From 66cc90bbad4084366605999332003b019ddeae42 Mon Sep 17 00:00:00 2001
From: Bing Li <63471091+sfc-gh-bli@users.noreply.github.com>
Date: Fri, 17 Jan 2025 10:10:21 -0800
Subject: [PATCH] SNOW-1882588 Add Test for PR 2136 (#2138)

---
 test/unit/test_cursor.py | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/test/unit/test_cursor.py b/test/unit/test_cursor.py
index f72651d44..7b04c43e5 100644
--- a/test/unit/test_cursor.py
+++ b/test/unit/test_cursor.py
@@ -62,6 +62,21 @@ def test_cursor_attribute():
     assert cursor.lastrowid is None
 
 
+def test_query_can_be_empty_with_dataframe_ast():
+    def mock_is_closed(*args, **kwargs):
+        return False
+
+    fake_conn = FakeConnection()
+    fake_conn.is_closed = mock_is_closed
+    cursor = SnowflakeCursor(fake_conn)
+    # when `dataframe_ast` is not presented, the execute function return None
+    assert cursor.execute("") is None
+    # when `dataframe_ast` is presented, it should not return `None`
+    # but raise `AttributeError` since `_paramstyle` is not set in FakeConnection.
+    with pytest.raises(AttributeError):
+        cursor.execute("", _dataframe_ast="ABCD")
+
+
 @patch("snowflake.connector.cursor.SnowflakeCursor._SnowflakeCursor__cancel_query")
 def test_cursor_execute_timeout(mockCancelQuery):
     def mock_cmd_query(*args, **kwargs):