[lawrencecchen]

Summary

Fixes the base red from #32127: WindowCleanupCoverageTests (Swift test shard 12) fails because #32127 added VerticalTabListViewTests, which makes an NSWindow in each test without the .closesItsWindows trait and only orders it out. Same pattern as #32217, #32086 and #29544.

Each test now closes its window in its teardown (closeAfterTest()), and the suite takes .closesItsWindows. No product code changes.

Testing

• Fleet package-test-lane.sh suite Packages/macOS/CmuxNext WindowCleanupCoverageTests,VerticalTabListViewTests at 679374d (job 3818290dadce0d134523e7fd): both suites passed (WindowCleanupCoverageTests 18 s, VerticalTabListViewTests 3 s).

Observed / Not run

Observed: the fleet run above. Not run: the full Swift shard 12.

Changelog

none

Proof

No capture: test-only change.

[github-actions]

cmux status _{(one comment, edited in place; each line is updated by the job that owns it)}

Review 679374d: HQ feed card · gallery before/after runs · checks

App of this head (app.zip, kept 1 day)

gh workflow run reload-build.yml -R manaflow-ai/cmux --ref feat-cmux-next -f tag=pr32439 -f ref=base-red-vtabs-windows -f platform=macos -f backend_mode=local

Shipped in:

• cmux NEXT nightly 1.0.0-nightly.4148415549501 (4729158bf9)
• cmux NEXT nightly 1.0.0-nightly.4148563744401 (dc06451eaf)
• cmux NEXT nightly 1.0.0-nightly.4148851513401 (736181335c)
• cmux NEXT nightly 1.0.0-nightly.4149093743601 (d6fe77646f)

[lawrencecchen]

Review (claude-review-subagent): SHIP at 679374d

• The top-level suite VerticalTabListViewTests has .closesItsWindows on its @Suite line, and the file imports CmuxNextTestSupport. This is the line that WindowCleanupCoverageTests.attributes(above:) reads.
• The suite makes one window, the borderless NSWindow in Harness. Each of the 5 tests makes one Harness, and the next line sets defer { harness.window.closeAfterTest() }. Harness.init does not throw, so the defer is set before any try. The old orderOut only hid the window, which the census counts as a leak.
• CmuxNextAppTests already depends on CmuxNextTestSupport in Package.swift. No Package.swift change is necessary, unlike cmux-next tests: DisplayBackdropBindingTests closes its windows (base red from #27092) #32217 (bba230b, where CmuxNextSettingsTests had to link it).
• VerticalTabListView opens no window of its own. The sibling suites that cmux NEXT: vertical tabs per workspace or for all workspaces #32127 added (VerticalTabListLayoutTests, VerticalTabsMenuTests, WorkspaceVerticalTabsTests, VerticalTabsSettingTests, TabStripMenuTests) do not open windows.
• origin/feat-cmux-next still has the old orderOut version, so this is not a duplicate fix.
• Not run: no local or fleet test run. This is a read-only review.