testing

Unit tests

Vitest, tests/**/*.test.ts. Unit tests protect the deterministic core; the observable behavior of the product is protected by the Gherkin specs in features/ (see @bdd-specs.mdc). Write the spec first, the unit test second, the code third.

Layout and naming

• File: tests/<module>.test.ts, mirroring the module under test.
• describe('<module or function>'), it('<observable behavior>'). The sentence in it reads as a fact: it('pulls check-in one day earlier for a morning event').
• Arrange / Act / Assert, in that order, with a blank line between the blocks.
• One behavior per test. A test that asserts four unrelated things hides which one broke.

What is unit tested

The pure layer, exhaustively. Everything in src/composer/ that has no I/O, plus payload normalization in src/sources/ and the cache key builder.

The mandatory set, from specs/08-repozitoriy.md; each one is a real defect that has been observed or is one payload away:

1. An online event builds no trip.
2. An empty or unrecognized venue yields no precise marker.
3. Check-in is one day before start_date for a morning event.
4. An event finishing late adds one more night.
5. Arrival after starts_at minus 60 minutes is flagged and cannot be the primary package.
6. The hotel price is not multiplied by the number of nights (price_basis: "stay_total").
7. The total price includes both the outbound and the return leg.
8. A hotel geo_id is never taken from a transport response.
9. A hotel checkout built without offerpack_hash is not labelled a cart.
10. Equivalent argument shapes produce one cache key.
11. A partial transport-mode failure is not turned into "there is no such transport".
12. A free-text event price stays out of the sum.

Twelve more that the plan review surfaced, each a defect one payload away:

1. An ISO time with an offset is compared on the right calendar day: 11:59+03:00 must not cross noon or slide to the neighbouring date on the way through UTC.
2. Zero nights is a legal answer and produces a hotel-less package, not a forced night.
3. Every tie in the three package rules is broken by a stable secondary key.
4. Working days burnt differ between a night departure and a midday one, so "Без отпуска" does not collapse into "Дешевле всего".
5. "от 7 000 ₽" parses as a lower bound and the total is labelled as one.
6. The cache does not store a rejected promise, coalesces identical in-flight requests and respects its size ceiling.
7. trip_id round-trips Cyrillic, sorts its keys canonically, and rejects a corrupted string, an unknown version and one over the length ceiling.
8. Every string from a source is escaped in text, in attributes, in URLs and inside the embedded JSON.
9. A walking time is never derived from an OSRM car-profile answer.
10. A total assembled without a hotel is not called the full participation price.
11. Empty sets: no return leg, no hotel, no feasible pair at all.
12. In replay the reference date is the fixture's recorded_at, not the wall clock.