Workaround for Python 3.7 on Windows

tests/conftest.py

@@ -18,10 +18,11 @@
 ############################################################################
 import asyncio
 import pathlib
+import sys
 
 import pytest
 
-from pygls import uris, IS_PYODIDE
+from pygls import uris, IS_PYODIDE, IS_WIN
 from pygls.feature_manager import FeatureManager
 from pygls.workspace import Document, Workspace
 
@@ -80,7 +81,13 @@ def workspace_dir():
 def event_loop():
     """Redefine `pytest-asyncio's default event_loop fixture to match the scope
     of our client fixture."""
-    policy = asyncio.get_event_loop_policy()
+
+    # Only required for Python 3.7 on Windows.
+    if sys.version_info.minor == 7 and IS_WIN:
+        policy = asyncio.WindowsProactorEventLoopPolicy()
+    else:
+        policy = asyncio.get_event_loop_policy()
+
     loop = policy.new_event_loop()
     yield loop