How to know if a package from Node Package Management (NPM) is tested

My relatively now to Node.js and NPM, and I have a kind of naive question. I would like to know if there is a way to know if package published on NPM is tested, and if there is away could we automate that process, and if there is tool or framwork that tell me this packages is tested. Also, does NPM require developers to provide a test for their packages.

Thank you