Skip polars tests relying on newer sqlite features

[TomAugspurger]

Description

Some polars tests are failing on nightly CI, which runs with both latest and our earliest-supported dependencies. Some of the polars tests uses sqlite features not available with the Python / sqlite used in our earliest-supported matrix.

This checks the sqlite version and skips the problematic tests when it's too old.

Note that CI doesn't run polars tests with earliest-supported, so a passing test here doesn't necessarily mean we fixed everything.

Closes #22850

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Enterprise

Run ID: 02e65cf3-2a49-4959-a372-ca01c7aa50ec

📥 Commits

Reviewing files that changed from the base of the PR and between f566057 and 0514c0e.

📒 Files selected for processing (1)

• python/cudf_polars/cudf_polars/testing/inject_gpu_engine.py

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📝 Walkthrough

Summary by CodeRabbit

• Tests
  • Enhanced GPU-engine testing plugin with runtime SQLite version detection. Automatically skips incompatible SQL filter-clause and string-aggregation tests on systems with SQLite 3.44.0 or earlier to prevent syntax errors during test execution.

Walkthrough

The pytest GPU-engine injection plugin now conditionally skips specific string-aggregation and filter-clause tests when running with SQLite versions <= 3.44.0. This addresses OperationalError syntax errors in earlier SQLite versions. The implementation adds version detection imports, updates the skip-list type annotation, and applies a runtime version gate to update the skip list.

Changes

SQLite Version-Based Test Skip Logic

Layer / File(s)	Summary
SQLite version-conditional test skip mechanism python/cudf_polars/cudf_polars/testing/inject_gpu_engine.py	Imports sqlite3 and packaging.version for version detection; updates TESTS_TO_SKIP type from Mapping[str, str] to dict[str, str]; conditionally appends multiple SQL filter-clause and string-aggregation test identifiers to the skip list when SQLite is version <= 3.44.0.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

Possibly related PRs

• rapidsai/cudf#22605: Both PRs modify TESTS_TO_SKIP skip-list entries in the GPU-engine injection plugin; this PR adds SQLite-version-based skips while the retrieved PR removes or edits specific skips.

Suggested labels

Python, cudf-polars, non-breaking, improvement

Suggested reviewers

• nirandaperera
• vyasr

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately describes the main change: adding logic to skip polars tests that rely on newer SQLite features when running against older SQLite versions.
Description check	✅ Passed	The description is clearly related to the changeset, explaining why the tests need to be skipped and how the fix addresses the issue reported in #22850.
Linked Issues check	✅ Passed	The PR successfully addresses the objective from issue #22850 by implementing SQLite version checking to skip tests relying on newer SQLite features (STRING_AGG, GROUP_CONCAT with ORDER BY syntax).
Out of Scope Changes check	✅ Passed	All changes are directly related to addressing the linked issue: adding SQLite version checks and conditionally skipping problematic tests with no unrelated modifications.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[Matt711]

Presumably this would fail with polars CPU and should be fixed there?

[TomAugspurger]

Correct. I opted not to open an issue since sqlite3 is a bit of an odd dependency (typically, though not always bundled with Python).

[TomAugspurger]

/merge