test(python): cover arithmetic with distance projections (#3862)

## Summary

- add Python regression coverage for integer and double arithmetic
against the generated _distance column
- merge the current main base containing Lance v11.0.0-beta.3 from #3896
- verify both expressions retain the generated scoring field Float32
type and compute the expected values

## Root cause

Lance parsed dynamic projection expressions before vector search added
its generated Float32 _distance field. Without a typed provisional
field, expression discovery rejected mixed numeric arithmetic. Lance
upstream fixed discovery and final-schema replanning in
lance-format/lance#8163, and the current base consumes that fix through
Lance v11.0.0-beta.3.

## Validation

- uv run --extra tests pytest
python/tests/test_query.py::test_select_arithmetic_with_distance -vv
--maxfail=2 — 2 passed
- python/.venv/bin/ruff format --check python/python/tests/test_query.py
- python/.venv/bin/ruff check .

Fixes #2618

<!-- lance-gatekeeper-fix:v1 agent=816a060090517471edfb73652bb5c9fe
generation=1 -->

---------

Co-authored-by: Gatefixer <313497061+lancedb-gatefixer[bot]@users.noreply.github.com>
Co-authored-by: Xuanwo <github@xuanwo.io>
This commit is contained in:
lancedb-gatefixer[bot]
2026-08-27 17:10:51 +08:00
committed by GitHub
parent d24b2dcacc
commit 0dd9dfdfc7
+15
View File
@@ -675,6 +675,21 @@ def test_distance_range(table: lancedb.table.Table):
assert res["_distance"].to_pylist() == [min_dist, max_dist]
@pytest.mark.parametrize("expression", ["1 - _distance", "1.0 - _distance"])
def test_select_arithmetic_with_distance(table, expression):
result = (
table.search([10, 10])
.select({"similarity": expression, "_distance": "_distance"})
.distance_type("cosine")
.to_arrow()
)
assert result.schema.field("similarity").type == pa.float32()
assert result["similarity"].to_pylist() == pytest.approx(
[1 - distance for distance in result["_distance"].to_pylist()]
)
@pytest.mark.asyncio
async def test_distance_range_async(table_async: AsyncTable):
q = [0, 0]