Clarification on Unit Testing Requirements for File Submissions

Hello maintainers,

I hope you're doing well! I wanted to ask for clarification regarding the requirements for unit tests in file submissions. Specifically, are unit tests mandatory for all new file additions and modifications in this repository? If so, I would like to understand the guidelines or best practices you recommend for writing these tests.

I am interested in contributing by writing unit tests for files that may not have them yet or improving the coverage of existing tests. Please let me know if this would be a valuable contribution to the project and if there are any specific areas or files that need attention.

Thank you for your time and for maintaining this repository!