2014443 - Using prefs entry in mochitest browser manifest only works in DEFAULT, not per-test (should either toml lint for this or fix)

Status: NEW

(Testing :: Mochitest, defect)

Description

[:Gijs (he/him)]

STR:

1. try to use a prefs annotation for an individual test (rather than in [DEFAULT] in the toml file)

ER:

either lint error or it works

AR:
neither, it is silently ignored

This works for xpcshell tests because the python harness manages individual test runs, but this isn't the case for mochitest browser. Might also not work for mochitest-plain/chrome, but I haven't checked.

Comment 1

[Andrew Halberstadt [:ahal]]

For mochitest it's only supported in the [DEFAULT] section by design as many prefs require a restart of the browser and we only restart between manifests.

I supposed we could implement it on a per-test basis for prefs that take effect immediately.. but I feel like that would be a source of confusion. I agree we should lint for this at the very least.