feat(python): support .rerank() on non-hybrid queries in Async API (WIP) (#1972)

Fixes https://github.com/lancedb/lancedb/issues/1950

---------

Co-authored-by: Renato Marroquin <renato.marroquin@oracle.com>

python/python/tests/test_query.py

@@ -6,14 +6,18 @@ from datetime import timedelta
 from pathlib import Path
 
 import lancedb
-from lancedb.index import IvfPq
+from lancedb.index import IvfPq, FTS
 import numpy as np
 import pandas.testing as tm
 import pyarrow as pa
 import pytest
 import pytest_asyncio
 from lancedb.pydantic import LanceModel, Vector
-from lancedb.query import AsyncQueryBase, LanceVectorQueryBuilder, Query
+from lancedb.query import (
+    AsyncQueryBase,
+    LanceVectorQueryBuilder,
+    Query,
+)
 from lancedb.table import AsyncTable, LanceTable
 
 
@@ -47,6 +51,7 @@ async def table_async(tmp_path) -> AsyncTable:
             "id": pa.array([1, 2]),
             "str_field": pa.array(["a", "b"]),
             "float_field": pa.array([1.0, 2.0]),
+            "text": pa.array(["a", "dog"]),
         }
     )
     return await conn.create_table("test", data)
@@ -314,7 +319,7 @@ async def test_query_async(table_async: AsyncTable):
     await check_query(
         table_async.query(),
         expected_num_rows=2,
-        expected_columns=["vector", "id", "str_field", "float_field"],
+        expected_columns=["vector", "id", "str_field", "float_field", "text"],
     )
     await check_query(table_async.query().where("id = 2"), expected_num_rows=1)
     await check_query(
@@ -383,32 +388,42 @@ async def test_query_async(table_async: AsyncTable):
         expected_columns=["id", "vector", "_rowid"],
     )
 
+    # FTS with rerank
+    await table_async.create_index("text", config=FTS(with_position=False))
+    await check_query(
+        table_async.query().nearest_to_text("dog").rerank(),
+        expected_num_rows=1,
+    )
+
+    # Vector query with rerank
+    await check_query(table_async.vector_search([1, 2]).rerank(), expected_num_rows=2)
+
 
 @pytest.mark.asyncio
 async def test_query_to_arrow_async(table_async: AsyncTable):
     table = await table_async.to_arrow()
     assert table.num_rows == 2
-    assert table.num_columns == 4
+    assert table.num_columns == 5
 
     table = await table_async.query().to_arrow()
     assert table.num_rows == 2
-    assert table.num_columns == 4
+    assert table.num_columns == 5
 
     table = await table_async.query().where("id < 0").to_arrow()
     assert table.num_rows == 0
-    assert table.num_columns == 4
+    assert table.num_columns == 5
 
 
 @pytest.mark.asyncio
 async def test_query_to_pandas_async(table_async: AsyncTable):
     df = await table_async.to_pandas()
-    assert df.shape == (2, 4)
+    assert df.shape == (2, 5)
 
     df = await table_async.query().to_pandas()
-    assert df.shape == (2, 4)
+    assert df.shape == (2, 5)
 
     df = await table_async.query().where("id < 0").to_pandas()
-    assert df.shape == (0, 4)
+    assert df.shape == (0, 5)
 
 
 @pytest.mark.asyncio