1936688 - Tag some Customizable UI tests to run under the vertical-tabs variant

Status: NEW

(Firefox :: Sidebar, task, P3)

Description

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

Bug 1902032 creates a new browser-mochitest-chrome test variant which flips sidebar.verticalTabs=true when running tests tagged with vertical-tabs. Running with the pref already set on Customizable UI tests not explicitly written to cover vertical tabs could catch regressions and unexpected fallout.

For the most part this involves adding the tag = "vertical-tabs" line under each test we want to opt-in to the new variant. But it might also make sense to refactor some tests to take advantage of the variant and remove redundant code which accomplishes the same thing. If there's a test which should run and pass in this configuration but fails, we can either fix it, or skip for now with skip-if = ["vertical_tab"] and file a bug.

We don't currently have support from testing locally with the variant, you'll just need to mach test --setpref="sidebar.verticalTabs=true" browser/components/customizableui, but when you push to try you should make sure the -vt suffixed browser-mochitest-chrome tasks are selected.