Reduce __enter__/__exit__ boilerplate for sync ctx managers

telethon/client/account.py

@@ -2,7 +2,7 @@ import functools
 import inspect
 
 from .users import UserMethods, _NOT_A_REQUEST
-from .. import utils
+from .. import helpers, utils
 from ..tl import functions, TLRequest
 
 
@@ -31,15 +31,6 @@ class _TakeoutClient:
     def success(self, value):
         self.__success = value
 
-    def __enter__(self):
-        if self.__client.loop.is_running():
-            raise RuntimeError(
-                'You must use "async with" if the event loop '
-                'is running (i.e. you are inside an "async def")'
-            )
-
-        return self.__client.loop.run_until_complete(self.__aenter__())
-
     async def __aenter__(self):
         # Enter/Exit behaviour is "overrode", we don't want to call start.
         client = self.__client
@@ -50,9 +41,6 @@ class _TakeoutClient:
                 "takeout for the current session still not been finished yet.")
         return self
 
-    def __exit__(self, *args):
-        return self.__client.loop.run_until_complete(self.__aexit__(*args))
-
     async def __aexit__(self, exc_type, exc_value, traceback):
         if self.__success is None and self.__finalize:
             self.__success = exc_type is None
@@ -64,6 +52,9 @@ class _TakeoutClient:
                 raise ValueError("Failed to finish the takeout.")
             self.session.takeout_id = None
 
+    __enter__ = helpers._sync_enter
+    __exit__ = helpers._sync_exit
+
     async def __call__(self, request, ordered=False):
         takeout_id = self.__client.session.takeout_id
         if takeout_id is None:

telethon/client/auth.py

@@ -536,23 +536,13 @@ class AuthMethods(MessageParseMethods, UserMethods):
 
     # region with blocks
 
-    def __enter__(self):
-        if self._loop.is_running():
-            raise RuntimeError(
-                'You must use "async with" if the event loop '
-                'is running (i.e. you are inside an "async def")'
-            )
-
-        return self.start()
-
     async def __aenter__(self):
         return await self.start()
 
-    def __exit__(self, *args):
-        # No loop.run_until_complete; it's already syncified
-        self.disconnect()
-
     async def __aexit__(self, *args):
         await self.disconnect()
 
+    __enter__ = helpers._sync_enter
+    __exit__ = helpers._sync_exit
+
     # endregion

telethon/client/chats.py

@@ -3,7 +3,7 @@ import itertools
 import string
 
 from .users import UserMethods
-from .. import utils
+from .. import helpers, utils
 from ..requestiter import RequestIter
 from ..tl import types, functions, custom
 
@@ -69,17 +69,8 @@ class _ChatAction:
 
             self._task = None
 
-    def __enter__(self):
+    __enter__ = helpers._sync_enter
-        if self._client.loop.is_running():
+    __exit__ = helpers._sync_exit
-            raise RuntimeError(
-                'You must use "async with" if the event loop '
-                'is running (i.e. you are inside an "async def")'
-            )
-
-        return self._client.loop.run_until_complete(self.__aenter__())
-
-    def __exit__(self, *args):
-        return self._client.loop.run_until_complete(self.__aexit__(*args))
 
     async def _update(self):
         try:

telethon/helpers.py

@@ -102,6 +102,25 @@ async def _cancel(log, **tasks):
         except Exception:
             log.exception('Unhandled exception from %s after cancel', name)
 
+
+def _sync_enter(self):
+    """
+    Helps to cut boilerplate on async context
+    managers that offer synchronous variants.
+    """
+    if self._client.loop.is_running():
+        raise RuntimeError(
+            'You must use "async with" if the event loop '
+            'is running (i.e. you are inside an "async def")'
+        )
+
+    return self._client.loop.run_until_complete(self.__aenter__())
+
+
+def _sync_exit(self, *args):
+    return self._client.loop.run_until_complete(self.__aexit__(*args))
+
+
 # endregion
 
 # region Cryptographic related utils

telethon/tl/custom/conversation.py

@@ -3,7 +3,7 @@ import itertools
 import time
 
 from .chatgetter import ChatGetter
-from ... import utils, errors
+from ... import helpers, utils, errors
 
 
 # Sometimes the edits arrive very fast (within the same second).
@@ -403,15 +403,6 @@ class Conversation(ChatGetter):
             else:
                 fut.cancel()
 
-    def __enter__(self):
-        if self._client.loop.is_running():
-            raise RuntimeError(
-                'You must use "async with" if the event loop '
-                'is running (i.e. you are inside an "async def")'
-            )
-
-        return self._client.loop.run_until_complete(self.__aenter__())
-
     async def __aenter__(self):
         self._input_chat = \
             await self._client.get_input_entity(self._input_chat)
@@ -447,9 +438,6 @@ class Conversation(ChatGetter):
         """Cancels the current conversation and exits the context manager."""
         raise _ConversationCancelled()
 
-    def __exit__(self, *args):
-        return self._client.loop.run_until_complete(self.__aexit__(*args))
-
     async def __aexit__(self, exc_type, exc_val, exc_tb):
         chat_id = utils.get_peer_id(self._chat_peer)
         if self._client._ids_in_conversations[chat_id] == 1:
@@ -461,6 +449,9 @@ class Conversation(ChatGetter):
         self._cancel_all()
         return isinstance(exc_val, _ConversationCancelled)
 
+    __enter__ = helpers._sync_enter
+    __exit__ = helpers._sync_exit
+
 
 class _ConversationCancelled(InterruptedError):
     pass