add tests

python_tests/test_preference_setting.py

@@ -0,0 +1,20 @@
+from __future__ import annotations
+from unittest import TestCase
+
+import optuna
+
+from optuna_dashboard._preference_setting import (
+    register_output_component,
+    _SYSTEM_ATTR_FEEDBACK_ARTIFACT_KEY,
+    _SYSTEM_ATTR_FEEDBACK_COMPONENT_TYPE,
+)
+from optuna_dashboard.preferential._study import PreferentialStudy
+
+
+class FeedbackSettingTestCase(TestCase):
+    def test_widget_to_dict_from_dict(self) -> None:
+        study = PreferentialStudy(optuna.create_study())
+        register_output_component(study, "Artifact", "image_key")
+        system_attrs = study._study.system_attrs
+        assert system_attrs.get(_SYSTEM_ATTR_FEEDBACK_COMPONENT_TYPE, "") == "Artifact"
+        assert system_attrs.get(_SYSTEM_ATTR_FEEDBACK_ARTIFACT_KEY, "") == "image_key"