1994508 - Investigate test failures for browser_tab_splitview_contextmenu.js on mac 10.15 builds

Status: ASSIGNED

(Firefox :: Tabbed Browser: Split View, task, P3)

Description

[Kelly Cochrane [:kcochrane]]

In bug 1986946, we added a new test for the tab context menu to create and unsplit split views. For some reason, the test is timing out only on mac 10.15 builds as the context menu never opens in some instances. We should investigate why that is so we can unskip the test on that platform.

Comment 1

[Sam Foster [:sfoster] (he/him)]

Its possible the changes in bug 1994212 might help here, or would at least be a base to start from.

Comment 2

[Stephen Thompson [:sthompson]]

Attachment: Bug 1994508 - fix intermittent browser_tab_splitview_contextmenu.js r=kcochrane

Updates MutationObserver arguments to ensure that the observers get called when the mutation condition holds.

This test was failing intermittently and caused an unrelated patch of mine (bug 2015874) to be backed out. I couldn't figure out why or whether my patch might be causing problems to this test. However, I was able to consistently reproduce this test's timeouts on Windows on firefox-main without any of my patches.

1. MutationObserver monitors child elements using childList, not children
2. The "remove split view from group" menu item is tricky because the l10n engine changes the label attribute from "Remove from Groups" to "Remove from Group" but there are two mutation observers: this test, and the menuitem itself. The menuitem has a mutation observer that reflects label attribute changes to its .menu-text child's text content, but there is a risk that this test's mutation observer runs before the menuitem. In order to ensure that the test can always see changes to the textContent, it was not enough to just use characterData because the text is updated on a child element. Both characterData and subtree seemed to consistently pick up changes to the menuitem text.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/32b1e1a2c6fa
https://hg.mozilla.org/integration/autoland/rev/df0a078d74ee
fix intermittent browser_tab_splitview_contextmenu.js r=kcochrane,tabbrowser-reviewers

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/acf5d703fe96
https://hg.mozilla.org/integration/autoland/rev/c9dc71e9fc09
Revert "Bug 1994508 - fix intermittent browser_tab_splitview_contextmenu.js r=kcochrane,tabbrowser-reviewers" for causing failures @browser_tab_splitview_contextmenu.js.

Comment 5

[Goloman Adrian[:agoloman]]

Backed out for causing failures @browser_tab_splitview_contextmenu.js.

• Backout link
• Push with failures
• Failure Log

Comment 6

[Phabricator Automation]

Comment on attachment 9547667 [details]
Bug 1994508 - fix intermittent browser_tab_splitview_contextmenu.js r=kcochrane

Revision D284736 was moved to bug 1996471. Setting attachment 9547667 [details] to obsolete.