test: Engine tests for selection ops (#1800)

Author: TrevorBergeron

tests/system/small/engines/conftest.py

@@ -19,7 +19,7 @@
 import pytest
 
 import bigframes
-from bigframes.core import local_data
+from bigframes.core import ArrayValue, local_data
 from bigframes.session import (
     direct_gbq_execution,
     local_scan_executor,
@@ -62,6 +62,13 @@ def managed_data_source(
     return local_data.ManagedArrowTable.from_pandas(scalars_pandas_df_index)
 
 
+@pytest.fixture(scope="module")
+def scalars_array_value(
+    managed_data_source: local_data.ManagedArrowTable, fake_session: bigframes.Session
+):
+    return ArrayValue.from_managed(managed_data_source, fake_session)
+
+
 @pytest.fixture(scope="module")
 def zero_row_source() -> local_data.ManagedArrowTable:
     return local_data.ManagedArrowTable.from_pandas(pd.DataFrame({"a": [], "b": []}))

tests/system/small/engines/engine_utils.py

@@ -0,0 +1,31 @@
+# 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.
+
+from bigframes.core import nodes
+from bigframes.session import semi_executor
+
+
+def assert_equivalence_execution(
+    node: nodes.BigFrameNode,
+    engine1: semi_executor.SemiExecutor,
+    engine2: semi_executor.SemiExecutor,
+):
+    e1_result = engine1.execute(node, ordered=True)
+    e2_result = engine2.execute(node, ordered=True)
+    assert e1_result is not None
+    assert e2_result is not None
+    # Schemas might have extra nullity markers, normalize to node expected schema, which should be looser
+    e1_table = e1_result.to_arrow_table().cast(node.schema.to_pyarrow())
+    e2_table = e2_result.to_arrow_table().cast(node.schema.to_pyarrow())
+    assert e1_table.equals(e2_table), f"{e1_table} is not equal to {e2_table}"

tests/system/small/engines/test_read_local.py

@@ -16,29 +16,15 @@
 
 import bigframes
 from bigframes.core import identifiers, local_data, nodes
-from bigframes.session import polars_executor, semi_executor
+from bigframes.session import polars_executor
+from tests.system.small.engines.engine_utils import assert_equivalence_execution
 
 pytest.importorskip("polars")
 
 # Polars used as reference as its fast and local. Generally though, prefer gbq engine where they disagree.
 REFERENCE_ENGINE = polars_executor.PolarsExecutor()
 
 
-def ensure_equivalence(
-    node: nodes.BigFrameNode,
-    engine1: semi_executor.SemiExecutor,
-    engine2: semi_executor.SemiExecutor,
-):
-    e1_result = engine1.execute(node, ordered=True)
-    e2_result = engine2.execute(node, ordered=True)
-    assert e1_result is not None
-    assert e2_result is not None
-    # Schemas might have extra nullity markers, normalize to node expected schema, which should be looser
-    e1_table = e1_result.to_arrow_table().cast(node.schema.to_pyarrow())
-    e2_table = e2_result.to_arrow_table().cast(node.schema.to_pyarrow())
-    assert e1_table.equals(e2_table), f"{e1_table} is not equal to {e2_table}"
-
-
 def test_engines_read_local(
     fake_session: bigframes.Session,
     managed_data_source: local_data.ManagedArrowTable,
@@ -51,7 +37,7 @@ def test_engines_read_local(
     local_node = nodes.ReadLocalNode(
         managed_data_source, scan_list, fake_session, offsets_col=None
     )
-    ensure_equivalence(local_node, REFERENCE_ENGINE, engine)
+    assert_equivalence_execution(local_node, REFERENCE_ENGINE, engine)
 
 
 def test_engines_read_local_w_offsets(
@@ -69,7 +55,7 @@ def test_engines_read_local_w_offsets(
         fake_session,
         offsets_col=identifiers.ColumnId("offsets"),
     )
-    ensure_equivalence(local_node, REFERENCE_ENGINE, engine)
+    assert_equivalence_execution(local_node, REFERENCE_ENGINE, engine)
 
 
 def test_engines_read_local_w_col_subset(
@@ -84,7 +70,7 @@ def test_engines_read_local_w_col_subset(
     local_node = nodes.ReadLocalNode(
         managed_data_source, scan_list, fake_session, offsets_col=None
     )
-    ensure_equivalence(local_node, REFERENCE_ENGINE, engine)
+    assert_equivalence_execution(local_node, REFERENCE_ENGINE, engine)
 
 
 def test_engines_read_local_w_zero_row_source(
@@ -99,7 +85,7 @@ def test_engines_read_local_w_zero_row_source(
     local_node = nodes.ReadLocalNode(
         zero_row_source, scan_list, fake_session, offsets_col=None
     )
-    ensure_equivalence(local_node, REFERENCE_ENGINE, engine)
+    assert_equivalence_execution(local_node, REFERENCE_ENGINE, engine)
 
 
 def test_engines_read_local_w_nested_source(
@@ -114,7 +100,7 @@ def test_engines_read_local_w_nested_source(
     local_node = nodes.ReadLocalNode(
         nested_data_source, scan_list, fake_session, offsets_col=None
     )
-    ensure_equivalence(local_node, REFERENCE_ENGINE, engine)
+    assert_equivalence_execution(local_node, REFERENCE_ENGINE, engine)
 
 
 def test_engines_read_local_w_repeated_source(
@@ -129,4 +115,4 @@ def test_engines_read_local_w_repeated_source(
     local_node = nodes.ReadLocalNode(
         repeated_data_source, scan_list, fake_session, offsets_col=None
     )
-    ensure_equivalence(local_node, REFERENCE_ENGINE, engine)
+    assert_equivalence_execution(local_node, REFERENCE_ENGINE, engine)

tests/system/small/engines/test_selection.py

@@ -0,0 +1,60 @@
+# 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 pytest
+
+from bigframes.core import array_value, expression, identifiers, nodes
+from bigframes.session import polars_executor
+from tests.system.small.engines.engine_utils import assert_equivalence_execution
+
+pytest.importorskip("polars")
+
+# Polars used as reference as its fast and local. Generally though, prefer gbq engine where they disagree.
+REFERENCE_ENGINE = polars_executor.PolarsExecutor()
+
+
+def test_engines_select_identity(
+    scalars_array_value: array_value.ArrayValue,
+    engine,
+):
+    selection = tuple(
+        nodes.AliasedRef(expression.deref(col), identifiers.ColumnId(col))
+        for col in scalars_array_value.column_ids
+    )
+    node = nodes.SelectionNode(scalars_array_value.node, selection)
+    assert_equivalence_execution(node, REFERENCE_ENGINE, engine)
+
+
+def test_engines_select_rename(
+    scalars_array_value: array_value.ArrayValue,
+    engine,
+):
+    selection = tuple(
+        nodes.AliasedRef(expression.deref(col), identifiers.ColumnId(f"renamed_{col}"))
+        for col in scalars_array_value.column_ids
+    )
+    node = nodes.SelectionNode(scalars_array_value.node, selection)
+    assert_equivalence_execution(node, REFERENCE_ENGINE, engine)
+
+
+def test_engines_select_reorder_rename_drop(
+    scalars_array_value: array_value.ArrayValue,
+    engine,
+):
+    selection = tuple(
+        nodes.AliasedRef(expression.deref(col), identifiers.ColumnId(f"renamed_{col}"))
+        for col in scalars_array_value.column_ids[::-2]
+    )
+    node = nodes.SelectionNode(scalars_array_value.node, selection)
+    assert_equivalence_execution(node, REFERENCE_ENGINE, engine)