This is an automated email from the ASF dual-hosted git repository.
rusackas pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/superset.git
The following commit(s) were added to refs/heads/master by this push:
new a10c3f0b1dd test(result_set): add regression test for empty result set
column metadata (#35962)
a10c3f0b1dd is described below
commit a10c3f0b1dd481670b1b3252c972489034d79429
Author: Phuc Hung Nguyen <[email protected]>
AuthorDate: Tue Jul 28 02:08:59 2026 -0400
test(result_set): add regression test for empty result set column metadata
(#35962)
Co-authored-by: Phuc Hung Nguyen <[email protected]>
Co-authored-by: Claude <[email protected]>
---
tests/unit_tests/result_set_test.py | 50 +++++++++++++++++++++++++++++++++++++
1 file changed, 50 insertions(+)
diff --git a/tests/unit_tests/result_set_test.py
b/tests/unit_tests/result_set_test.py
index 41d7e08f00c..179d092947b 100644
--- a/tests/unit_tests/result_set_test.py
+++ b/tests/unit_tests/result_set_test.py
@@ -571,3 +571,53 @@ def
test_stringify_values_non_serializable_dict_falls_back_to_str() -> None:
# Must not raise — falls back to str()
result = stringify_values(data)
assert result[0] == str({"key": _Unserializable()})
+
+
+def test_empty_result_set_preserves_column_metadata() -> None:
+ """
+ Test that column metadata is preserved when query returns zero rows.
+
+ When a query returns no data but has a valid cursor description, the
+ column names and types from cursor_description should be preserved
+ in the result set. This allows downstream consumers (like the UI)
+ to display column headers even for empty result sets.
+ """
+ data: DbapiResult = []
+ description = [
+ ("id", "int", None, None, None, None, True),
+ ("name", "varchar", None, None, None, None, True),
+ ("created_at", "timestamp", None, None, None, None, True),
+ ]
+
+ result_set = SupersetResultSet(
+ data,
+ description, # type: ignore
+ BaseEngineSpec,
+ )
+
+ # Verify column count
+ assert len(result_set.columns) == 3
+
+ # Verify column names are preserved
+ column_names = [col["column_name"] for col in result_set.columns]
+ assert column_names == ["id", "name", "created_at"]
+
+ assert result_set.columns[0]["type"] == BaseEngineSpec.get_datatype(
+ description[0][1]
+ )
+ assert result_set.columns[1]["type"] == BaseEngineSpec.get_datatype(
+ description[1][1]
+ )
+ assert result_set.columns[2]["type"] == BaseEngineSpec.get_datatype(
+ description[2][1]
+ )
+
+ # Verify the PyArrow table has the correct schema
+ assert result_set.table.num_rows == 0
+ assert len(result_set.table.column_names) == 3
+ assert list(result_set.table.column_names) == ["id", "name", "created_at"]
+
+ # Verify DataFrame conversion works
+ df = result_set.to_pandas_df()
+ assert len(df) == 0
+ assert list(map(str, df.columns)) == ["id", "name", "created_at"]
