Merge pull request #3888 from AI-Hypercomputer:fix-parameterized-marker-ordering

PiperOrigin-RevId: 915544286

Author: Google-ML-Automation

tests/conftest.py

@@ -24,6 +24,48 @@
 import jax
 import importlib.util
 
+# --- Monkeypatch for absl.testing.parameterized ---
+# Context: Decorating a test method with @parameterized.named_parameters returns a custom
+# iterable container (_ParameterizedTestIter) instead of a standard function object.
+# Problem: When pytest markers are applied above @parameterized in the decorator stack:
+#
+#   @pytest.mark.cpu_only
+#   @parameterized.named_parameters(...)
+#   def test_foo(self, ...):
+#
+# pytest attaches the marker attributes exclusively to the outer iterable container object.
+# During class initialization, the test metaclass unwraps the base function to generate
+# individual test methods, omitting the outer container entirely. Consequently, marker
+# attributes attached to the outer container are dropped and lost before pytest collection.
+# Solution: Intercept _ParameterizedTestIter.__iter__ to dynamically propagate any discovered
+# pytestmark attributes from the outer container object down to all generated test methods.
+from absl.testing import parameterized
+
+try:
+  # pylint: disable=protected-access
+  _orig_iter = parameterized._ParameterizedTestIter.__iter__
+
+  def _custom_iter(self):
+    """Custom iterator propagating outer pytestmark attributes to generated test methods."""
+    outer_marks = getattr(self, "pytestmark", None)
+    if outer_marks is None:
+      yield from _orig_iter(self)
+    else:
+      if not isinstance(outer_marks, list):
+        outer_marks = [outer_marks]
+
+      for func in _orig_iter(self):
+        existing_marks = getattr(func, "pytestmark", [])
+        if not isinstance(existing_marks, list):
+          existing_marks = [existing_marks]
+        func.pytestmark = existing_marks + outer_marks
+        yield func
+
+  parameterized._ParameterizedTestIter.__iter__ = _custom_iter
+  # pylint: enable=protected-access
+except AttributeError:
+  pass
+
 try:
   _HAS_TPU = any(d.platform == "tpu" for d in jax.devices())
 except Exception:  # pragma: no cover  pylint: disable=broad-exception-caught

tests/unit/marker_propagation_test.py

@@ -0,0 +1,60 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Unit tests validating pytest marker propagation through decorator stacks."""
+
+import functools
+import unittest
+
+from absl.testing import parameterized
+import jax
+import pytest
+
+
+def dummy_decorator(func):
+  """Standard transparent wrapper decorator preserving function metadata."""
+
+  @functools.wraps(func)
+  def wrapper(*args, **kwargs):
+    return func(*args, **kwargs)
+
+  return wrapper
+
+
+class MarkerPropagationTest(parameterized.TestCase):
+  """Validates that pytest markers propagate correctly through decorator stacks."""
+
+  @pytest.mark.cpu_only
+  @parameterized.named_parameters(
+      {"testcase_name": "default", "unused": None},
+  )
+  def test_parameterized_cpu_only_marker_propagation(self, unused):
+    """Verifies cpu_only marker above @parameterized propagates to generated methods."""
+    has_tpu = any(d.platform == "tpu" for d in jax.devices())
+    has_gpu = any(d.platform == "gpu" for d in jax.devices())
+    assert not has_tpu, "cpu_only parameterized test accidentally executed on TPU hardware"
+    assert not has_gpu, "cpu_only parameterized test accidentally executed on GPU hardware"
+
+  @pytest.mark.cpu_only
+  @dummy_decorator
+  def test_standard_decorator_cpu_only_marker_propagation(self):
+    """Verifies cpu_only marker above standard decorators propagates correctly."""
+    has_tpu = any(d.platform == "tpu" for d in jax.devices())
+    has_gpu = any(d.platform == "gpu" for d in jax.devices())
+    assert not has_tpu, "cpu_only standard decorated test accidentally executed on TPU hardware"
+    assert not has_gpu, "cpu_only standard decorated test accidentally executed on GPU hardware"
+
+
+if __name__ == "__main__":
+  unittest.main()