Run tests in CI using pytest-xdist, refs #1289

.github/workflows/test.yml

@@ -26,4 +26,5 @@ jobs:
         pip install -e '.[test]'
     - name: Run tests
       run: |
-        pytest
+        pytest -n auto -m "not serial"
+        pytest -m "serial"

pytest.ini

@@ -6,3 +6,5 @@ filterwarnings=
     ignore:Using or importing the ABCs::bs4.element
     # Python 3.7 PendingDeprecationWarning: Task.current_task()
     ignore:.*current_task.*:PendingDeprecationWarning
+markers =
+    serial: tests to avoid using with pytest-xdist

setup.py

@@ -70,6 +70,7 @@ def get_version():
         "docs": ["sphinx_rtd_theme", "sphinx-autobuild"],
         "test": [
             "pytest>=5.2.2,<6.3.0",
+            "pytest-xdist>=2.2.1,<2.3",
             "pytest-asyncio>=0.10,<0.15",
             "beautifulsoup4>=4.8.1,<4.10.0",
             "black==20.8b1",

tests/test_cli_serve_server.py

@@ -1,6 +1,8 @@
 import httpx
+import pytest
 
 
+@pytest.mark.serial
 def test_serve_localhost_http(ds_localhost_http_server):
     response = httpx.get("http://localhost:8041/_memory.json")
     assert {
@@ -10,6 +12,7 @@ def test_serve_localhost_http(ds_localhost_http_server):
     }.items() <= response.json().items()
 
 
+@pytest.mark.serial
 def test_serve_localhost_https(ds_localhost_https_server):
     _, client_cert = ds_localhost_https_server
     response = httpx.get("https://localhost:8042/_memory.json", verify=client_cert)