Unfortunately, when some of those tests fail, error messages are not very helpful. Thus, I would like to debug them.
However, most sources that I've found suggest creating a separate configuration for debugging - configuration using Chrome (or another modern browser) to debug tests. For example: https://wannabeegeek.com/2017/04/07/debugging-jasmine-unit-tests-running-with-karma-runner-in-vs-code/ http://blog.mlewandowski.com/Debugging-Karma-tests-with-VSCode.html
Is it possible to run those tests in debug mode, step-by-step, using breakpoints without changing PhantomJS to Chrome?