fix asyncio deprectation warning

Author: rmorshea

src/idom/backend/flask.py

@@ -80,7 +80,7 @@ async def serve_development_app(
     started: asyncio.Event | None = None,
 ) -> None:
     """Run an application using a development server"""
-    loop = asyncio.get_event_loop()
+    loop = asyncio.get_running_loop()
     stopped = asyncio.Event()
 
     server: Ref[BaseWSGIServer] = Ref()

src/idom/backend/tornado.py

@@ -75,7 +75,7 @@ async def serve_development_app(
 
     try:
         # block forever - tornado has already set up its own background tasks
-        await asyncio.get_event_loop().create_future()
+        await asyncio.get_running_loop().create_future()
     finally:
         # stop accepting new connections
         server.stop()

src/idom/backend/utils.py

@@ -53,9 +53,7 @@ def run(
         f"Running with {app_cls.__module__}.{app_cls.__name__} at http://{host}:{port}"
     )
 
-    asyncio.get_event_loop().run_until_complete(
-        implementation.serve_development_app(app, host, port)
-    )
+    asyncio.run(implementation.serve_development_app(app, host, port))
 
 
 def safe_client_build_dir_path(path: str) -> Path:

src/idom/core/layout.py

@@ -716,7 +716,7 @@ class _ThreadSafeQueue(Generic[_Type]):
     __slots__ = "_loop", "_queue", "_pending"
 
     def __init__(self) -> None:
-        self._loop = asyncio.get_event_loop()
+        self._loop = asyncio.get_running_loop()
         self._queue: asyncio.Queue[_Type] = asyncio.Queue()
         self._pending: Set[_Type] = set()
 

tests/test_backend/test_utils.py

@@ -34,16 +34,15 @@ async def test_run(page: Page, exit_stack: ExitStack):
     port = find_available_port(host)
     url = f"http://{host}:{port}"
 
-    def run_in_thread():
-        asyncio.set_event_loop(loop)
-        sync_run(
+    threading.Thread(
+        target=lambda: sync_run(
             SampleApp,
             host,
             port,
             implementation=flask_implementation,
-        )
-
-    threading.Thread(target=run_in_thread, daemon=True).start()
+        ),
+        daemon=True,
+    ).start()
 
     # give the server a moment to start
     time.sleep(0.5)