Two requests can probe the same workout, both find no heart-rate series,
and both mean to attach one. The unique index on `workout_id` picks a
winner; the loser has to report the duplicate it turned out to be rather
than claim an attach the database never made. Nothing could catch that
arm going wrong: the unit fake echoes every row back as landed, and the
race suite carries no series at all, so replacing the status with a
constant `enriched` left the whole suite green. Two concurrent posts of
the same enrichment now assert one `enriched` against one `duplicate`
and a single stored series.
The published contract also says now what the counters mean, instead of
leaving it in a comment: an entry reported as `enriched` counts towards
`duplicates`, because the top-level counters count workout rows and an
enrichment writes none. Field descriptions on the response and on the
per-entry status and reason, OpenAPI regenerated.
Two entries carrying the same external id and both a `samples` array
reached the enrichment arm one after the other, and both read the same
landed workout id back, so the response claimed two attaches where the
database had written one. The second entry now takes the duplicate arm:
a workout is claimed by the first entry of the batch that reaches it.
A batch entry matching a stored workout stays first-write-wins for the
workout row. What it can do now is hand over a heart-rate series the
stored workout does not have yet: the series is attached, the row itself
is not written at all, and the entry reports back as `enriched`. A
workout that already carries a series is a no-op, so a client can walk
its whole history as often as it likes.
- The pre-flight probe now answers both questions at once, whether the
row exists and whether it already has a series, and carries the id so
the attach addresses the stored workout without a second round trip.
- The attach rides the same child write as a fresh workout's series.
RETURNING names the rows that landed, so a workout that gained a
series between probe and write reports as the duplicate it is instead
of claiming an attach that never happened.
- A `samples` array that fails validation is refused per entry with
`reason: "invalid_samples"` rather than failing the batch. One
unusable session out of a hundred must not stall a history sweep the
client cannot repair by retrying; every other validation failure keeps
failing the batch.
- The wide event and the audit row tally enrichments. Counts only, the
series never reaches either.
- `enriched` is the one contract movement: additive on the per-entry
status, request shape unchanged. OpenAPI regenerated.
Integration coverage against a real Postgres pins the attach, the
repeat as a no-op, the refusal of a bad series alongside entries that
land, a mixed batch reporting each status, and the stored workout row
compared whole before and after, `updated_at` included.
Marc-André Bombeck