Preserve exception context in Client.connect (#1450)

Author: tvanbaak

src/socketio/async_client.py

@@ -158,7 +158,7 @@ async def connect(self, url, headers={}, auth=None, transports=None,
                 await self._handle_reconnect()
                 if self.eio.state == 'connected':
                     return
-            raise exceptions.ConnectionError(exc.args[0]) from None
+            raise exceptions.ConnectionError(exc.args[0]) from exc
 
         if wait:
             try:

src/socketio/client.py

@@ -156,7 +156,7 @@ def connect(self, url, headers={}, auth=None, transports=None,
                 self._handle_reconnect()
                 if self.eio.state == 'connected':
                     return
-            raise exceptions.ConnectionError(exc.args[0]) from None
+            raise exceptions.ConnectionError(exc.args[0]) from exc
 
         if wait:
             while self._connect_event.wait(timeout=wait_timeout):