pin pytest-asyncio for outdated jupyterhub

.github/workflows/test.yaml

@@ -31,10 +31,13 @@ jobs:
       fail-fast: false
       matrix:
         include:
+          # jupyterhub 4 works with pytest-asyncio 0.25
+          # but requires some deprecated features,
+          # so don't let it upgrade further
           - python-version: "3.9"
-            pip-install-spec: "jupyterhub==4.* sqlalchemy==1.*"
+            pip-install-spec: "jupyterhub==4.* sqlalchemy==1.* pytest-asyncio==0.25.*"
           - python-version: "3.11"
-            pip-install-spec: "jupyterhub==4.*"
+            pip-install-spec: "jupyterhub==4.* pytest-asyncio==0.25.*"
             test-variation: podman
           - python-version: "3.12"
             pip-install-spec: "jupyterhub==5.*"

dev-requirements.txt

@@ -1,5 +1,5 @@
 netifaces
 notebook<7
 pytest>=3.6
-pytest-asyncio>=0.24
+pytest-asyncio>=0.25
 pytest-cov

tests/conftest.py

@@ -1,5 +1,6 @@
 """pytest config for dockerspawner tests"""
 
+import inspect
 import json
 import os
 from textwrap import indent
@@ -18,6 +19,10 @@
 from jupyterhub.tests.conftest import user  # noqa: F401
 from jupyterhub.tests.mocking import MockHub
 
+if 'event_loop' in inspect.signature(io_loop).parameters:
+    # older JupyterHub (< 5.x), io_loop requires deprecated event_loop
+    from jupyterhub.tests.conftest import event_loop  # noqa: F401
+
 from dockerspawner import DockerSpawner, SwarmSpawner, SystemUserSpawner
 
 # import base jupyterhub fixtures