Conditionally load ngMock into app only if running karma jasmine tests

I am having issues loading my app when including ngMock, so I would like to only load it when I am running my tests as this works fine. Is there a flag or some kind of isTesting() function that gets set when karma runs tests? Something I can then reference when creating the array of dependencies for my app.

I ended up just checking for the existence of a global variable which would only be set if the test classes had loaded, I suppose it's kind of obvious but I was kind of hoping for a karma.isRunning property or something...

Anyway my solution looks kind of like:

var dependencies = [
    'ui.router',
    'ngAnimate',
    'ngSanitize',
];
if (typeof APP_TEST !== "undefined")
    dependencies.push("ngMock");

angular.module('MyApp', dependencies)...

Keep in mind that the test classes need to be loaded before the main app files