* chore(ci): refresh the shard duration baseline
backend/.test_durations was last regenerated on 2026-09-22 (61ae228b0, #5656)
and now covers 40.1% of the collected suite, so `least_duration` plans 19,415
tests from the imputed average instead of measured cost. Replaying CI's 4-way
split with the committed file yields shard loads of 203.5/217.4/234.3/222.9s
(1.15x heaviest-to-lightest); with this refresh the same replay is 219.6s each.
Regenerated with the documented target: `make test-shard-durations`, i.e.
`pytest -m "not live" --ignore=tests/blocking_io --store-durations
--clean-durations --durations-path=.test_durations tests/ -q` on main at
8d994cc1e. Data-only diff; the shard jobs keep reading the file unchanged.
* chore(ci): cover the four tests added by 6b60903d7
The checkpointer/postgres-schema helper suites gained 4 cases while this
refresh was in flight, which would have left the baseline 4 entries short of
the base tip. Re-ran just those two files through the same store path, so the
file now covers 32,396/32,396 collected tests with no gap. Re-measuring those
files also refreshed 113 neighbouring entries.
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Co-authored-by: Willem Jiang <willem.jiang@gmail.com>
* feat(ci): split backend unit tests into parallel CI shards
Split the single offline backend `make test` job into four GitHub Actions
matrix shards (SPLITS=4, GROUP=1..4) via pytest-split, so the ~12k-test suite
runs in parallel instead of in one 15-minute job. Each shard runs on its own
runner with its own Postgres/Redis services; fail-fast: false lets a failing
shard report its owned tests without cancelling its peers.
`make test` stays the canonical full-suite entry point; CI now calls the new
`make test-shard SPLITS=4 GROUP=N`. tests/blocking_io remains owned solely by
the dedicated blocking-I/O workflow (excluded via --ignore), extending #5105.
Fixes#5088
* test(ci): make backend test shards duration-aware and pin the contract
Make `make test-shard` an explicit least_duration split that READS
backend/.test_durations (read-only for shards, so concurrent CI jobs never
race writes on it), and add `make test-shard-durations` to regenerate that
file from the full offline suite. Update the CI unit-test workflow contract to
call `make test-shard SPLITS=4 GROUP=<n>` and assert the shard command carries
--splits 4, --group 2, -m "not live", --ignore=tests/blocking_io and
--splitting-algorithm least_duration. Verified on the real 13,140-test normal
suite that the four shards are pairwise disjoint and their union equals the
unsplit suite.
Refs #5088
* test(ci): fail fast when the duration baseline is missing
`make test-shard` now requires backend/.test_durations and exits with a clear
error instead of letting pytest-split silently degrade to an even (count-based)
split. Harden the CI contract test to pin `--durations-path=.test_durations` and
to assert the repo ships the committed duration baseline.
Refs #5088
* docs: trim backend/AGENTS.md within guidance budget
* test(ci): add backend test duration baseline
Add the duration baseline generated by a full offline backend run on a
GitHub-hosted ubuntu-latest runner (the same runner type the shards use), so
`make test-shard` balances the four matrix shards by real wall-clock cost.
Refs #5088
* test(ci): make the duration writer honor DURATIONS_FILE
`test-shard-durations` now writes `--durations-path=$(DURATIONS_FILE)` instead of a
hard-coded .test_durations, so the reader and writer stay consistent when the
path is overridden.
Refs #5088
* test(ci): address sharding review feedback
* test: isolate subagent execution capacity state
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Co-authored-by: Willem Jiang <willem.jiang@gmail.com>
