refactor: Simplified code in _preprocess_async_functions.

The code no longer determines the event_loop_fixture_id. This is now done inside the fixture synchronizers.

Author: seifertm

pytest_asyncio/plugin.py

@@ -251,15 +251,8 @@ def _preprocess_async_fixtures(
                 or default_loop_scope
                 or fixturedef.scope
             )
-            if scope == "function":
-                event_loop_fixture_id: Optional[str] = "event_loop"
-            else:
-                event_loop_node = _retrieve_scope_root(collector, scope)
-                event_loop_fixture_id = event_loop_node.stash.get(
-                    # Type ignored because of non-optimal mypy inference.
-                    _event_loop_fixture_id,  # type: ignore[arg-type]
-                    None,
-                )
+            if scope == "function" and "event_loop" not in fixturedef.argnames:
+                fixturedef.argnames += ("event_loop",)
             _make_asyncio_fixture_function(func, scope)
             function_signature = inspect.signature(func)
             if "event_loop" in function_signature.parameters:
@@ -271,14 +264,8 @@ def _preprocess_async_fixtures(
                         f"instead."
                     )
                 )
-            assert event_loop_fixture_id
             if "request" not in fixturedef.argnames:
                 fixturedef.argnames += ("request",)
-            if (
-                event_loop_fixture_id == "event_loop"
-                and "event_loop" not in fixturedef.argnames
-            ):
-                fixturedef.argnames += ("event_loop",)
             _synchronize_async_fixture(fixturedef)
             assert _is_asyncio_fixture_function(fixturedef.func)
             processed_fixturedefs.add(fixturedef)