TEST: Focus concat join coverage

[vyasr]

Description

Focus concat join coverage on representative Series and empty-DataFrame inputs. The curated cases retain join, axis, sort, ignore-index, schema, and empty-input behavior without repeating equivalent combinations.

Checklist

• I am familiar with the Contributing Guidelines.
• 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

[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: 0ba819c9-b1de-4969-90ed-f34b1288b335

📥 Commits

Reviewing files that changed from the base of the PR and between 34f116a and 38a18df.

📒 Files selected for processing (1)

• python/cudf/cudf/tests/reshape/test_concat.py

Included review availability: Your plan provides up to 12 included reviews per hour; 7 remain after this review.

---

📝 Summary

Summary by CodeRabbit

• Tests
  • Updated empty-dataframe concatenation test cases to validate matching dataframe combinations without unrelated parameter combinations.
  • Adjusted column names used in axis-1 concatenation test scenarios.

Walkthrough

The concat tests now define paired df and other inputs for axis-0 and axis-1 cases. The updated cases retain empty, indexed, categorical, numeric, and heterogeneous dataframe combinations without generating Cartesian products.

Changes

Concat test coverage

Layer / File(s)	Summary
Axis-0 paired inputs python/cudf/cudf/tests/reshape/test_concat.py	Axis-0 tests use paired dataframe cases for representative concat combinations.
Axis-1 paired inputs python/cudf/cudf/tests/reshape/test_concat.py	Axis-1 tests use paired dataframe cases and update selected fixture column names.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~15 minutes

Merge Risk: ⚪ Minimal · up to 38a18

This updates concat test inputs to use representative paired DataFrame cases without changing runtime behavior. No current merge-blocking risk is identified.

Suggested reviewers: mroeschke, galipremsagar, bdice

🚥 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 2 functions across 1 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 identifies focused concat join test coverage, which matches the primary changes.
Description check	✅ Passed	The description accurately summarizes the curated concat test coverage and the removal of equivalent combinations.
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.}

[vyasr]

/ok to test

[vyasr]

/merge