testing: _for_testing_peer_closed_connection doesn't need extra context switch

Author: belm0

trio_websocket/_impl.py

@@ -9,7 +9,7 @@
 import ssl
 import struct
 import urllib.parse
-from typing import List, Optional
+from typing import List
 
 import trio
 import trio.abc
@@ -744,10 +744,9 @@ def __init__(self, stream, ws_connection, *, host=None, path=None,
         # Set once a WebSocket closed handshake takes place, i.e after a close
         # frame has been sent and a close frame has been received.
         self._close_handshake = trio.Event()
-        # When not None, set immediately upon receiving CloseConnection from peer,
-        # followed by sleep(0) for a context switch.  Used to test close race
-        # conditions between client and server.
-        self._for_testing_peer_closed_connection: Optional[trio.Event] = None
+        # Set upon receiving CloseConnection from peer.
+        # Used to test close race conditions between client and server.
+        self._for_testing_peer_closed_connection = trio.Event()
 
     @property
     def closed(self):
@@ -1105,9 +1104,7 @@ async def _handle_close_connection_event(self, event):
             # Set _close_reason in advance, so that send_message() will raise
             # ConnectionClosed during the close handshake.
             self._close_reason = CloseReason(event.code, event.reason or None)
-            if self._for_testing_peer_closed_connection:
-                self._for_testing_peer_closed_connection.set()
-                await trio.sleep(0)
+            self._for_testing_peer_closed_connection.set()
             await self._send(event.response())
         await self._close_web_socket(event.code, event.reason or None)
         self._close_handshake.set()