ci: wire up Codecov uploads and update CODEOWNERS

[farhadrgh]

The Codecov app is installed but receives nothing. pyproject's pytest addopts already run --cov=nvsubquadratic --cov-report=term, so coverage is computed on every gpu-tests run and then discarded to the log.

Two things made this non-obvious. pytest runs inside the CI container via docker run --rm, so a report written in the container disappears with it — the coverage directory has to be a bind mount. And the image runs as USER ubuntu (Dockerfile:218), whose uid need not match the runner's, so the mount point is chmod 777 rather than relying on a uid match.

Only --cov-report=xml is added on the command line; --cov and the term report stay in pyproject so local runs are unchanged and CI logs keep the summary.

The upload is deliberately incapable of failing the job: continue-on-error plus fail_ci_if_error: false. gpu-tests is a required status check that takes ~36 minutes on a single self-hosted runner, and a Codecov outage or a missing CODECOV_TOKEN is not worth blocking a merge over. If the token secret is absent the action falls back to tokenless upload, which works for public repos.

Also gitignores the coverage/ directory the job creates in the workspace; .gitignore already covered .coverage and a bare coverage.xml but not the directory.

Summary

Environment setup

Create the conda environment (required to run tests):

bash setup_conda_env.sh
conda activate nvsubquadratic

Test plan

• pre-commit run --all-files passes (pre-commit install if not yet set up).
• Existing tests pass (pytest tests/).
• New tests added, or explain why not needed:

Documentation checklist

For every new or modified public symbol in nvsubquadratic/ or experiments/:

• Every new module has a module-level docstring explaining what it contains and why.
• Every new public class has a class docstring covering purpose, math/motivation, and key attributes.
• Every new public method / function has Args: and Returns: blocks with tensor shapes where applicable.
• Math notation is consistent with the paper (or a comment explains any deviation).
• Docstrings containing backslashes use r"""...""" (required by ruff D301).
• If a new file was added, a row has been added to docs-tracker.md with status [x].

See CONVENTIONS.md for the full style guide.

Summary by CodeRabbit

• Tests

  • GPU test runs now generate XML coverage reports.
  • Coverage results are uploaded automatically when available, while reporting issues remain non-blocking and do not prevent test completion.

• Chores

  • Generated coverage directories are now excluded from version control, keeping working trees and project changes cleaner.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Enterprise

Run ID: 7780fc62-6075-48c9-a539-544f5adec6cc

📥 Commits

Reviewing files that changed from the base of the PR and between c1884cb and 03e9ae3.

📒 Files selected for processing (1)

• .github/CODEOWNERS

Included review availability: Your plan provides up to 12 included reviews per hour; 9 remain after this review.

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📝 Walkthrough

Walkthrough

The GPU test workflow now generates an XML coverage report in a mounted directory and uploads it to Codecov without failing the workflow. Git ignores the coverage directory. CODEOWNERS now assigns owners to subquadratic-ops paths and tests.

Changes

GPU coverage reporting

Layer / File(s)	Summary
Coverage generation and upload .github/workflows/gpu-tests.yml, .gitignore	The GPU pytest step writes XML coverage output to a writable mounted directory. A non-blocking Codecov upload runs regardless of prior step status. The coverage/ directory is ignored by Git.

Subquadratic-ops ownership

Layer / File(s)	Summary
Ownership rules .github/CODEOWNERS	CODEOWNERS entries cover subquadratic-ops wrappers, lowering, modules, and related tests. The entries assign the default owners and an upstream maintainer.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Feature

Merge Risk: ⚪ Minimal · up to 03e9a

The PR adds non-blocking coverage reporting and ownership metadata without a supported merge-blocking behavior change.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 0…
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly identifies the two main changes: Codecov uploads and CODEOWNERS updates. It is concise and specific.
Description check	✅ Passed	The description provides a detailed summary, implementation rationale, environment setup, and relevant coverage behavior. The template remains partially incomplete: the Summary placeholder is unchange…

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch farhadr/codecov-upload

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