add system tests and fix pandas warning

Author: tswast

bigframes/dataframe.py

@@ -4419,7 +4419,7 @@ def to_dict(
         allow_large_results: Optional[bool] = None,
         **kwargs,
     ) -> dict | list[dict]:
-        return self.to_pandas(allow_large_results=allow_large_results).to_dict(orient, into, **kwargs)  # type: ignore
+        return self.to_pandas(allow_large_results=allow_large_results).to_dict(orient=orient, into=into, **kwargs)  # type: ignore
 
     def to_excel(
         self,

tests/system/small/session/test_read_gbq_query.py

@@ -0,0 +1,113 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import datetime
+
+import pytest
+
+import bigframes
+import bigframes.core.nodes as nodes
+
+
+def test_read_gbq_query_w_allow_large_results(session: bigframes.Session):
+    if not hasattr(session.bqclient, "default_job_creation_mode"):
+        pytest.skip("Jobless query only available on newer google-cloud-bigquery.")
+
+    query = "SELECT 1"
+
+    # Make sure we don't get a cached table.
+    configuration = {"query": {"useQueryCache": False}}
+
+    # Very small results should wrap a local node.
+    df_false = session.read_gbq(
+        query,
+        configuration=configuration,
+        allow_large_results=False,
+    )
+    assert df_false.shape == (1, 1)
+    roots_false = df_false._get_block().expr.node.roots
+    assert any(isinstance(node, nodes.ReadLocalNode) for node in roots_false)
+    assert not any(isinstance(node, nodes.ReadTableNode) for node in roots_false)
+
+    # Large results allowed should wrap a table.
+    df_true = session.read_gbq(
+        query,
+        configuration=configuration,
+        allow_large_results=True,
+    )
+    assert df_true.shape == (1, 1)
+    roots_true = df_true._get_block().expr.node.roots
+    assert any(isinstance(node, nodes.ReadTableNode) for node in roots_true)
+
+
+def test_read_gbq_query_w_columns(session: bigframes.Session):
+    query = """
+    SELECT 1 as int_col,
+    'a' as str_col,
+    TIMESTAMP('2025-08-21 10:41:32.123456') as timestamp_col
+    """
+
+    result = session.read_gbq(
+        query,
+        columns=["timestamp_col", "int_col"],
+    )
+    assert list(result.columns) == ["timestamp_col", "int_col"]
+    assert result.to_dict(orient="records") == [
+        {
+            "timestamp_col": datetime.datetime(
+                2025, 8, 21, 10, 41, 32, 123456, tzinfo=datetime.timezone.utc
+            ),
+            "int_col": 1,
+        }
+    ]
+
+
+@pytest.mark.parametrize(
+    ("index_col", "expected_index_names"),
+    (
+        pytest.param(
+            "my_custom_index",
+            ("my_custom_index",),
+            id="string",
+        ),
+        pytest.param(
+            ("my_custom_index",),
+            ("my_custom_index",),
+            id="iterable",
+        ),
+        pytest.param(
+            ("my_custom_index", "int_col"),
+            ("my_custom_index", "int_col"),
+            id="multiindex",
+        ),
+    ),
+)
+def test_read_gbq_query_w_index_col(
+    session: bigframes.Session, index_col, expected_index_names
+):
+    query = """
+    SELECT 1 as int_col,
+    'a' as str_col,
+    0 as my_custom_index,
+    TIMESTAMP('2025-08-21 10:41:32.123456') as timestamp_col
+    """
+
+    result = session.read_gbq(
+        query,
+        index_col=index_col,
+    )
+    assert tuple(result.index.names) == expected_index_names
+    assert frozenset(result.columns) == frozenset(
+        {"int_col", "str_col", "my_custom_index", "timestamp_col"}
+    ) - frozenset(expected_index_names)

tests/system/small/test_session.py

@@ -33,7 +33,6 @@
 import pytest
 
 import bigframes
-import bigframes.core.nodes as nodes
 import bigframes.dataframe
 import bigframes.dtypes
 import bigframes.ml.linear_model
@@ -641,37 +640,6 @@ def test_read_gbq_with_configuration(
     assert df.shape == (9, 3)
 
 
-def test_read_gbq_query_w_allow_large_results(session: bigframes.Session):
-    if not hasattr(session.bqclient, "default_job_creation_mode"):
-        pytest.skip("Jobless query only available on newer google-cloud-bigquery.")
-
-    query = "SELECT 1"
-
-    # Make sure we don't get a cached table.
-    configuration = {"query": {"useQueryCache": False}}
-
-    # Very small results should wrap a local node.
-    df_false = session.read_gbq(
-        query,
-        configuration=configuration,
-        allow_large_results=False,
-    )
-    assert df_false.shape == (1, 1)
-    roots_false = df_false._get_block().expr.node.roots
-    assert any(isinstance(node, nodes.ReadLocalNode) for node in roots_false)
-    assert not any(isinstance(node, nodes.ReadTableNode) for node in roots_false)
-
-    # Large results allowed should wrap a table.
-    df_true = session.read_gbq(
-        query,
-        configuration=configuration,
-        allow_large_results=True,
-    )
-    assert df_true.shape == (1, 1)
-    roots_true = df_true._get_block().expr.node.roots
-    assert any(isinstance(node, nodes.ReadTableNode) for node in roots_true)
-
-
 def test_read_gbq_with_custom_global_labels(
     session: bigframes.Session, scalars_table_id: str
 ):