test: Add new_streaming

[luke396]

What type of PR is this? (check all applicable)

• 💾 Refactor
• ✨ Feature
• 🐛 Bug Fix
• 🔧 Optimization
• 📝 Documentation
• ✅ Test
• 🐳 Other

Related issues

• Related issue #<issue number>
• Closes test: run test suite with new_streaming=True for Polars lazy #1875

Checklist

• Code follows style guide (ruff)
• Tests added
• Documented the changes

If you have comments or can explain your changes, please do so below

[MarcoGorelli]

Thanks @luke396 ! Can we also set this environment variable for at least one CI run?

[MarcoGorelli]

thanks, now we see a couple of test failures

FAILED tests/expr_and_series/reduction_test.py::test_scalar_reduction_with_columns[polars[lazy]-0] - ValueError: left len(left)=1 != right len(right)=3
FAILED tests/group_by_test.py::test_group_by_categorical[polars[lazy]] - pyo3_runtime.PanicException: called `Option::unwrap()` on a `None` value

the first will be fixed in the upcoming polars release

the second we may need to xfail

[luke396]

the first will be fixed in the upcoming polars release

the second we may need to xfail

Thanks for the explanation! I'll address the second point shortly.

Looks like we should merge this PR once Polars' new release is out!