Debugging angular-cli project karma tests. Possible?

I'm using AngularJS 2 with angular-cli commands. Angluar-cli is the latest angular-cli@1.0.0-beta.26 version. What I'm trying to do, is to debug the project tests. Unittests with jasmine are the priority for me, but protractor would also be nice.

Of course the project is written in TypeScript and compiled to JS with webpack - the normal angular-cli way with no modifications.

Whereas I'm fully able to RUN the tests with karma in WebStorm (which is cool), I'd like to debug them as well, just like I was able to do it in the projects without TypeScript.

However, it never gets into the breakpoints and the tests just run uninterrupted (they run correctly). I set the breakpoints in the .ts files.

Am I doing something wrong, is it possible at all? This is my config (the warning about karma path is just for the screenshot as I didn't want to show full path):

Thanks for any help.