Extend MagicFilter with aiogram-specific operation

aiogram/utils/magic_filter.py

@@ -0,0 +1,20 @@
+from typing import Any
+
+from magic_filter import MagicFilter as _MagicFilter
+from magic_filter.operations import BaseOperation
+
+
+class AsFilterResultOperation(BaseOperation):
+    __slots__ = ("name",)
+
+    def __init__(self, name: str) -> None:
+        self.name = name
+
+    def resolve(self, value: Any, initial_value: Any) -> Any:
+        if value:
+            return {self.name: value}
+
+
+class MagicFilter(_MagicFilter):
+    def as_(self, name: str) -> "MagicFilter":
+        return self._extend(AsFilterResultOperation(name=name))