Preserve middleware data across scene transitions (#1687) (#1766)

* Preserve middleware context across scene goto transitions (#1687)

* Add After.goto coverage for scene middleware context (#1687)

CHANGES/1687.bugfix.rst

@@ -0,0 +1 @@
+Fixed scene transitions to preserve middleware-injected data when moving between scenes via ``SceneWizard.goto``.

aiogram/fsm/scene.py

@@ -259,6 +259,7 @@ class SceneHandlerWrapper:
             )
             raise SceneException(msg) from None
         event_update: Update = kwargs["event_update"]
+        scenes.data = {**scenes.data, **kwargs}
         scene = self.scene(
             wizard=SceneWizard(
                 scene_config=self.scene.__scene_config__,
@@ -712,6 +713,9 @@ class ScenesManager:
         :param kwargs: Additional keyword arguments to pass to the scene's wizard.enter() method.
         :return: None
         """
+        if kwargs:
+            self.data = {**self.data, **kwargs}
+
         if _check_active:
             active_scene = await self._get_active_scene()
             if active_scene is not None:

tests/test_fsm/test_scene.py

@@ -253,6 +253,7 @@ class TestSceneHandlerWrapper:
 
         state_mock = AsyncMock(spec=FSMContext)
         scenes_mock = AsyncMock(spec=ScenesManager)
+        scenes_mock.data = {}
         event_update_mock = Update(
             update_id=42,
             message=Message(
@@ -282,6 +283,7 @@ class TestSceneHandlerWrapper:
 
         state_mock = AsyncMock(spec=FSMContext)
         scenes_mock = AsyncMock(spec=ScenesManager)
+        scenes_mock.data = {}
         event_update_mock = Update(
             update_id=42,
             message=Message(

tests/test_issues/test_1687_scene_goto_loses_middleware_data.py

@@ -0,0 +1,106 @@
+from collections.abc import Awaitable, Callable
+from datetime import datetime
+from typing import Any
+
+from aiogram import BaseMiddleware, Dispatcher
+from aiogram.enums import ChatType
+from aiogram.filters import CommandStart
+from aiogram.fsm.scene import After, Scene, SceneRegistry, on
+from aiogram.types import Chat, Message, TelegramObject, Update, User
+from tests.mocked_bot import MockedBot
+
+
+class TestContextMiddleware(BaseMiddleware):
+    async def __call__(
+        self,
+        handler: Callable[[TelegramObject, dict[str, Any]], Awaitable[Any]],
+        event: TelegramObject,
+        data: dict[str, Any],
+    ) -> Any:
+        data["test_context"] = "context from middleware"
+        return await handler(event, data)
+
+
+class TargetScene(Scene, state="target"):
+    entered_with_context: str | None = None
+
+    @on.message.enter()
+    async def on_enter(self, message: Message, test_context: str) -> None:
+        type(self).entered_with_context = test_context
+
+
+class StartScene(Scene, state="start"):
+    @on.message.enter()
+    async def on_start(self, message: Message) -> None:
+        await self.wizard.goto(TargetScene)
+
+
+class StartSceneWithAfter(Scene, state="start_with_after"):
+    @on.message(after=After.goto(TargetScene))
+    async def goto_target_with_after(self, message: Message) -> None:
+        pass
+
+
+async def test_scene_goto_preserves_message_middleware_data(bot: MockedBot) -> None:
+    dp = Dispatcher()
+    registry = SceneRegistry(dp)
+    registry.add(StartScene, TargetScene)
+    dp.message.register(StartScene.as_handler(), CommandStart())
+    dp.message.middleware(TestContextMiddleware())
+
+    TargetScene.entered_with_context = None
+
+    update = Update(
+        update_id=1,
+        message=Message(
+            message_id=1,
+            date=datetime.now(),
+            chat=Chat(id=42, type=ChatType.PRIVATE),
+            from_user=User(id=42, is_bot=False, first_name="Test"),
+            text="/start",
+        ),
+    )
+
+    await dp.feed_update(bot, update)
+
+    assert TargetScene.entered_with_context == "context from middleware"
+
+
+async def test_scene_after_goto_preserves_message_middleware_data(bot: MockedBot) -> None:
+    dp = Dispatcher()
+    registry = SceneRegistry(dp)
+    registry.add(StartSceneWithAfter, TargetScene)
+    dp.message.register(StartSceneWithAfter.as_handler(), CommandStart())
+    dp.message.middleware(TestContextMiddleware())
+
+    TargetScene.entered_with_context = None
+
+    await dp.feed_update(
+        bot,
+        Update(
+            update_id=1,
+            message=Message(
+                message_id=1,
+                date=datetime.now(),
+                chat=Chat(id=42, type=ChatType.PRIVATE),
+                from_user=User(id=42, is_bot=False, first_name="Test"),
+                text="/start",
+            ),
+        ),
+    )
+
+    await dp.feed_update(
+        bot,
+        Update(
+            update_id=2,
+            message=Message(
+                message_id=2,
+                date=datetime.now(),
+                chat=Chat(id=42, type=ChatType.PRIVATE),
+                from_user=User(id=42, is_bot=False, first_name="Test"),
+                text="go",
+            ),
+        ),
+    )
+
+    assert TargetScene.entered_with_context == "context from middleware"