Showcase: Use sphinx-test-reports JUnit XML properties for requirement traceability

[arnoox]

Summary

Demonstrate the new sphinx-test-reports feature that maps JUnit XML <properties> to sphinx-needs fields, enabling automatic requirement traceability from test results.

Background

sphinx-test-reports now supports extracting <properties> elements from JUnit XML and mapping them to sphinx-needs fields. This allows test frameworks (pytest, JUnit 5, Maven Surefire, etc.) to embed requirement IDs directly in test output, which then appear as traceable links in the documentation.

What to implement

1. Add <properties> to the coffee-machine JUnit XML (docs/testsuites/coffee_machine_junit.xml):

<testcase classname="interfaces::tests::test_brew_ctrl_status_fault_detection" name="TEST_SAFETY_SHUTDOWN" time="0.001">
  <properties>
    <property name="verifies" value="SWREQ_SAFE_SHUTDOWN"/>
  </properties>
</testcase>

2. Configure conf.py with the new options:

# Make these JUnit properties available as sphinx-needs fields
tr_extra_options = ["verifies"]

# Map the "verifies" property to sphinx-needs links
tr_property_link_types = {
    "verifies": "links",
}

3. Verify that the rendered test-run needs automatically link back to the requirements they verify, creating a full traceability chain from requirement → test case → test result.

Acceptance Criteria

• coffee_machine_junit.xml contains <properties> with verifies entries pointing to existing requirement IDs
• conf.py has tr_extra_options and tr_property_link_types configured
• make html builds without errors
• Rendered test-run needs show links back to the requirements they verify

References

• Feature PR: feat: link JUnit XML properties to sphinx-needs fields sphinx-test-reports#135
• sphinx-test-reports docs: https://sphinx-test-reports.readthedocs.io/

[arnoox]

If possible, we should always put configuration into ubproject.toml