How to create Unit / NUnit / XUnit Tests for a Visual Studio Extension projects (VSIX) using Visual Studio 2017?

On VS 2015 you can test your VSIX projects using XUnit / NUnit / Basic Unit Tests from Visual Studio. Unfortunately, this way is not possible anymore in VS 2017 and VS 2019. Some attributes are now deprecated and I cannot find a replacement for them.

At this moment I am trying to find a way to test my VS Extensions using Visual Studio 2017. Any help is appreciated.

Thanks!