Support testing np and tnp on the same test

Rudimentary example of usage in `test_indexing.py`

Author: honno

torch_np/tests/conftest.py

@@ -22,6 +22,15 @@ def __getattribute__(self, attr):
         sys.modules["numpy"] = Inaccessible()
 
 
+def pytest_generate_tests(metafunc):
+    import numpy as np
+
+    import torch_np as tnp
+
+    if "np" in metafunc.fixturenames:
+        metafunc.parametrize("np", [np, tnp])
+
+
 def pytest_collection_modifyitems(config, items):
     if not config.getoption("--runslow"):
         skip_slow = pytest.mark.skip(reason="slow test, use --runslow to run")