fix: 优化并发数批量设置接口，引入 c.close() 资源管理并增加对 list_accounts() 返回 None 的拦截保护

backend/test_account_concurrency.py

@@ -98,8 +98,17 @@ def test_set_website_accounts_concurrency_workflow(db_session, monkeypatch):
     bulk_calls = []
     update_calls = []
     list_calls_count = 0
+    closed_count = 0
 
     class MockClient:
+        def __enter__(self):
+            return self
+
+        def __exit__(self, exc_type, exc, tb):
+            nonlocal closed_count
+            closed_count += 1
+            return False
+
         def list_accounts(self):
             nonlocal list_calls_count
             list_calls_count += 1
@@ -146,6 +155,8 @@ def test_set_website_accounts_concurrency_workflow(db_session, monkeypatch):
     assert len(bulk_calls) == 1
     assert bulk_calls[0] == (["1001"], {"concurrency": 200})
     assert len(update_calls) == 0
+    # 验证是否调用了 __exit__ 关闭连接
+    assert closed_count == 1
 
 
 def test_set_website_accounts_concurrency_fallback(db_session, monkeypatch):
@@ -179,8 +190,17 @@ def test_set_website_accounts_concurrency_fallback(db_session, monkeypatch):
 
     bulk_calls = []
     update_calls = []
+    closed_count = 0
 
     class MockClientError:
+        def __enter__(self):
+            return self
+
+        def __exit__(self, exc_type, exc, tb):
+            nonlocal closed_count
+            closed_count += 1
+            return False
+
         def list_accounts(self):
             return [{"id": 1001, "name": "acc-1001", "concurrency": 10}]
 
@@ -210,3 +230,42 @@ def test_set_website_accounts_concurrency_fallback(db_session, monkeypatch):
     assert len(items) == 1
     assert items[0].status == "success"
     assert "逐个更新" in items[0].message
+    assert closed_count == 1
+
+
+def test_set_website_accounts_concurrency_list_accounts_none(db_session, monkeypatch):
+    w = Website(
+        id=1,
+        name="Sub2Api site",
+        site_type="sub2api",
+        base_url="http://sub2api",
+        api_prefix="api/v1",
+        auth_type="bearer",
+        auth_config_json='{"token": "tok1"}'
+    )
+    db_session.add(w)
+    db_session.commit()
+
+    closed_count = 0
+
+    class MockClientNone:
+        def __enter__(self):
+            return self
+
+        def __exit__(self, exc_type, exc, tb):
+            nonlocal closed_count
+            closed_count += 1
+            return False
+
+        def list_accounts(self):
+            return None
+
+    monkeypatch.setattr("app.routers.websites._client", lambda row: MockClientNone())
+
+    req = SetConcurrencyRequest(concurrency=150)
+    res = set_website_accounts_concurrency(wid=w.id, body=req, db=db_session)
+
+    assert res.success is False
+    assert "拉取远端账号列表失败" in res.message
+    assert len(res.items) == 0
+    assert closed_count == 1