feat/ping-endpoint (#1001)

* api: add WebSocket /ping endpoint and update session guard to support WebSocket subprotocol auth; add tests (test_api_ping.py)

* Initial websocket support using ping

* Initial websocket support using ping

* Initial websocket support using ping

* Combine imports

tests/test_api_ping.py

@@ -0,0 +1,32 @@
+from typing import Iterator
+
+import pytest
+from starlette.testclient import TestClient
+
+from facefusion import metadata, session_manager
+from facefusion.apis.core import create_api
+
+
+@pytest.fixture(scope = 'module')
+def test_client() -> Iterator[TestClient]:
+	with TestClient(create_api()) as test_client:
+		yield test_client
+
+
+@pytest.fixture(scope = 'function', autouse = True)
+def before_each() -> None:
+	session_manager.SESSIONS.clear()
+
+
+def test_ping(test_client : TestClient) -> None:
+	create_session_response = test_client.post('/session', json =
+	{
+		'client_version': metadata.get('version')
+	})
+	create_session_body = create_session_response.json()
+
+	with test_client.websocket_connect('/ping', subprotocols =
+	[
+		'access_token.' + create_session_body.get('access_token')
+	]) as websocket:
+		assert websocket