[parthea]

Towards b/578989906

[gemini-code-assist]

Code Review

This pull request introduces a new Cloud Build configuration (ci/cloudbuild/system-test.yaml) to run system tests in shards, featuring an inline Python script to filter packages and a pytest shim to handle Google Application Credentials. The review feedback highlights two important issues: first, a potential mismatch in package path filtering due to trailing slashes that could silently skip tests, and second, a risk of unexpected module shadowing caused by a trailing colon in PYTHONPATH when it is initially empty.

[gemini-code-assist]

There is a potential mismatch between the package paths returned by get_package_shards.py and the filtered ENABLED_PACKAGES. Adding a trailing slash + "/" to the enabled set while checking p in enabled (where p might not have a trailing slash) will cause the check to fail. This results in gps.get_packages() returning an empty list, which silently skips all system tests and reports an immediate green build.

To prevent this, normalize both the enabled packages and the package paths from orig_get_packages() by stripping trailing slashes before comparison.

      enabled = {
          p.strip().rstrip("/")
          for p in os.environ.get("ENABLED_PACKAGES", "").replace(",", " ").split()
          if p.strip()
      }
      if enabled:
          orig_get_packages = gps.get_packages
          gps.get_packages = lambda: [p for p in orig_get_packages() if p.strip().rstrip("/") in enabled]