1485842 - Support hidden prefs in metadata files

Status: RESOLVED FIXED

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

Description

[Karl Tomlinson (:karlt)]

Prefs that are already defined in all.js or elsewhere can be set in wpt
metadata files, but, when not already defined, the prefs items are silently
ignored, which can be hard to diagnose.

Workaround, once the problem is understood is to define the pref in
testing/profiles/unittest/user.js

(I don't actually know whether this is something to be fixed in the harness or the browser API that the harness uses to set the prefs.)

Comment 1

[Boris Zbarsky [:bzbarsky]]

Workaround, once the problem is understood is to define the pref in
testing/profiles/unittest/user.js

This doesn't actually work properly, because the harness will clearUserPref() between tests. So the result of the current setup is that when I run the webaudio/ wpts on a per-dir basis, I get a bunch of failures in webaudio/idlharness.https.window.html because that test runs second, and the prefs get cleared before it runs. Those failures are marked as expected, of course.

But if I run that test on its own, the prefs take effect and I get a bunch of unexpected passes. Also, if I add "dom.audioworklet.enabled" to StaticPrefList.h I get a bunch of unexpected passes....

Comment 2

[Boris Zbarsky [:bzbarsky]]

Attachment: Bug 1485842. Fix pref handling in the wpt harness to deal with prefs that aren't set already. r=jgraham,karlt

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/ce21500c025e
Fix pref handling in the wpt harness to deal with prefs that aren't set already. r=jgraham,karlt

Comment 4

[Web Platform Test Sync Bot (Matrix: #interop:mozilla.org)]

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/17103 for changes under testing/web-platform/tests

Comment 5

[Web Platform Test Sync Bot (Matrix: #interop:mozilla.org)]

Upstream web-platform-tests status checks passed, PR will merge once commit reaches central.

Comment 6

[Narcis Beleuzu [:NarcisB]]

https://hg.mozilla.org/mozilla-central/rev/ce21500c025e

Comment 7

[Web Platform Test Sync Bot (Matrix: #interop:mozilla.org)]

Upstream PR merged