feat: add PyArrow support to comparator

[aseembits93]

Summary

• Add comparison support for PyArrow types (Table, RecordBatch, Array, ChunkedArray, Scalar, Schema, Field, DataType)
• Add pyarrow>=15.0.0 to test dependencies
• Add comprehensive tests for all PyArrow type comparisons

Test plan

• All 149 comparator tests pass
• New PyArrow tests cover equality and inequality for all supported types
• Existing pandas tests still pass (verified pyarrow checks don't interfere)

🤖 Generated with Claude Code

[claude]

PR Review Summary

Prek Checks

✅ Passed (after auto-fix)

• Fixed 4 RUF100 (unused-noqa) errors in codeflash/verification/comparator.py — removed unused # noqa: PGH003 comments from numba imports
• Committed and pushed as style: auto-fix linting issues

Mypy

⚠️ Pre-existing issues only — no new mypy errors introduced by this PR

• comparator.py: 27 errors (all no-any-return from comparing Any-typed objects — pre-existing pattern throughout the file)
• test_comparator.py: ~400 errors (all no-untyped-def — missing return type annotations on test methods, standard for test files)

Code Review

✅ No critical issues found

The PR adds pyarrow type support to the comparator function, following the existing pattern used for numpy, pandas, scipy, torch, etc.:

• Correct placement: pyarrow checks are placed after scipy sparse and before pandas, avoiding type overlap issues
• Type coverage: Handles Table, RecordBatch, ChunkedArray, Array, Scalar, Schema, Field, DataType
• Null handling: Scalar null values are handled explicitly via is_valid checks before calling equals()
• bool() wrapping: Applied consistently to equals() calls, including fixing the pre-existing pandas equals() return (line 408)
• Lazy import: pyarrow is imported conditionally inside the HAS_PYARROW guard, consistent with other optional dependencies
• Good test coverage design: test_pyarrow() tests equality, inequality, type mismatches, nulls, nested types, and list arrays

Test Coverage

File	Stmts (main)	Stmts (PR)	Coverage (main)	Coverage (PR)	Delta
codeflash/verification/comparator.py	341	378	62%	56%	-6%

Note: The coverage decrease is due to the new pyarrow code paths (37 new statements) not being exercised in this test environment — pyarrow is in the tests dependency group but was not installed in the CI runner. The test_pyarrow test is correctly skipped via pytest.skip() when pyarrow is unavailable. When pyarrow IS installed, the test exercises all new code paths (Table, RecordBatch, Array, ChunkedArray, Scalar, Schema, Field, DataType — both equality and inequality). No actual coverage regression on existing code.

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Last updated: 2026-02-11