/<@https://web-platform.test:8443/resources/testharness.js:1387:1 Promise*@https://web-platform.test:8443/_mozilla/service-workers/service-worker/registration-service-worker-attributes.https.html:11:5 Test.prototype.step@https://web-platform.test:8443/resources/testharness.js:1363:20 async_test@https://web-platform.test:8443/resources/testharness.js:513:13 @https://web-platform.test:8443/_mozilla/service-workers/service-worker/registration-service-worker-attributes.https.html:6:1 
* Traces: https://pastebin.mozilla.org/8838627

Comment 1

[Nikhil Marathe [:nsm] (No longer reading bugmail, please needinfo?)]

I think the test implements some Blink specific behaviour here but alternative interpretations are possible.

The [[Install]] algorithm states towards the end (after it has set waiting's state to INSTALLED), something along the lines of "wait until there are no controlling documents, then activate this worker", which means [[Activate]] can run immediately after [[Install]]. Since this happens in the same thread as the ServiceWorkerRegistration in firefox, this means that a worker can go from installing -> activating with the page unable to observe the intermediate waiting state. In Blink, due to the multiprocess model, the event loop in the content process spins between the waiting -> active transition, i.e.:
1) Parent process finishes [[Install]] leading to a message being sent to child processes to update there 'registration.waiting'. Child then sends event 'statechange', the wpt test runner wait_for_state()'s Promise is resolve()d.
2) Child event loop spins, Promise resolution is noted, test passes.
3) Parent continues with [[Activate]].

and the page can reliably observe that. I don't know who is correct in this case, nor do I know how bug 1182117 will change this for firefox.

Comment 2

[Nikhil Marathe [:nsm] (No longer reading bugmail, please needinfo?)]

Attachment: MozReview Request: Bug 1181036 - Fix waiting/active expectations. r=bkelly

Bug 1181036 - Fix waiting/active expectations. r?bkelly

Update web-platform-tests expected data

Comment 3

[Noemí Freire (:noemi)]

Hi, 

Patch provided by Nikhil so assigning this to him. Please, feel free to change it as needed. Thanks!

Comment 4

[Ben Kelly [:bkelly, not reviewing]]

Comment on attachment 8655148 [details]
MozReview Request: Bug 1181036 - Fix waiting/active expectations. r=bkelly

https://reviewboard.mozilla.org/r/17841/#review16009

::: testing/web-platform/mozilla/tests/service-workers/service-worker/registration-service-worker-attributes.https.html:60
(Diff revision 1)
> -          assert_equals(registration.active.scriptURL, expected_url,
> +          // According to spec, the Update State step is immediately followed

nit: I found this comment a little confusing.  Maybe clarify that the Clear Registration algorithm sets the active worker to null immedately after the Update State step.

Comment 5

[Nikhil Marathe [:nsm] (No longer reading bugmail, please needinfo?)]

Comment on attachment 8655148 [details]
MozReview Request: Bug 1181036 - Fix waiting/active expectations. r=bkelly

Bug 1181036 - Fix waiting/active expectations. r=bkelly

Update web-platform-tests expected data

Comment 6

[Nikhil Marathe [:nsm] (No longer reading bugmail, please needinfo?)]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=b77e44be85ca

Comment 7

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/4374022a52d9

Comment 8

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/4374022a52d9

Comment 9

[Noemí Freire (:noemi)]

Hi,

just checked on m-c (139446daedab revision) and the tes successfully runs. Thanks for fixing it!.

Summary

Harness status: OK

Found 1 tests
1 Pass
Details
Result	Test Name
Pass	installing/waiting/active after registration