It’s probably a bit easier to do the autotests on Mac through Firefox. If you look in your ChoiceScript folder, you’ll see quicktest.html and randomtest.html. You can open them in Firefox and run the autotests that way.
Another, even easier way, if you fancy giving it a go, is to download CSIDE. You can run the autotests from there with just a keyboard shortcut (and there are heaps of other useful features, too).
And, if you like, more info on the ChoiceScript wiki.