test(metrics): add coverage for metrics timing decorator

[mnadzam]

Closes #978

[coderabbitai]

📝 Walkthrough

Walkthrough

Adds tests/tests_metrics.py (new) which provides pytest coverage for fromager.metrics. It defines several functions decorated with @metrics.timeit to exercise timing storage and descriptions on a provided context.WorkContext, asserting that timing entries are written to tmp_context.time_store only when both a requirement and a resolvable version source exist (explicit version arg or Version in the return). Tests verify descriptions stored in tmp_context.time_description_store, that original return values are preserved, that exceptions propagate without writing timing data, that metrics.summarize() logs expected INFO output when data exists and none when empty, and unit-tests _extract_version_from_return() across None, Version, tuples, and non-iterable inputs.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~15 minutes

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately describes the primary change: adding pytest coverage for the metrics timing decorator.
Description check	✅ Passed	The description references issue #978, which directly relates to the PR's objective of adding test coverage for metrics.py.
Linked Issues check	✅ Passed	The PR implements all four acceptance criteria from #978: timeit() timing storage, timeit() exception propagation, summarize() logging, and _extract_version_from_return() behavior across variants.
Out of Scope Changes check	✅ Passed	All changes are scoped to test coverage for metrics.py as required; no unrelated modifications to source code or other modules detected.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[coderabbitai]

Actionable comments posted: 2

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@tests/test_metrics.py`:
- Around line 128-144: Add a new unit test in tests/test_metrics.py that calls
metrics._extract_version_from_return(None) and asserts it returns None to cover
the acceptance criterion for issue `#978`; ensure the test function name is unique
(e.g., test_extract_version_none) and follows the same style as the other tests
so it runs with the existing test suite and exercises the code path where
iterating over None would raise a TypeError.
- Around line 31-37: The helper function _test_raises used under the
metrics.timeit decorator must accept a version parameter so the decorator's
storage path (which only runs when both req and version are present) can be
exercised; update the _test_raises signature to include version: str | None =
None (or the project's Version type if different) and ensure the function
accepts and ignores this parameter while still raising the RuntimeError so the
test can pass a version and verify that exceptions prevent storage.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 5f0dfdb8-5fec-4664-9c4e-b7c1d569f8bc

📥 Commits

Reviewing files that changed from the base of the PR and between aec9c9c and 59b813f.

📒 Files selected for processing (1)

• tests/test_metrics.py

[rd4398]

LGTM

[mergify]

Tick the box to add this pull request to the merge queue (same as @mergifyio queue).

• Queue this pull request

[mergify]

queue

⚠️ Configuration not compatible with a branch protection setting

Details

The branch protection setting Require branches to be up to date before merging is not compatible with draft PR checks. To keep this branch protection enabled, update your Mergify configuration to enable in-place checks: set merge_queue.max_parallel_checks: 1, set every queue rule batch_size: 1, and avoid two-step CI (make merge_conditions identical to queue_conditions). Otherwise, disable this branch protection.

[mergify]

Tick the box to add this pull request to the merge queue (same as @mergifyio queue).

• Queue this pull request