On the next merge to mozilla-central, the `mach test --headless` command will no longer give an error on directories containing xpcshell tests <https://bugzilla.mozilla.org/show_bug.cgi?id=1550518> (along with other suites already supporting --headless). Prior to this enhancement the command would fail as soon as an xpcshell test was encountered since that harness didn't support the argument. This required running mach multiple times in order to execute all tests for a component. Now you no longer have to worry about whether the tests you execute have a mix of xpcshell and mochitest flavors when deciding whether to use --headless.
This also means that `mach xpcshell-test --headless` doesn't error, but that's probably not too interesting for most developers on its own as the xpcshell test harness already supported running specific tests in headless mode with the `headless = true` xpcshell.ini annotation <https://searchfox.org/mozilla-central/search?q=headless+%3D&case=false®exp=false&path=xpcshell.ini>. The --headless command line argument has the same behavior as that annotation <https://searchfox.org/mozilla-central/rev/4e228dc5f594340d35da7453829ad9f3c3cb8b58/testing/xpcshell/runxpcshelltests.py#686-687>, it's not a no-op, so it may change some behaviour in tests involving rendering though those are likely very rare in this suite. Also note that this configuration isn't run in automation so it's possible some tests will fail under it but don't without --headless so you may want to run a test without the argument if you're seeing an unusual failure that doesn't appear in automation. In that case you could opt the test out of headless mode with `headless = false` in the manifest. Thanks to Geoff Brown for the quick review. Matthew N. (:MattN) _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
