Preserve middleware context across scene goto transitions (#1687)

tests/test_issues/test_1687_scene_goto_loses_middleware_data.py

@@ -0,0 +1,60 @@
+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 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)
+
+
+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"