fix failure

Author: johnzhou721

qasync/__init__.py

@@ -824,7 +824,10 @@ def _use_qeventloop(loop_factory):
         loop = QEventLoop(app)
     else:
         loop = loop_factory(app)
-    old_loop = asyncio.get_event_loop()
+    try:
+        old_loop = asyncio.get_event_loop()
+    except RuntimeError:  # No current event loop
+        old_loop = None
     asyncio.set_event_loop(loop)
     try:
         yield loop

tests/test_run.py

@@ -1,14 +1,17 @@
 import qasync
 import asyncio
+from qasync import QApplication
 
 def test_run_with_contextmanager(application):
     async def coro():
         event_loop = asyncio.get_event_loop()
         assert type(event_loop).__name__ == "QSelectorEventLoop"
         await asyncio.sleep(0)
 
-    _ = application
     qasync.run(coro())
 
-    event_loop = asyncio.get_event_loop()
+    try:
+        event_loop = asyncio.get_event_loop()
+    except:
+        event_loop = None
     assert type(event_loop).__name__ != "QSelectorEventLoop"