Fixed transport property of the simple clients to be a string as documented (Fixes #1499)

src/socketio/async_simple_client.py

@@ -105,7 +105,7 @@ class AsyncSimpleClient:
         The transport is returned as a string and can be one of ``polling``
         and ``websocket``.
         """
-        return self.client.transport if self.client else ''
+        return self.client.transport() if self.client else ''
 
     async def emit(self, event, data=None):
         """Emit an event to the server.

src/socketio/simple_client.py

@@ -103,7 +103,7 @@ class SimpleClient:
         The transport is returned as a string and can be one of ``polling``
         and ``websocket``.
         """
-        return self.client.transport if self.client else ''
+        return self.client.transport() if self.client else ''
 
     def emit(self, event, data=None):
         """Emit an event to the server.

tests/async/test_simple_client.py

@@ -72,7 +72,7 @@ class TestAsyncAsyncSimpleClient:
 
     async def test_properties(self):
         client = AsyncSimpleClient()
-        client.client = mock.MagicMock(transport='websocket')
+        client.client = mock.MagicMock(transport=lambda: 'websocket')
         client.client.get_sid.return_value = 'sid'
         client.connected_event.set()
         client.connected = True

tests/common/test_simple_client.py

@@ -64,7 +64,7 @@ class TestSimpleClient:
 
     def test_properties(self):
         client = SimpleClient()
-        client.client = mock.MagicMock(transport='websocket')
+        client.client = mock.MagicMock(transport=lambda: 'websocket')
         client.client.get_sid.return_value = 'sid'
         client.connected_event.set()
         client.connected = True