diff --git a/tests/unit/test_preview_edit_plan_association.py b/tests/unit/test_preview_edit_plan_association.py
index b0d755a83..21c41e826 100644
--- a/tests/unit/test_preview_edit_plan_association.py
+++ b/tests/unit/test_preview_edit_plan_association.py
@@ -13,8 +13,8 @@ from __future__ import annotations
 import os
 import sys
 from dataclasses import dataclass, field
-from typing import Any, Optional
 from types import SimpleNamespace
+from typing import Any, Optional
 from unittest.mock import MagicMock, patch
 
 os.environ.setdefault("JWT_SECRET_KEY", "unit-test-secret-key-for-testing")
@@ -181,12 +181,8 @@ class TestPreviewEditPlanAutoAssociation:
             "packages.adapters.sqlalchemy_impl.edit_plan_repository.SQLAlchemyEditPlanRepository",
             return_value=fake_plan_repo,
         ):
-            with patch(
-                "app.services.edit_plan_service.EditPlanService"
-            ) as MockPlanSvc:
-                MockPlanSvc.return_value.clone_plan_for_variant.return_value = SimpleNamespace(
-                    id="plan-clone-001"
-                )
+            with patch("app.services.edit_plan_service.EditPlanService") as MockPlanSvc:
+                MockPlanSvc.return_value.clone_plan_for_variant.return_value = SimpleNamespace(id="plan-clone-001")
                 resp = client.post(
                     "/api/v1/generation/preview",
                     json=_make_request_body(source_edit_plan_id=""),
@@ -218,9 +214,7 @@ class TestPreviewEditPlanAutoAssociation:
     ):
         """前端已传 source_edit_plan_id 时，不触发自动关联，但仍克隆独立变体 plan"""
         with patch("app.services.edit_plan_service.EditPlanService") as MockPlanSvc:
-            MockPlanSvc.return_value.clone_plan_for_variant.return_value = SimpleNamespace(
-                id="plan-clone-explicit"
-            )
+            MockPlanSvc.return_value.clone_plan_for_variant.return_value = SimpleNamespace(id="plan-clone-explicit")
             resp = client.post(
                 "/api/v1/generation/preview",
                 json=_make_request_body(source_edit_plan_id="plan-explicit-001"),