TEST: Reduce redundant numerical test matrices

[vyasr]

Description

Replace covariance/correlation’s redundant operand Cartesian product with nine explicit representative pairs, and remove an unused parameter from one masked-binary execution test.

Coverage accounting

• The pairs retain normal and integer inputs, constant and all-null values, nullable arrays, Arrow input, empty input, and singleton input.
• The indexed-Series pair uses the same three labels in a different order on both sides, retaining multi-row index-alignment behavior rather than only a singular/NaN outcome.
• The same pairs run for covariance and both Pearson and Spearman correlation (189 items to 27).
• The removed extension-compilation type parameter was not consumed by the test: every former node executed the same integer-scalar kernel.

Checklist

• I am familiar with the CONTRIBUTING.md guidelines.
• New or existing tests cover these test-only changes.
• Documentation updates are not needed.

[copy-pr-bot]

Auto-sync is disabled for draft pull requests in this repository. Workflows must be run manually.

Contributors can view more details about this message here.

[vyasr]

/ok to test

[vyasr]

/ok to test

[vyasr]

/ok to test

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Enterprise

Run ID: 5bd89779-3692-4931-807b-91898f72b0d9

📥 Commits

Reviewing files that changed from the base of the PR and between a8ad204 and e111ba5.

📒 Files selected for processing (2)

• python/cudf/cudf/tests/private_objects/test_extension_compilation.py
• python/cudf/cudf/tests/series/methods/test_cov_corr.py

Included review availability: Your plan provides up to 12 included reviews per hour; 11 remain after this review.

---

📝 Summary

Summary by CodeRabbit

• Tests
  • Simplified masked binary operation test parameters.
  • Consolidated covariance and correlation tests around shared paired test data.
  • Expanded named test scenarios covering nullable, Arrow-backed, indexed, empty, singleton, and reversed-type inputs.

Walkthrough

The changes revise covariance and correlation test inputs to use shared paired cases and simplify masked binary test parameterization by removing numeric type variation.

Changes

Covariance and correlation test data

Layer / File(s)	Summary
Shared covariance and correlation inputs python/cudf/cudf/tests/series/methods/test_cov_corr.py	Adds named paired input cases for covariance and correlation tests. Updates the correlation test to use the shared data set and updates the SPDX attribution.

Masked binary test parameters

Layer / File(s)	Summary
Masked binary parameter simplification python/cudf/cudf/tests/private_objects/test_extension_compilation.py	Removes the numeric type parameter from test_execute_masked_binary.

Priority: ⬇️ Low

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

Merge Risk: ⚪ Minimal · up to e111b

This change reduces redundant covariance, correlation, and masked-binary test parameterization while preserving the represented behavior cases. No current merge-blocking risk is identified.

Suggested reviewers: mroeschke

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 4 functions across 2 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly summarizes the main change: reducing redundant numerical test matrices. It is concise and related to the changeset.
Description check	✅ Passed	The description accurately explains the reduced covariance and correlation test matrix and the removal of the unused parameter.
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.

• Fix all pre-merge checks with AI

✨ Finishing Touches 💡 1

🛠️ Fix failing CI checks 💡

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

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