feat: reduce duplicate code in aio MessageBus (#272)

src/dbus_fast/aio/message_bus.py

@@ -4,6 +4,7 @@
 import socket
 from collections import deque
 from copy import copy
+from functools import partial
 from typing import Any, Callable, List, Optional, Set, Tuple
 
 from .. import introspection as intr
@@ -288,13 +289,7 @@ async def introspect(
         """
         future = self._loop.create_future()
 
-        def reply_handler(reply: Any, err: Exception) -> None:
-            if err:
-                _future_set_exception(future, err)
-            else:
-                _future_set_result(future, reply)
-
-        super().introspect(bus_name, path, reply_handler)
+        super().introspect(bus_name, path, partial(self._reply_handler, future))
 
         timer_handle = self._loop.call_later(
             timeout, _future_set_exception, future, asyncio.TimeoutError
@@ -326,13 +321,7 @@ async def request_name(
         """
         future = self._loop.create_future()
 
-        def reply_handler(reply, err):
-            if err:
-                _future_set_exception(future, err)
-            else:
-                _future_set_result(future, reply)
-
-        super().request_name(name, flags, reply_handler)
+        super().request_name(name, flags, partial(self._reply_handler, future))
 
         return await future
 
@@ -354,13 +343,7 @@ async def release_name(self, name: str) -> ReleaseNameReply:
         """
         future = self._loop.create_future()
 
-        def reply_handler(reply, err):
-            if err:
-                _future_set_exception(future, err)
-            else:
-                _future_set_result(future, reply)
-
-        super().release_name(name, reply_handler)
+        super().release_name(name, partial(self._reply_handler, future))
 
         return await future
 
@@ -387,14 +370,7 @@ async def call(self, msg: Message) -> Optional[Message]:
 
         future = self._loop.create_future()
 
-        def reply_handler(reply, err):
-            if not future.done():
-                if err:
-                    _future_set_exception(future, err)
-                else:
-                    _future_set_result(future, reply)
-
-        self._call(msg, reply_handler)
+        self._call(msg, partial(self._reply_handler, future))
 
         await future
 
@@ -546,3 +522,12 @@ def _finalize(self, err: Optional[Exception] = None) -> None:
             _future_set_exception(self._disconnect_future, err)
         else:
             _future_set_result(self._disconnect_future, None)
+
+    def _reply_handler(
+        self, future: asyncio.Future, reply: Optional[Any], err: Optional[Exception]
+    ) -> None:
+        """The reply handler for method calls."""
+        if err:
+            _future_set_exception(future, err)
+        else:
+            _future_set_result(future, reply)