Create event loop when client constructor needs one

cpgqls_client/client.py

@@ -3,6 +3,15 @@
 import websockets
 
 
+def _get_or_create_event_loop():
+    try:
+        return asyncio.get_event_loop()
+    except RuntimeError:
+        event_loop = asyncio.new_event_loop()
+        asyncio.set_event_loop(event_loop)
+        return event_loop
+
+
 class CPGQLSTransport:
 
     def __init__(self):
@@ -32,7 +41,7 @@ def __init__(self, server_endpoint, event_loop=None, transport=None, auth_creden
         if not isinstance(server_endpoint, str):
             raise ValueError("server_endpoint parameter has to be a string")
 
-        self._loop = asyncio.get_event_loop() if not event_loop else event_loop
+        self._loop = _get_or_create_event_loop() if event_loop is None else event_loop
         self._transport = CPGQLSTransport() if not transport else transport
         self._endpoint = server_endpoint.rstrip("/")
         self._auth_creds = auth_credentials

tests/test_client.py

@@ -92,6 +92,21 @@ def test_basic_execution():
     assert result == post_response_mock.json()
 
 
+def test_client_creates_event_loop_when_current_thread_has_none():
+    asyncio.set_event_loop(None)
+    client = None
+
+    try:
+        client = CPGQLSClient("localhost:8080", transport=Mock())
+
+        assert isinstance(client._loop, asyncio.AbstractEventLoop)
+        assert asyncio.get_event_loop() is client._loop
+    finally:
+        if client is not None:
+            client._loop.close()
+        asyncio.set_event_loop(None)
+
+
 def test_get_response_not_200():
     event_loop = asyncio.new_event_loop()
     conn = MockCPGQLTransportConnection("connected", "received")