From d6a748262a44334f27008e8c90d2557f46481f5b Mon Sep 17 00:00:00 2001
From: Steven Silvester <steven.silvester@ieee.org>
Date: Tue, 10 Oct 2023 10:33:39 -0500
Subject: [PATCH] Add python 3.12 support (#367)

---
 .github/workflows/test.yml     |  6 ++--
 jupyter_core/utils/__init__.py | 17 +++++++----
 tests/test_async.py            | 34 ---------------------
 tests/test_utils.py            | 56 ++++++++++++++++++++++++++++++++++
 4 files changed, 71 insertions(+), 42 deletions(-)
 delete mode 100644 tests/test_async.py
 create mode 100644 tests/test_utils.py

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index ebb1af99..3f6e6170 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -28,12 +28,14 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest]
-        python-version: ["3.8", "3.11"]
+        python-version: ["3.8", "3.12"]
         include:
           - os: windows-latest
             python-version: "3.9"
           - os: ubuntu-latest
-            python-version: "pypy-3.8"
+            python-version: "3.11"
+          - os: ubuntu-latest
+            python-version: "pypy-3.9"
           - os: macos-latest
             python-version: "3.10"
     steps:
diff --git a/jupyter_core/utils/__init__.py b/jupyter_core/utils/__init__.py
index 0c043d4d..48cd9694 100644
--- a/jupyter_core/utils/__init__.py
+++ b/jupyter_core/utils/__init__.py
@@ -160,12 +160,17 @@ def wrapped(*args: Any, **kwargs: Any) -> Any:
             pass
 
         # Run the loop for this thread.
-        try:
-            loop = asyncio.get_event_loop()
-        except RuntimeError:
-            loop = asyncio.new_event_loop()
-            asyncio.set_event_loop(loop)
-        return loop.run_until_complete(inner)
+        # In Python 3.12, a deprecation warning is raised, which
+        # may later turn into a RuntimeError.  We handle both
+        # cases.
+        with warnings.catch_warnings():
+            warnings.simplefilter("ignore", DeprecationWarning)
+            try:
+                loop = asyncio.get_event_loop()
+            except RuntimeError:
+                loop = asyncio.new_event_loop()
+                asyncio.set_event_loop(loop)
+            return loop.run_until_complete(inner)
 
     wrapped.__doc__ = coro.__doc__
     return wrapped
diff --git a/tests/test_async.py b/tests/test_async.py
deleted file mode 100644
index 924e9a40..00000000
--- a/tests/test_async.py
+++ /dev/null
@@ -1,34 +0,0 @@
-"""Tests for async helper functions"""
-
-# Copyright (c) Jupyter Development Team.
-# Distributed under the terms of the Modified BSD License.
-
-import asyncio
-
-from jupyter_core.utils import ensure_async, run_sync
-
-
-async def afunc():
-    return "afunc"
-
-
-def func():
-    return "func"
-
-
-sync_afunc = run_sync(afunc)
-
-
-def test_ensure_async():
-    async def main():
-        assert await ensure_async(afunc()) == "afunc"
-        assert await ensure_async(func()) == "func"
-
-    asyncio.run(main())
-
-
-def test_run_sync():
-    async def main():
-        assert sync_afunc() == "afunc"
-
-    asyncio.run(main())
diff --git a/tests/test_utils.py b/tests/test_utils.py
new file mode 100644
index 00000000..ad5cbb4f
--- /dev/null
+++ b/tests/test_utils.py
@@ -0,0 +1,56 @@
+"""Tests for utils"""
+
+# Copyright (c) Jupyter Development Team.
+# Distributed under the terms of the Modified BSD License.
+
+import asyncio
+import os
+import tempfile
+
+import pytest
+
+from jupyter_core.utils import deprecation, ensure_async, ensure_dir_exists, run_sync
+
+
+def test_ensure_dir_exists():
+    with tempfile.TemporaryDirectory() as td:
+        ensure_dir_exists(td)
+        ensure_dir_exists(os.path.join(str(td), "foo"), 0o777)
+
+
+def test_deprecation():
+    with pytest.deprecated_call():
+        deprecation("foo")
+
+
+async def afunc():
+    return "afunc"
+
+
+def func():
+    return "func"
+
+
+sync_afunc = run_sync(afunc)
+
+
+def test_run_sync():
+    async def foo():
+        return 1
+
+    foo_sync = run_sync(foo)
+    assert foo_sync() == 1
+    assert foo_sync() == 1
+
+    asyncio.set_event_loop(None)
+    assert foo_sync() == 1
+
+    asyncio.run(foo())
+
+
+def test_ensure_async():
+    async def main():
+        assert await ensure_async(afunc()) == "afunc"
+        assert await ensure_async(func()) == "func"
+
+    asyncio.run(main())