2/5 refactor: assert TestGroup directly in algorithm tests#121
Open
vokracko wants to merge 2 commits intojerry-git:masterfrom
Open
2/5 refactor: assert TestGroup directly in algorithm tests#121vokracko wants to merge 2 commits intojerry-git:masterfrom
vokracko wants to merge 2 commits intojerry-git:masterfrom
Conversation
The previous setup relied on pytest-cov (``--cov pytest_split --cov tests`` in addopts) which has a long-standing limitation when measuring a pytest plugin: the plugin imports happen during pytest's plugin discovery, *before* pytest-cov starts tracing. Anything that runs at import time (class bodies, decorators, type aliases, enum definitions) is reported as uncovered even though it obviously executed - the plugin wouldn't load otherwise. The ``CoverageWarning: Module pytest_split was previously imported, but not measured`` made that explicit. The cookiecutter template the project was generated from worked around this by adding ``--cov tests`` to the addopts, inflating the denominator with 100%-covered test files so the average reached 90%. That pulled the number up but stopped reporting the actual source coverage. Switch to ``coverage run -m pytest`` followed by ``coverage report``. Running ``coverage`` from the outside means tracing starts before Python imports anything at all, so plugin import-time code is counted. Real source coverage jumps from ~74% to 99%; threshold goes from 90 to 95 to reflect that.
Tests previously asserted each TestGroup field separately (`first.selected`, `first.deselected`, `first.duration`). Consolidate to a single equality check against an expected TestGroup, with concrete values for every field rather than only ``selected``.
This was referenced Apr 29, 2026
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Second of five stacked PRs that fix #25. The end goal is to extend stable group membership (already true for
least_durationsince 0.8.0) toduration_based_chunks. This PR is preparation: it makes test assertions easier to evolve as later PRs change algorithm output.Motivation. The downstream PRs change algorithm output ordering and add new fields to verify (durations, deselected lists). The existing per-attribute style would either need lots of new lines per assertion or would obscure mismatches when only one field is wrong. Consolidating to whole-
TestGroupequality up-front means every later PR adds value to the same assertion shape.What changes. Tests in
tests/test_algorithms.pypreviously asserted eachTestGroupfield separately:After:
Concrete values for every field, not just
selected.Stack.
coverage run→ 1/5 build: measure coverage on source only via coverage run #120TestGroupdirectlyduration_based_chunks— closes Splits invalid when collection order not deterministic #25 → 5/5 fix: stabilise duration_based_chunks across collection orders #124