Support pytest markers regardless of decorator order

[igorts-git]

Description

The problem

Without this patch unit tests that set cpu_only would still execute on TPU and GPU machines if they are applied on top of a @parameterized.named_parameters(...) decorator.

For instance:

  @pytest.mark.cpu_only
  @parameterized.named_parameters(...)
  def test_foo(self, ...):

Solution

We ensure pytest markers that are applied above @parameterized.named_parameters are properly propagated to generated test methods during class metaclass expansion.

Tests

I added unit tests for validating marker propagation across both parameterized and standard decorator stacks.

To confirm that this unit test fails without applying the patch I created a separate PR with just the unit test and without the patch: #3887. We expect the test to fail on that PR and pass on this PR.

Checklist

Before submitting this PR, please make sure (put X in square brackets):

• I have performed a self-review of my code. For an optional AI review, add the gemini-review label.
• I have necessary comments in my code, particularly in hard-to-understand areas.
• I have run end-to-end tests tests and provided workload links above if applicable.
• I have made or will make corresponding changes to the doc if needed, including adding new documentation pages to the relevant Table of Contents (toctree directive) as explained in our documentation.

[codecov]

Codecov Report

❌ Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...t/integration/vllm/maxtext_vllm_adapter/adapter.py	0.00%	1 Missing ⚠️

📢 Thoughts on this report? Let us know!

[github-actions]

🤖 Hi @igorts-git, I've received your request, and I'm working on it now! You can track my progress in the logs for more details.

[github-actions]

## 📋 Review Summary

This Pull Request introduces a clever fix for pytest marker propagation issues when using @parameterized.named_parameters from absl-py. By monkeypatching the _ParameterizedTestIter class in conftest.py, it ensures that markers like @pytest.mark.cpu_only are correctly passed down to generated test methods regardless of their position in the decorator stack.

🔍 General Feedback

• The solution is elegant and addresses a significant pain point in the project's testing workflow.
• The inclusion of marker_propagation_test.py is highly appreciated as it empirically validates the fix.
• Minor suggestions were made to improve the robustness of the monkeypatching logic and simplify the attribute merging.

[github-actions]

🟢 Excellent addition of a dedicated test to verify marker propagation. This ensures the monkeypatch works as expected and provides a regression test for any future changes to the testing infrastructure.