How to test directives in AngularJs?

Question

Angular

Looking for a working example using karma-ng-html2js-preprocessor.
There are many different examples on the Internet using this module, but I have not been able to launch any of them.
More precisely, I did not succeed in extracting data from the html file using karma-ng-html2js-preprocessor.
Therefore, please explain, using accessible, simple, and most importantly working examples, how to test the html directives of angular using this module.
Thanks in advance.