No state No Websocket (#1950)

reflex/.templates/web/utils/state.js

@@ -507,7 +507,8 @@ export const useEventLoop = (
     if (!router.isReady) {
       return;
     }
-
+    // only use websockets if state is present
+    if (Object.keys(state).length > 0) {
       // Initialize the websocket connection.
       if (!socket.current) {
         connect(socket, dispatch, ['websocket', 'polling'], setConnectError, client_storage)
@@ -518,6 +519,7 @@ export const useEventLoop = (
           await processEvent(socket.current)
         }
       })()
+    }
   })
   return [state, addEvents, connectError]
 }

reflex/app.py

@@ -175,6 +175,7 @@ class App(Base):
         self.add_cors()
         self.add_default_endpoints()
 
+        if self.state is not DefaultState:
             # Set up the Socket.IO AsyncServer.
             self.sio = AsyncServer(
                 async_mode="asgi",

tests/test_state.py

@@ -14,6 +14,7 @@ import pytest
 from plotly.graph_objects import Figure
 
 import reflex as rx
+from reflex.app import App
 from reflex.base import Base
 from reflex.constants import CompileVars, RouteVar, SocketEvent
 from reflex.event import Event, EventHandler
@@ -1528,23 +1529,24 @@ async def test_state_manager_lock_expire_contend(
 
 
 @pytest.fixture(scope="function")
-def mock_app(monkeypatch, app: rx.App, state_manager: StateManager) -> rx.App:
+def mock_app(monkeypatch, state_manager: StateManager) -> rx.App:
     """Mock app fixture.
 
     Args:
         monkeypatch: Pytest monkeypatch object.
-        app: An app.
         state_manager: A state manager.
 
     Returns:
         The app, after mocking out prerequisites.get_app()
     """
+    app = App(state=TestState)
+
     app_module = Mock()
+
     setattr(app_module, CompileVars.APP, app)
     app.state = TestState
     app.state_manager = state_manager
-    assert app.event_namespace is not None
-    app.event_namespace.emit = AsyncMock()
+    app.event_namespace.emit = AsyncMock()  # type: ignore
     monkeypatch.setattr(prerequisites, "get_app", lambda: app_module)
     return app