Skip ID for single factories

Author: tjkuson

pytest_asyncio/plugin.py

@@ -766,10 +766,12 @@ def pytest_generate_tests(metafunc: pytest.Metafunc) -> None:
     metafunc.fixturenames.append(_asyncio_loop_factory.__name__)
     default_loop_scope = _get_default_test_loop_scope(metafunc.config)
     loop_scope = marker_loop_scope or default_loop_scope
+    # pytest.HIDDEN_PARAM was added in pytest 8.4
+    hide_id = len(effective_factories) == 1 and hasattr(pytest, "HIDDEN_PARAM")
     metafunc.parametrize(
         _asyncio_loop_factory.__name__,
         effective_factories.values(),
-        ids=effective_factories.keys(),
+        ids=(pytest.HIDDEN_PARAM,) if hide_id else effective_factories.keys(),
         indirect=True,
         scope=loop_scope,
     )

tests/test_loop_factory_parametrization.py

@@ -6,6 +6,35 @@
 from pytest import Pytester
 
 
+@pytest.mark.skipif(
+    not hasattr(pytest, "HIDDEN_PARAM"),
+    reason="pytest.HIDDEN_PARAM requires pytest 9.0+",
+)
+def test_single_factory_does_not_add_suffix_to_test_name(
+    pytester: Pytester,
+) -> None:
+    pytester.makeini("[pytest]\nasyncio_default_fixture_loop_scope = function")
+    pytester.makeconftest(dedent("""\
+        import asyncio
+
+        def pytest_asyncio_loop_factories(config, item):
+            return {"asyncio": asyncio.new_event_loop}
+        """))
+    pytester.makepyfile(dedent("""\
+        import pytest
+
+        pytest_plugins = "pytest_asyncio"
+
+        @pytest.mark.asyncio
+        async def test_example():
+            assert True
+        """))
+    result = pytester.runpytest("--asyncio-mode=strict", "--collect-only", "-q")
+    result.stdout.fnmatch_lines(
+        ["test_single_factory_does_not_add_suffix_to_test_name.py::test_example"]
+    )
+
+
 def test_named_hook_factories_apply_to_async_tests(pytester: Pytester) -> None:
     pytester.makeini("[pytest]\nasyncio_default_fixture_loop_scope = function")
     pytester.makeconftest(dedent("""\