perf: don't open new connections for test_get_table_schema

This means, however, that all queries need to undo any connection-
level state changes.

Author: lidavidm

adbc_drivers_validation/tests/query.py

@@ -19,8 +19,6 @@
 pytest_generate_tests hook, call generate_tests.
 """
 
-import typing
-
 import adbc_driver_manager.dbapi
 import pyarrow
 import pytest
@@ -140,35 +138,34 @@ def test_execute_schema(
     def test_get_table_schema(
         self,
         driver: model.DriverQuirks,
-        conn_factory: typing.Callable[[], adbc_driver_manager.dbapi.Connection],
+        conn: adbc_driver_manager.dbapi.Connection,
         query: model.Query,
     ) -> None:
         subquery = query.query
 
         expected_schema = subquery.expected_schema()
 
-        with conn_factory() as conn:
-            with setup_connection(query, conn):
-                _setup_query(driver, conn, query)
-
-                table_name = None
-                md = query.metadata()
-                table_name = md.setup.drop
-                if not table_name and isinstance(subquery, model.SelectQuery):
-                    # XXX: rather hacky, but extract the table name from the SELECT query
-                    # that would normally be executed
-                    query_str = subquery.query().split()
-                    for i, word in enumerate(query_str):
-                        if word.upper() == "FROM":
-                            table_name = query_str[i + 1]
-                            break
-
-                assert table_name, "Could not determine table name"
-
-                schema = conn.adbc_get_table_schema(table_name)
-                # Ignore the first column which is normally used to sort the table
-                schema = pyarrow.schema(list(schema)[1:])
-                compare.compare_schemas(expected_schema, schema)
+        with setup_connection(query, conn):
+            _setup_query(driver, conn, query)
+
+            table_name = None
+            md = query.metadata()
+            table_name = md.setup.drop
+            if not table_name and isinstance(subquery, model.SelectQuery):
+                # XXX: rather hacky, but extract the table name from the SELECT query
+                # that would normally be executed
+                query_str = subquery.query().split()
+                for i, word in enumerate(query_str):
+                    if word.upper() == "FROM":
+                        table_name = query_str[i + 1]
+                        break
+
+            assert table_name, "Could not determine table name"
+
+            schema = conn.adbc_get_table_schema(table_name)
+            # Ignore the first column which is normally used to sort the table
+            schema = pyarrow.schema(list(schema)[1:])
+            compare.compare_schemas(expected_schema, schema)
 
     def test_show_queries(
         self,

adbc_drivers_validation/utils.py

@@ -74,6 +74,11 @@ def setup_connection(
         options[key] = value.apply
         if revert := value.revert:
             options_revert[key] = revert
+        else:
+            warnings.warn(
+                f"No revert value for connection option {key} in {query.name}, this will likely have unexpected side effects!",
+                DeprecationWarning,
+            )
 
     conn.adbc_connection.set_options(**options)
     yield