Enable parallel and stress testing

src/tests/conftest.py

@@ -5,3 +5,28 @@ import pytest
 @pytest.fixture(autouse=True)
 def mute_logging():
     logging.getLogger().setLevel(logging.WARNING)
+
+
+def pytest_addoption(parser: pytest.Parser) -> None:
+    parser.addoption(
+        "--stress",
+        action="store_true",
+        default=False,
+        help="run stress tests",
+    )
+
+
+def pytest_configure(config: pytest.Config) -> None:
+    config.addinivalue_line("markers", "stress: long running stress tests")
+
+
+def pytest_collection_modifyitems(
+    config: pytest.Config, items: list[pytest.Item]
+) -> None:
+    if config.getoption("--stress"):
+        return
+
+    skip_stress = pytest.mark.skip(reason="need --stress option to run")
+    for item in items:
+        if "stress" in item.keywords:
+            item.add_marker(skip_stress)