Simplify pytest setup

.github/workflows/test-gpu.yml

@@ -48,7 +48,7 @@ jobs:
         run: micromamba list
 
       - name: Run test
-        run: pytest --only-gpu --cov --cov-report=xml --cov-context=test -n 4
+        run: pytest -m gpu --cov --cov-report=xml --cov-context=test -n 4
 
       - uses: codecov/codecov-action@v3
         with:

conftest.py

@@ -3,23 +3,13 @@
 import pytest
 
 
-def pytest_addoption(parser):
-    parser.addoption(
-        "--only-gpu",
-        action="store_true",
-        default=False,
-        help="Only run GPU tests.",
-    )
+def pytest_itemcollected(item):
+    # Defniing behavior of pytest.mark.gpu
+    from importlib.util import find_spec
 
-
-def pytest_runtest_setup(item):
     gpu = len([mark for mark in item.iter_markers(name="gpu")]) > 0
 
-    if not gpu:  # Skip non gpu tests on gpu CI
-        if item.config.getoption("--only-gpu"):
-            pytest.skip("Only running GPU tests.")
-    else:  # Skip GPU tests if cupy not installed
-        from importlib.util import find_spec
-
-        if not find_spec("cupy"):
-            pytest.skip("Cupy not installed.")
+    if gpu:
+        item.add_marker(
+            pytest.mark.skipif(not find_spec("cupy"), reason="Cupy not installed.")
+        )