Add tests coverage for new files moved over from generator shared source

[annelo-msft]

Per #38286 (review), new files added from generator shared source in #38286 don't have complete test coverage. This issue tracks the work to add test coverage for those files.

[github-actions]

Hi @annelo-msft, we deeply appreciate your input into this project. Regrettably, this issue has remained unresolved for over 2 years and inactive for 30 days, leading us to the decision to close it. We've implemented this policy to maintain the relevance of our issue queue and facilitate easier navigation for new contributors. If you still believe this topic requires attention, please feel free to create a new issue, referencing this one. Thank you for your understanding and ongoing support.