1803771 - Intermittent toolkit/components/extensions/test/browser/browser_ext_eventpage_disableResetIdleForTest.js | single tracking bug

Status: RESOLVED FIXED

(WebExtensions :: General, defect, P5)

Description

[Treeherder Bug Filer]

Filed by: ncsoregi [at] mozilla.com
Parsed log: https://treeherder.mozilla.org/logviewer?job_id=398454228&repo=autoland
Full log: https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/QxzEbJaDQxKjDDrCGs5jyA/runs/0/artifacts/public/logs/live_backing.log

---

[task 2022-12-02T12:54:43.874Z] 12:54:43     INFO - TEST-PASS | toolkit/components/extensions/test/browser/browser_ext_eventpage_disableResetIdleForTest.js | browserAction.onClicked listener expected to be primed - {"pendingEvents":[],"unregister":"() => {\n          this.off(\"click\", listener);\n        }","convert":"convert(newFire, extContext) {\n          fire = newFire;\n          context = extContext;\n        }"} == true - 
[task 2022-12-02T12:54:43.874Z] 12:54:43     INFO - Leaving test bound test_disableResetIdleForTest_true
[task 2022-12-02T12:54:43.875Z] 12:54:43     INFO - Buffered messages finished
[task 2022-12-02T12:54:43.876Z] 12:54:43     INFO - TEST-UNEXPECTED-FAIL | toolkit/components/extensions/test/browser/browser_ext_eventpage_disableResetIdleForTest.js | Unable to find a rejection expected by expectUncaughtRejection. - 1 == 0 - JS frame :: resource://testing-common/PromiseTestUtils.sys.mjs :: assertNoMoreExpectedRejections :: line 284
[task 2022-12-02T12:54:43.876Z] 12:54:43     INFO - Stack trace:
[task 2022-12-02T12:54:43.876Z] 12:54:43     INFO - resource://testing-common/PromiseTestUtils.sys.mjs:assertNoMoreExpectedRejections:284
[task 2022-12-02T12:54:43.877Z] 12:54:43     INFO - chrome://mochikit/content/browser-test.js:nextTest:676
[task 2022-12-02T12:54:43.878Z] 12:54:43     INFO - GECKO(4199) | JavaScript error: , line 0: AbortError: Actor 'Conduits' destroyed before query 'RunListener' was resolved
[task 2022-12-02T12:54:43.878Z] 12:54:43     INFO - Console message: [JavaScript Error: "AbortError: Actor 'Conduits' destroyed before query 'RunListener' was resolved"]
[task 2022-12-02T12:54:43.929Z] 12:54:43     INFO - GECKO(4199) | MEMORY STAT | vsize 11736MB | residentFast 498MB | heapAllocated 275MB
[task 2022-12-02T12:54:43.929Z] 12:54:43     INFO - TEST-OK | toolkit/components/extensions/test/browser/browser_ext_eventpage_disableResetIdleForTest.js | took 577ms

Comment 1

[Iulian Moraru]

Hi Luca! Can you please take a look at this? The backfill range and retriggers show that this is regressed by your recent changes in Bug 1745763.
Thank you!

Comment 2

[Intermittent Failures Robot]

3 failures in 3938 pushes (0.001 failures/push) were associated with this bug in the last 7 days.

Repository breakdown:

• autoland: 2
• mozilla-central: 1

Platform and build breakdown:

• linux1804-64-shippable-qr: 3
  • opt: 3

For more details, see:
https://treeherder.mozilla.org/intermittent-failures/bugdetails?bug=1803771&startday=2022-11-28&endday=2022-12-04&tree=all

Comment 3

[Luca Greco [:rpl] [:luca] [:lgreco]]

Attachment: Bug 1803771 - Prevent browser_ext_eventpage_disableResetIdleForTest.js intermittent failures. r?mixedpuppy!

This test was using PromiseTestUtils.expectUncaughtRejection to ignore the error "Actor 'Conduits' destroyed before ..."
triggered as a side-effect when the idle test page is being terminated while some API event listeners may have not
been removed and Gecko may still be in the process of trying to call the event listener in the child process, while the
listener was kept active by a setTimeout and a Promise tied to it.

I suspect that the intermittent failure may be due to the setTimeout which may be intermittently able to have freed the listener,
and in that case the error being asserted using expectUncaughtRejection may not be actually be rejected.

To make sure this test behavior isn't going to be too tied to the race between setTimeout and the test being able to call
extension.terminateBackground, this patch is:

• replacing the the Promise + setTimeout used to keep the listener with a "never resolved" Promise, which would never be resolved
  and so it should not be subjected to a race.

• replacing the PromiseTestUtils.expectUncaughtRejection call inside the single test with a
  PromiseTestUtils.allowMatchingRejectionsGlobally called for the entire test file, because
  in the end the Conduits JS Actors rejection are more of a side-effect and the test is explicitly asserting
  the behaviors directly expected (in particular the listeners being primed or not as expected), and it is also
  how to properly ignore errors that are too tight to potential races (e.g. between when we are triggering the
  browserAction onClicked and when the call to the listeners is about to be send across ipc to the extensions
  child process).

Comment 4

[Luca Greco [:rpl] [:luca] [:lgreco]]

I'm not 100% convinced that Bug 1745763 is actually what have introduced intermittency in this particular test, in particular it seems that the new test file landed only a couple of days before Bug 1745763 and in the retriggers it seems that with the changes from Bug 1745763 included it did only fail once over 15 job runs.

And so there is actually a chance that the failure would have had a low enough intermittency rate even without Bug 1745763 changes (or that Bug 1745763 may have chanced slightly some timing enough for the test to be more likely to trigger a pre-existing intermittency issue).

Anyway, I looked to the test case and even if I was not able to trigger the same intermittent failure locally, there are a couple of details in the test that looked a possible source of intermittent failures and so in comment 3 I'm attached a patch with some proposed tweaks meant to take care of that.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/mozilla-central/rev/cd04453b7a9c
Prevent browser_ext_eventpage_disableResetIdleForTest.js intermittent failures. r=mixedpuppy

Comment 6

[Marian-Vasile Laza]

https://hg.mozilla.org/mozilla-central/rev/cd04453b7a9c