Adds tests/test_leaderboard.py — 30 cases against
diagnostics/leaderboard_routes.py. Two reasons:
(1) Zero coverage on an endpoint Argus + Oberon are about to consume
for the May 5 hackathon UI. Two bugs slipped through this morning
(404 wiring missing in app.py; AND-prefix SQL syntax error on
rolling-window). Tests prevent regression.
(2) Tests serve as living documentation for Oberon's frontend
integration — each test names a contract guarantee
(test_left_join_handles_missing_contributors_row,
test_composed_window_kind_domain, test_role_breakdown_present).
Coverage:
- _parse_window unit tests (10): all_time, Nd, Nh, caps, garbage,
case-normalization, and explicit no-AND-prefix assertion
- handle_leaderboard integration (18): every kind value, every
window family, domain filter, composed filters, limit + has_more,
invalid-input fallback, role breakdown shape, empty-window shape,
LEFT JOIN COALESCE for handles missing from contributors
- 2 contract assertions: LEADERBOARD_PUBLIC_PATHS membership +
KIND_VALUES set
Run: 30/30 pass on VPS hermes venv (aiohttp 3.13.5, pytest 9.0.2).
Skips clean locally without aiohttp via pytest.importorskip.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
