Preprocess async fixtures for each event loop

Caching of fixture preprocessing is now also keyed by event loop id,
sync fixtures can be processed if they are wrapping a async fixture,
each async fixture has a mapping from root scope names to fixture id
that is now used to dynamically get the event loop fixture.

This fixes pytest-dev#862.

Author: cstruct

pytest_asyncio/plugin.py

@@ -238,8 +238,8 @@ def _preprocess_async_fixtures(
     for fixtures in fixturemanager._arg2fixturedefs.values():
         for fixturedef in fixtures:
             func = fixturedef.func
-            if fixturedef in processed_fixturedefs or not _is_coroutine_or_asyncgen(
-                func
+            if not _is_coroutine_or_asyncgen(func) and not getattr(
+                func, "_async_fixture", False
             ):
                 continue
             if not _is_asyncio_fixture_function(func) and asyncio_mode == Mode.STRICT:
@@ -252,14 +252,21 @@ def _preprocess_async_fixtures(
                 or fixturedef.scope
             )
             if scope == "function":
+                event_loop_fixture_name = "function"
                 event_loop_fixture_id: Optional[str] = "event_loop"
             else:
-                event_loop_node = _retrieve_scope_root(collector, scope)
+                try:
+                    event_loop_node = _retrieve_scope_root(collector, scope)
+                except Exception:
+                    continue
+                event_loop_fixture_name = event_loop_node.name
                 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 (fixturedef, event_loop_fixture_id) in processed_fixturedefs:
+                continue
             _make_asyncio_fixture_function(func, scope)
             function_signature = inspect.signature(func)
             if "event_loop" in function_signature.parameters:
@@ -272,42 +279,33 @@ def _preprocess_async_fixtures(
                     )
                 )
             assert event_loop_fixture_id
-            _inject_fixture_argnames(
-                fixturedef,
-                event_loop_fixture_id,
-            )
+            if "request" not in fixturedef.argnames:
+                fixturedef.argnames += ("request",)
             _synchronize_async_fixture(
                 fixturedef,
+                event_loop_fixture_name,
                 event_loop_fixture_id,
             )
             assert _is_asyncio_fixture_function(fixturedef.func)
-            processed_fixturedefs.add(fixturedef)
-
-
-def _inject_fixture_argnames(
-    fixturedef: FixtureDef, event_loop_fixture_id: str
-) -> None:
-    """
-    Ensures that `request` and `event_loop` are arguments of the specified fixture.
-    """
-    to_add = []
-    for name in ("request", event_loop_fixture_id):
-        if name not in fixturedef.argnames:
-            to_add.append(name)
-    if to_add:
-        fixturedef.argnames += tuple(to_add)
+            processed_fixturedefs.add((fixturedef, event_loop_fixture_id))
 
 
 def _synchronize_async_fixture(
-    fixturedef: FixtureDef, event_loop_fixture_id: str
+    fixturedef: FixtureDef, event_loop_fixture_name: str, event_loop_fixture_id: str
 ) -> None:
     """
     Wraps the fixture function of an async fixture in a synchronous function.
     """
-    if inspect.isasyncgenfunction(fixturedef.func):
-        _wrap_asyncgen_fixture(fixturedef, event_loop_fixture_id)
-    elif inspect.iscoroutinefunction(fixturedef.func):
-        _wrap_async_fixture(fixturedef, event_loop_fixture_id)
+    if inspect.isasyncgenfunction(fixturedef.func) or getattr(
+        fixturedef.func, "_async_fixture", False
+    ):
+        _wrap_asyncgen_fixture(
+            fixturedef, event_loop_fixture_name, event_loop_fixture_id
+        )
+    elif inspect.iscoroutinefunction(fixturedef.func) or getattr(
+        fixturedef.func, "_async_fixture", False
+    ):
+        _wrap_async_fixture(fixturedef, event_loop_fixture_name, event_loop_fixture_id)
 
 
 def _add_kwargs(
@@ -345,14 +343,27 @@ def _perhaps_rebind_fixture_func(
     return func
 
 
-def _wrap_asyncgen_fixture(fixturedef: FixtureDef, event_loop_fixture_id: str) -> None:
+def _wrap_asyncgen_fixture(
+    fixturedef: FixtureDef, event_loop_fixture_name: str, event_loop_fixture_id: str
+) -> None:
     fixture = fixturedef.func
 
