Avoid errors in cleanup when event loop is already closed

check `is_closed()` before calling cleanup methods
and catch errors in cleanup to avoid problems

# Conflicts:
#	docs/reference/changelog.rst

Author: minrk

docs/reference/changelog.rst

@@ -4,9 +4,10 @@ Changelog
 
 0.26.0 (UNRELEASED)
 ===================
-- Adds configuration option that sets default event loop scope for all testss `#793 <https://github.com/pytest-dev/pytest-asyncio/issues/793>`_
+- Adds configuration option that sets default event loop scope for all tests `#793 <https://github.com/pytest-dev/pytest-asyncio/issues/793>`_
 - Improved type annotations for ``pytest_asyncio.fixture`` `#1045 <https://github.com/pytest-dev/pytest-asyncio/pull/1045>`_
 - Added ``typing-extensions`` as additional dependency for Python ``<3.10`` `#1045 <https://github.com/pytest-dev/pytest-asyncio/pull/1045>`_
+- Avoid errors in cleanup when event loop is already closed `#1051 <https://github.com/pytest-dev/pytest-asyncio/issues/1051>`_
 
 
 0.25.2 (2025-01-08)

pytest_asyncio/plugin.py

@@ -1190,10 +1190,14 @@ def _provide_event_loop() -> Iterator[asyncio.AbstractEventLoop]:
     try:
         yield loop
     finally:
-        try:
-            loop.run_until_complete(loop.shutdown_asyncgens())
-        finally:
-            loop.close()
+        # cleanup the event loop if it hasn't been cleaned up already
+        if not loop.is_closed():
+            try:
+                loop.run_until_complete(loop.shutdown_asyncgens())
+            except Exception as e:
+                warnings.warn(f"Error cleaning up asyncio loop: {e}", RuntimeWarning)
+            finally:
+                loop.close()
 
 
 @pytest.fixture(scope="session")

tests/test_event_loop_fixture.py

@@ -80,3 +80,35 @@ async def generator_fn():
     )
     result = pytester.runpytest_subprocess("--asyncio-mode=strict", "-W", "default")
     result.assert_outcomes(passed=1, warnings=0)
+
+
+def test_event_loop_already_closed(
+    pytester: Pytester,
+):
+    pytester.makeini("[pytest]\nasyncio_default_fixture_loop_scope = function")
+    pytester.makepyfile(
+        dedent(
+            """\
+            import asyncio
+            import pytest
+            import pytest_asyncio
+            pytest_plugins = 'pytest_asyncio'
+
+            @pytest_asyncio.fixture
+            async def _event_loop():
+                return asyncio.get_running_loop()
+
+            @pytest.fixture
+            def cleanup_after(_event_loop):
+                yield
+                # fixture has its own cleanup code
+                _event_loop.close()
+
+            @pytest.mark.asyncio
+            async def test_something(cleanup_after):
+                await asyncio.sleep(0.01)
+            """
+        )
+    )
+    result = pytester.runpytest_subprocess("--asyncio-mode=strict", "-W", "default")
+    result.assert_outcomes(passed=1, warnings=0)