From 0ed7c5062e8a4be1b383b640d50b68c181d6c3be Mon Sep 17 00:00:00 2001
From: Thomas Grainger <tagrain@gmail.com>
Date: Thu, 12 Oct 2023 16:06:25 +0100
Subject: [PATCH 1/4] allow setting the Runner(loop_factory=...) from
 IsolatedAsyncioTestCase

---
 Lib/unittest/async_case.py | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/Lib/unittest/async_case.py b/Lib/unittest/async_case.py
index bd2a471156065b..63ff6a5d1f8b61 100644
--- a/Lib/unittest/async_case.py
+++ b/Lib/unittest/async_case.py
@@ -25,12 +25,15 @@ class IsolatedAsyncioTestCase(TestCase):
     # them inside the same task.
 
     # Note: the test case modifies event loop policy if the policy was not instantiated
-    # yet.
+    # yet, unless loop_factory=asyncio.EventLoop is set.
     # asyncio.get_event_loop_policy() creates a default policy on demand but never
     # returns None
     # I believe this is not an issue in user level tests but python itself for testing
     # should reset a policy in every test module
     # by calling asyncio.set_event_loop_policy(None) in tearDownModule()
+    # or set loop_factory=asyncio.EventLoop
+
+    loop_factory = None
 
     def __init__(self, methodName='runTest'):
         super().__init__(methodName)
@@ -118,7 +121,7 @@ def _callMaybeAsync(self, func, /, *args, **kwargs):
 
     def _setupAsyncioRunner(self):
         assert self._asyncioRunner is None, 'asyncio runner is already initialized'
-        runner = asyncio.Runner(debug=True)
+        runner = asyncio.Runner(debug=True, loop_factory=self.loop_factory)
         self._asyncioRunner = runner
 
     def _tearDownAsyncioRunner(self):

From 216dc96866632e6502a0c8832f6c112750065616 Mon Sep 17 00:00:00 2001
From: Thomas Grainger <tagrain@gmail.com>
Date: Thu, 12 Oct 2023 16:10:34 +0100
Subject: [PATCH 2/4] test IsolatedAsyncioTestCase.loop_factory

---
 Lib/test/test_unittest/test_async_case.py | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/Lib/test/test_unittest/test_async_case.py b/Lib/test/test_unittest/test_async_case.py
index a465103b59b6ec..ba1ab838cd4a22 100644
--- a/Lib/test/test_unittest/test_async_case.py
+++ b/Lib/test/test_unittest/test_async_case.py
@@ -484,5 +484,19 @@ async def test_demo1(self):
         result = test.run()
         self.assertTrue(result.wasSuccessful())
 
+    def test_loop_factory(self):
+        asyncio.set_event_loop_policy(None)
+
+        class TestCase1(unittest.IsolatedAsyncioTestCase):
+            loop_factory = asyncio.EventLoop
+
+            async def test_demo1(self):
+                pass
+
+        test = TestCase1('test_demo1')
+        result = test.run()
+        self.assertTrue(result.wasSuccessful())
+        self.assertIsNone(support.maybe_get_event_loop_policy())
+
 if __name__ == "__main__":
     unittest.main()

From a05085f90aa406fc4ff38d1ff92f479f6a4ff6cb Mon Sep 17 00:00:00 2001
From: Thomas Grainger <tagrain@gmail.com>
Date: Thu, 12 Oct 2023 16:14:41 +0100
Subject: [PATCH 3/4] document loop_factory attribute

---
 Doc/library/unittest.rst | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Doc/library/unittest.rst b/Doc/library/unittest.rst
index 21abc583f853a7..c90c554591e748 100644
--- a/Doc/library/unittest.rst
+++ b/Doc/library/unittest.rst
@@ -1571,6 +1571,14 @@ Test cases
 
    .. versionadded:: 3.8
 
+   .. attribute:: loop_factory
+
+      The *loop_factory* passed to :class:`asyncio.Runner`. Override
+      in subclasses with :class:`asyncio.EventLoop` to avoid using the
+      asyncio policy system.
+
+      .. versionadded:: 3.13
+
    .. coroutinemethod:: asyncSetUp()
 
       Method called to prepare the test fixture. This is called after :meth:`setUp`.

From 0fbb8943b73cb332cd1c1a928995f8e61d7a5c7f Mon Sep 17 00:00:00 2001
From: "blurb-it[bot]" <43283697+blurb-it[bot]@users.noreply.github.com>
Date: Thu, 12 Oct 2023 15:16:48 +0000
Subject: [PATCH 4/4] =?UTF-8?q?=F0=9F=93=9C=F0=9F=A4=96=20Added=20by=20blu?=
 =?UTF-8?q?rb=5Fit.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../next/Library/2023-10-12-15-16-44.gh-issue-110774.AdCb5A.rst  | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 Misc/NEWS.d/next/Library/2023-10-12-15-16-44.gh-issue-110774.AdCb5A.rst

diff --git a/Misc/NEWS.d/next/Library/2023-10-12-15-16-44.gh-issue-110774.AdCb5A.rst b/Misc/NEWS.d/next/Library/2023-10-12-15-16-44.gh-issue-110774.AdCb5A.rst
new file mode 100644
index 00000000000000..a5a9fed11864d6
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2023-10-12-15-16-44.gh-issue-110774.AdCb5A.rst
@@ -0,0 +1 @@
+Support setting the :class:`asyncio.Runner` loop_factory kwarg in :class:`unittest.IsolatedAsyncioTestCase`