Refactoring while review

aiogram/fsm/storage/base.py

@@ -72,11 +72,11 @@ class DefaultKeyBuilder(KeyBuilder):
         if self.with_destiny:
             parts.append(key.destiny)
         elif key.destiny != DEFAULT_DESTINY:
-            raise ValueError(
+            error_message = (
                 "Default key builder is not configured to use key destiny other than the default."
-                "\n\n"
-                "Probably, you should set `with_destiny=True` in for DefaultKeyBuilder."
+                "\n\nProbably, you should set `with_destiny=True` in for DefaultKeyBuilder."
             )
+            raise ValueError(error_message)
         parts.append(part)
         return self.separator.join(parts)
 

aiogram/fsm/storage/mongo.py

@@ -44,7 +44,7 @@ class MongoStorage(BaseStorage):
 
     @classmethod
     def from_url(
-        cls, url: str, connection_kwargs: Dict[str, Any] = {}, **kwargs: Any
+        cls, url: str, connection_kwargs: Optional[Dict[str, Any]] = None, **kwargs: Any
     ) -> "MongoStorage":
         """
         Create an instance of :class:`MongoStorage` with specifying the connection string
@@ -54,6 +54,8 @@ class MongoStorage(BaseStorage):
         :param kwargs: arguments to be passed to :class:`MongoStorage`
         :return: an instance of :class:`MongoStorage`
         """
+        if connection_kwargs is None:
+            connection_kwargs = {}
         client = AsyncIOMotorClient(url, **connection_kwargs)
         return cls(client=client, **kwargs)