Address Copilot review feedback on the cache PR:
* Split collect_tests into _collect_tests_uncached (the original
directory-based pre-cache flow) and _collect_tests_cached (walks
the tree to build per-file hashes). Without --cache we now skip
the walk + per-file hash entirely.
* A single-file root has no ancestor conftests to walk, so the
conftest_hash would always be empty and stale counts could survive
a real conftest change; bypass the cache for the file-root case.
* Save the cache file with explicit utf-8 encoding and
ensure_ascii=False.
Persist the result of pytest --collect-only between CI runs as a JSON
file keyed by content hash, so unchanged test files are served from
cache and only edited or new files are re-collected. The cache is
self-healing:
* Missing, corrupt, or wrong-version files fall back to a full collect.
* Any conftest.py change anywhere under the test root invalidates the
whole cache, so fixture parametrization shifts cannot silently skew
counts.
* Files pytest returns nothing for (helper modules named test_*.py with
no test functions) are cached as zero so they don't get re-collected
forever.
Walking is done once with os.walk (~2x faster than Path.rglob) and
collects test files plus conftests in a single pass. When the cache
is fully cold we feed pytest top-level directories rather than
thousands of file paths so cold runs stay as fast as before the cache
landed.
Wire the new --cache flag through the prepare-pytest-full job and back
the cache file with actions/cache so PRs can pick up the latest dev
snapshot via restore-keys. Local timings: cold 11s, warm with no diff
0.4s, warm with one file edited 2.3s.
Only pass directories and test_*.py files to pytest --collect-only so
helpers like tests/components/conftest.py and tests/components/common.py
are not treated as explicit collection targets, and bail out with a
clear error if no eligible paths are found instead of running pytest
with no arguments.
cProfile showed 99.6% of split_tests.py wall time was spent in the
single pytest --collect-only subprocess. Fan out the collection across
``os.cpu_count()`` workers; round-robin chunking keeps each batch
roughly equal, and tests/components is expanded one level deeper so
the ~1000 integration subdirectories distribute evenly. Local wall
time dropped from ~132s to ~11s on an 18-core box. Bucket output is
unchanged because we still parse the same pytest -qq output, just
aggregated from multiple invocations.
J. Nick Koston
J. Nick Koston
Joost Lekkerkerker
HoffmanEl
Mattias Arrelid
Penny Wood
Franck Nijhof
Raphael Hehl
mhuiskes
chiro79
Robert Resch
Kamil Breguła
Jan Čermák
Willem-Jan van Rootselaar
Adam Katic
Jonathan Segev
AlCalzone