TST: apply returns list (#52912)

Author: srkds

pandas/tests/apply/test_frame_apply.py

@@ -1433,6 +1433,13 @@ def test_apply_on_empty_dataframe():
     tm.assert_series_equal(result, expected)
 
 
+def test_apply_return_list():
+    df = DataFrame({"a": [1, 2], "b": [2, 3]})
+    result = df.apply(lambda x: [x.values])
+    expected = DataFrame({"a": [[1, 2]], "b": [[2, 3]]})
+    tm.assert_frame_equal(result, expected)
+
+
 @pytest.mark.parametrize(
     "test, constant",
     [