+    event_loop_id_mapping = getattr(fixture, "_event_loop_id_mapping", {})
+    event_loop_id_mapping[event_loop_fixture_name] = event_loop_fixture_id
+    event_loop_id_mapping["function"] = event_loop_fixture_id
+
+    if getattr(fixture, "_async_fixture", False):
+        return fixture
+
     @functools.wraps(fixture)
     def _asyncgen_fixture_wrapper(request: FixtureRequest, **kwargs: Any):
         unittest = fixturedef.unittest if hasattr(fixturedef, "unittest") else False
         func = _perhaps_rebind_fixture_func(fixture, request.instance, unittest)
-        event_loop = kwargs.pop(event_loop_fixture_id)
+        event_loop_fixture_id = event_loop_id_mapping.get(
+            request.node.name, event_loop_id_mapping["function"]
+        )
+        event_loop = request.getfixturevalue(event_loop_fixture_id)
+        kwargs.pop(event_loop_fixture_id, None)
         gen_obj = func(
             **_add_kwargs(func, kwargs, event_loop_fixture_id, event_loop, request)
         )
@@ -380,17 +391,33 @@ async def async_finalizer() -> None:
         request.addfinalizer(finalizer)
         return result
 
+    setattr(_asyncgen_fixture_wrapper, "_event_loop_id_mapping", event_loop_id_mapping)
+    setattr(_asyncgen_fixture_wrapper, "_async_fixture", True)
+
     fixturedef.func = _asyncgen_fixture_wrapper
 
 
-def _wrap_async_fixture(fixturedef: FixtureDef, event_loop_fixture_id: str) -> None:
+def _wrap_async_fixture(
+    fixturedef: FixtureDef, event_loop_fixture_name: str, event_loop_fixture_id: str
+) -> None:
     fixture = fixturedef.func
 
+    event_loop_id_mapping = getattr(fixture, "_event_loop_id_mapping", {})
+    event_loop_id_mapping[event_loop_fixture_name] = event_loop_fixture_id
+    event_loop_id_mapping["function"] = event_loop_fixture_id
+
+    if getattr(fixture, "_async_fixture", False):
+        return fixture
+
     @functools.wraps(fixture)
     def _async_fixture_wrapper(request: FixtureRequest, **kwargs: Any):
         unittest = False if pytest.version_tuple >= (8, 2) else fixturedef.unittest
         func = _perhaps_rebind_fixture_func(fixture, request.instance, unittest)
-        event_loop = kwargs.pop(event_loop_fixture_id)
+        event_loop_fixture_id = event_loop_id_mapping.get(
+            request.node.name, event_loop_id_mapping["function"]
+        )
+        event_loop = request.getfixturevalue(event_loop_fixture_id)
+        kwargs.pop(event_loop_fixture_id, None)
 
         async def setup():
             res = await func(
@@ -400,6 +427,9 @@ async def setup():
 
         return event_loop.run_until_complete(setup())
 
+    setattr(_async_fixture_wrapper, "_event_loop_id_mapping", event_loop_id_mapping)
+    setattr(_async_fixture_wrapper, "_async_fixture", True)
+
     fixturedef.func = _async_fixture_wrapper
 
 

tests/async_fixtures/test_shared_module_fixture.py

@@ -0,0 +1,35 @@
+from textwrap import dedent
+
+from pytest import Pytester
+
+
+def test_asyncio_mark_provides_package_scoped_loop_strict_mode(pytester: Pytester):
+    pytester.makepyfile(
+        __init__="",
+        conftest=dedent(
+            """\
+            import pytest_asyncio
+            @pytest_asyncio.fixture(scope="module")
+            async def async_shared_module_fixture():
+                return True
+            """
+        ),
+        test_module_one=dedent(
+            """\
+            import pytest
+            @pytest.mark.asyncio
+            async def test_shared_module_fixture_use_a(async_shared_module_fixture):
+                assert async_shared_module_fixture is True
+            """
+        ),
+        test_module_two=dedent(
+            """\
+            import pytest
+            @pytest.mark.asyncio
+            async def test_shared_module_fixture_use_b(async_shared_module_fixture):
+                assert async_shared_module_fixture is True
+            """
+        ),
+    )
+    result = pytester.runpytest("--asyncio-mode=strict")
+    result.assert_outcomes(passed=2)