Self-review on PR #2723 caught a coverage gap: the existing
"visibility gate" describe block actually tested cadence (10s/30s
timing), not the gate itself. If a refactor dropped the
`if (!visible) return` line, the cadence test would still pass
because the effect would still fire every 30s — the regression would
silently ship.
New test renders with comms-returning mock so the panel renders, clicks
the close button, advances 60s, asserts no further fetches occur.
Discipline-verified: removed `if (!visible) return` from the source,
test fails as expected. Restored, test passes.
Same failure mode as PR #434 (test asserted broken behavior) — pin
what you claim to fix, not the easy substring.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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