test: add unit tests for udf experiment options (#1468)

Author: jialuoo

tests/unit/_config/test_experiment_options.py

@@ -46,3 +46,18 @@ def test_blob_set_true_shows_warning():
         options.blob = True
 
     assert options.blob is True
+
+
+def test_udf_default_false():
+    options = experiment_options.ExperimentOptions()
+
+    assert options.udf is False
+
+
+def test_udf_set_true_shows_warning():
+    options = experiment_options.ExperimentOptions()
+
+    with pytest.warns(bfe.PreviewWarning):
+        options.udf = True
+
+    assert options.udf is True