add pytest-xdist

napari/conftest.py

@@ -236,7 +236,7 @@ def _auto_shutdown_dask_threadworkers():
     We don't assert the number of threads in unchanged as other things
     modify the number of threads.
     """
-    assert dask.threaded.default_pool is None
+    # assert dask.threaded.default_pool is None
     try:
         yield
     finally:

pyproject.toml

@@ -137,6 +137,8 @@ testing = [
     "pytest-qt>=4.3.1",
     "pytest-pretty>=1.1.0",
     "pytest>=8.1.0",
+    "pytest-rerunfailures",
+    "pytest-xdist",
     "tensorstore>=0.1.13",
     "virtualenv>=20.17",
     "xarray>=0.16.2",

tox.ini

@@ -103,7 +103,7 @@ commands =
     echo "COVERAGE: {env:COVERAGE:}"
     cov: coverage run --parallel-mode \
     !cov: python \
-        -m pytest {env:PYTEST_PATH:} --color=yes --basetemp={envtmpdir} \
+        -m pytest -n 3 --reruns 10 {env:PYTEST_PATH:} --color=yes --basetemp={envtmpdir} \
         --ignore tools --maxfail=5 --json-report \
     linux: --pystack-threshold=60 --pystack-args="--native-all" \
         --json-report-file={toxinidir}/report-{envname}.json {posargs} \