Add prototype of class-based handlers

tests/test_dispatcher/test_event/test_handler.py

@@ -3,8 +3,11 @@ from typing import Any, Dict, Union
 
 import pytest
 
+from aiogram.api.types import Update
 from aiogram.dispatcher.event.handler import CallableMixin, FilterObject, HandlerObject
+from aiogram.dispatcher.filters import Text
 from aiogram.dispatcher.filters.base import BaseFilter
+from aiogram.dispatcher.handler.base import BaseHandler
 
 
 def callback1(foo: int, bar: int, baz: int):
@@ -174,3 +177,25 @@ class TestHandlerObject:
         )
         result, data = await handler.check(42, foo=True)
         assert not result
+
+    @pytest.mark.asyncio
+    async def test_class_based_handler(self):
+        class MyFilter(BaseFilter):
+            async def __call__(self, event):
+                return True
+
+        class MyHandler(BaseHandler):
+            event: Update
+            filters = [MyFilter()]
+
+            async def handle(self) -> Any:
+                return self.event.update_id
+
+        handler = HandlerObject(MyHandler, filters=[FilterObject(lambda event: True)])
+
+        assert handler.awaitable
+        assert handler.callback == MyHandler
+        assert len(handler.filters) == 2
+        assert handler.filters[1].callback == MyFilter()
+        result = await handler.call(Update(update_id=42))
+        assert result == 42

tests/test_dispatcher/test_handler/test_base.py

@@ -0,0 +1,47 @@
+import asyncio
+from typing import Any
+
+import pytest
+
+from aiogram import Bot
+from aiogram.api.types import Update
+from aiogram.dispatcher.handler.base import BaseHandler
+
+
+class MyHandler(BaseHandler):
+    async def handle(self) -> Any:
+        await asyncio.sleep(0.1)
+        return 42
+
+
+class TestBaseClassBasedHandler:
+    @pytest.mark.asyncio
+    async def test_base_handler(self):
+        event = Update(update_id=42)
+        handler = MyHandler(event=event, key=42)
+
+        assert handler.event == event
+        assert handler.data["key"] == 42
+        assert hasattr(handler, "bot")
+        assert not hasattr(handler, "filters")
+        assert await handler == 42
+
+    @pytest.mark.asyncio
+    async def test_bot_mixin_from_context(self):
+        event = Update(update_id=42)
+        handler = MyHandler(event=event, key=42)
+        bot = Bot("42:TEST")
+
+        assert handler.bot is None
+
+        Bot.set_current(bot)
+        assert handler.bot == bot
+
+    @pytest.mark.asyncio
+    async def test_bot_mixin_from_data(self):
+        event = Update(update_id=42)
+        bot = Bot("42:TEST")
+        handler = MyHandler(event=event, key=42, bot=bot)
+
+        assert "bot" in handler.data
+        assert handler.bot == bot

tests/test_dispatcher/test_handler/test_message.py

@@ -0,0 +1,28 @@
+import datetime
+from typing import Any
+
+import pytest
+
+from aiogram.api.types import Chat, Message, User
+from aiogram.dispatcher.handler.message import MessageHandler
+
+
+class MyHandler(MessageHandler):
+    async def handle(self) -> Any:
+        return self.event.text
+
+
+class TestClassBasedMessageHandler:
+    @pytest.mark.asyncio
+    async def test_message_handler(self):
+        event = Message(
+            message_id=42,
+            date=datetime.datetime.now(),
+            text="test",
+            chat=Chat(id=42, type="private"),
+            from_user=User(id=42, is_bot=False, first_name="Test"),
+        )
+        handler = MyHandler(event=event)
+
+        assert handler.from_user == event.from_user
+        assert handler.chat == event.chat