docs/ui-information-architecture-review.md claimed Priority 0 was guarded by
analytics-sql.test.ts. That file only ever covered the three SQL *fragments*
(EXCLUDE_RECONCILED_SOURCE, NATIVE_CURRENCY, INVESTMENT_SIGNED). Items 2, 3 and
6 of the Priority 0 list had nothing, and all three fail silently — no error,
no empty screen, just a number that quietly disagrees with the one beside it.
New: src/__tests__/integration/analytics-priority0.test.ts, 18 tests.
- **Item 2, pace/headline parity.** /api/analytics/daily summed over a month
must equal /api/analytics/monthly's headline to the cent, per category, and
across every month in the window. Cents rather than exact equality is the
assertion because the two routes group at different grains (month+category
vs month+day+category) and both carry 4dp — the displayed grain is what has
to agree, which is precisely the bug (the chart ending the month a few cents
off the headline above it). Fixtures are only shapes where a naive gross
debit sum disagrees: a 50% split, a refund, fee and interest rows, an
itemised loan repayment, a reconciled source row, family-tagged spend,
transfers/investment/income, and a row someone else paid that I hold a split
on. A fourth test asserts the naive sum does NOT match — without it, parity
between two queries identical by construction would pass on fixtures too
plain to discriminate.
- **Item 3, fees date range.** Default 12 months with the window reported
(from=2025-09-01, not 08-31 — toDateStr, not toISOString); the older tail
excluded; months=0 all-time with a null range rather than a period claim the
number does not make; a narrower months=3; the transaction-level fee lines
bounded by the same window as the statement totals, since a bounded total
beside an unbounded list is the same defect wearing the fix; and a nonsense
months param clamped rather than producing an Invalid Date window.
- **Item 6, partial-month comparisons.** The in-progress month never enters a
baseline; a partial month is compared through the same day of each prior
month; a complete month keeps full totals; top movers truncate both sides;
year boundary and leap February.
Item 6 was untestable by construction, which is why it had no test: the rules
were closures in budget/page.tsx reading `new Date()` inline. Extracted to
src/lib/partial-month.ts with an injectable clock, and budget/page.tsx now
imports them. The extraction also de-duplicates the baseline filter, which was
written out identically in two places.
The file freezes the clock (vi.useFakeTimers, toFake: ["Date"] only — pg needs
real timers for connection handling). Without it the fixtures drift out of the
routes' rolling windows over time and the assertions go vacuous, which is the
same class of silent failure the file exists to catch.
Mutation-checked, all three: breaking daily's spend semantics fails 3 of the
item-2 tests (the placebo correctly still passes); forcing the fees window to
all-time fails 5; letting the current month into the baseline fails 1; and
dropping the elapsed-day truncation fails 3.
siddharthd
eaf5d5ac66