Move WebLoop patch to conftest.py

Author: agriyakhetarpal

src/zarr/core/sync.py

@@ -4,7 +4,6 @@
 import atexit
 import logging
 import os
-import sys
 import threading
 from concurrent.futures import ThreadPoolExecutor, wait
 from typing import TYPE_CHECKING, Any, TypeVar
@@ -38,45 +37,6 @@ class SyncError(Exception):
     pass
 
 
-# TODO: not sure if there is a better place to put this function, so I've kept it here for now.
-def _make_shutdown_asyncgens_noop_for_pyodide() -> None:
-    """
-    Patch Pyodide's WebLoop to fix interoperability with pytest-asyncio.
-
-    WebLoop.shutdown_asyncgens() raises NotImplementedError, which causes
-    pytest-asyncio to issue warnings during test cleanup and potentially
-    cause resource leaks that make tests hang. This is a bit of a
-    hack, but it allows us to run tests that use pytest-asyncio.
-
-    This is necessary because pytest-asyncio tries to clean up async generators
-    when tearing down test event loops, but Pyodide's WebLoop doesn't support
-    this as it integrates with the browser's event loop rather than managing
-    its own lifecycle.
-    """
-    try:
-        if not IS_WASM and "pyodide" not in sys.modules:
-            return
-
-        import pyodide.webloop
-
-        if hasattr(pyodide.webloop.WebLoop, "shutdown_asyncgens"):
-
-            async def no_op_shutdown_asyncgens(self) -> None:  # type: ignore[no-untyped-def]  # noqa: ANN001
-                return
-
-            pyodide.webloop.WebLoop.shutdown_asyncgens = no_op_shutdown_asyncgens
-            logger.debug("Patched WebLoop.shutdown_asyncgens for pytest-asyncio compatibility")
-
-    # If patching fails for any reason, we log it, but we won't want to crash Zarr
-    except Exception as e:
-        msg = f"Could not patch WebLoop for pytest compatibility: {e}"
-        logger.debug(msg)
-
-
-if IS_WASM:
-    _make_shutdown_asyncgens_noop_for_pyodide()
-
-
 def _get_lock() -> threading.Lock:
     """Allocate or return a threading lock.
 

tests/conftest.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import pathlib
+import sys
 from dataclasses import dataclass, field
 from typing import TYPE_CHECKING
 
@@ -106,6 +107,45 @@ def sync_store(request: pytest.FixtureRequest, tmp_path: LEGACY_PATH) -> Store:
     return result
 
 
+@pytest.fixture(autouse=(IS_WASM and "pyodide" in sys.modules), scope="session")
+def patch_pyodide_webloop_for_pytest() -> Generator[None, None, None]:
+    """
+    Patch Pyodide's WebLoop to fix interoperability with pytest-asyncio.
+
+    WebLoop.shutdown_asyncgens() raises NotImplementedError, which causes
+    pytest-asyncio to issue warnings during test cleanup and potentially
+    cause resource leaks that make tests hang. This is a bit of a
+    hack, but it allows us to run tests that use pytest-asyncio.
+
+    This is necessary because pytest-asyncio tries to clean up async generators
+    when tearing down test event loops, but Pyodide's WebLoop doesn't support
+    this as it integrates with the browser's event loop rather than managing
+    its own lifecycle.
+    """
+    import logging
+
+    logger = logging.getLogger(__name__)
+
+    try:
+        import pyodide.webloop
+
+        if hasattr(pyodide.webloop.WebLoop, "shutdown_asyncgens"):
+
+            async def no_op_shutdown_asyncgens(self) -> None:  # type: ignore[no-untyped-def]
+                return
+
+            pyodide.webloop.WebLoop.shutdown_asyncgens = no_op_shutdown_asyncgens
+            logger.debug("Patched WebLoop.shutdown_asyncgens for pytest-asyncio compatibility")
+
+        yield
+
+    # If patching fails for any reason, we log it, but we won't want to crash the tests
+    except Exception as e:
+        msg = f"Could not patch WebLoop for pytest compatibility: {e}"
+        logger.debug(msg)
+        yield
+
+
 @dataclass
 class AsyncGroupRequest:
     zarr_format: ZarrFormat