Ng test in non Angular project (NPM package)

In my current company they have created some private company-made npm packages that are in their private repository and are installed in many internal angular projects by using angular 8+ applications and are referenced as: git+ssh://gitURL/gitpPrject/projectName.git#branch

They want now to run unit testing in all those npm private packages, so with angular we would use ng test that excecutes Karma and Jasmine. I have tried running Ng Test and it tells me that ng test is only available in Angular projects.

So how can I test npm packages itselves?

Thanks