Fix more event loop fetching

Primarily due to version changes over time, this all used to work in
older versions, but Python 3.12 started issuing new warnings and errors
unless manual steps are used for event loop handling instead of automatic steps.

Fixes #2

eventkit/util.py

@@ -1,5 +1,7 @@
 import asyncio
 import datetime as dt
+import functools
+
 from typing import AsyncIterator
 
 
@@ -16,9 +18,17 @@ def __repr__(self):
 NO_VALUE = _NoValue()
 
 
+@functools.cache
 def get_event_loop():
-    """Get asyncio event loop, running or not."""
-    return asyncio.get_event_loop_policy().get_event_loop()
+    """Get asyncio event loop or create one if it doesn't exist."""
+    try:
+        # https://docs.python.org/3/library/asyncio-eventloop.html#asyncio.get_running_loop
+        loop = asyncio.get_running_loop()
+    except RuntimeError:
+        loop = asyncio.new_event_loop()
+        asyncio.set_event_loop(loop)
+
+    return loop
 
 
 async def timerange(start=0, end=None, step: float = 1) -> AsyncIterator[dt.datetime]:

tests/create_test.py

@@ -6,11 +6,10 @@
 array1 = list(range(10))
 array2 = list(range(100, 110))
 
-loop = asyncio.get_event_loop_policy().get_event_loop()
-
 
 class CreateTest(unittest.TestCase):
     def test_wait(self):
+        loop = asyncio.get_event_loop_policy().get_event_loop()
         fut = asyncio.Future(loop=loop)
         loop.call_later(0.001, fut.set_result, 42)
         event = Event.wait(fut)

tests/event_test.py

@@ -4,8 +4,10 @@
 import eventkit as ev
 from eventkit import Event
 
-loop = asyncio.get_event_loop_policy().get_event_loop()
-run = loop.run_until_complete
+
+def run(*args, **kwargs):
+    loop = asyncio.get_event_loop_policy().get_event_loop()
+    return loop.run_until_complete(*args, **kwargs)
 
 
 class Object:

tests/transform_test.py

@@ -6,9 +6,6 @@
 
 from eventkit import Event
 
-loop = asyncio.get_event_loop_policy().get_event_loop()
-loop.set_debug(True)
-
 array = list(range(20))