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fix: let two tests render under t.Parallel without racing - #671
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Model.View() sets the package-level Active* and Nyan* variables that the renderers read a moment later, so two renders on different goroutines race them. Bubble Tea renders on one goroutine, so this is latent in production, but any second test that renders under t.Parallel() trips -race. Two tests carried a comment saying they could not be parallel because of it. Guarding each variable would not fix it: a frame needs all of them to come from the same Model, so a per-variable lock would still let one render read another Model's values. ui.RenderMu takes the whole pass instead, which is what the assignments and the renderers actually share. An uncontended mutex costs nothing against a multi-millisecond render.
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WalkthroughThe change adds Merge Risk: ⚪ Minimal · up to This change serializes shared render state and enables the affected tests to run in parallel; no actionable merge-blocking risk remains after normal checks and review. 🚥 Pre-merge checks | ✅ 5✅ Passed checks (5 passed)
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Model.View()sets the package-levelui.Active*andui.Nyan*variables that the renderers read a moment later. Two renders on different goroutines therefore race them, and worse than racing, one can read another Model's values.Bubble Tea renders on a single goroutine, so this is latent in production. It shows up in tests: any second test that renders under
t.Parallel()trips-race. Two tests indiscovery_failure_level_test.gocarried a comment saying they could not be parallel because of it.Why a lock rather than parameters
The original plan was to turn
ActiveCollapsedCategoriesandActiveCategoryCountsinto parameters. The race detector showed the problem is wider than those two: the first report lands onview.go:87, which isui.NyanMode, and the same block sets the security-badge state right after.RenderColumnalready takes nine parameters, and threading a dozen values through it would be a large change to a hot path for a latent bug.Guarding each variable individually would not fix the real defect either. A frame needs all of them to come from the same Model, so a per-variable lock would still let one render read another Model's values and paint a wrong frame.
ui.RenderMutakes the whole pass, which is the unit the assignments and the renderers actually share. An uncontended mutex costs about 20ns against a multi-millisecond render.Test plan
TestDiscoveryFailureAt*tests now callt.Parallel()and pass under-racet.Parallel()added and no lock, all three parallel tests reportrace detectedgo test -race ./internal/app/...(3 consecutive runs)golangci-lint run ./internal/...reports 0 issuesTestWatchTickAgeAdvancesOnMemoizedItemsalready hadt.Parallel()and was racing silently until another parallel test joined it.