AngularJS unit test controller with $locationChangeStart in it

I'm new to AngularJS Unit testing. I want to test a function in a controller with jasmine. In the same controller there is also a watch for $locationChangeStart

$scope.$on('$locationChangeStart', function(){
    $scope.killTimer($scope.timer);
});

I do not want to test this, but another function. Still when I try to run a test, I get an error, which points to the $scope.$on line:

TypeError: undefined is not a function

What should I do to make the test not run this line? I copy my test spec because I'm not sure if everything is OK there.

describe('invoiceListController', function() {
    beforeEach(module('invoice'));

    var $controller;

    beforeEach(inject(function(_$controller_){
        // The injector unwraps the underscores (_) from around the parameter names when matching
        $controller = _$controller_;
    }));

    var $scope, controller;

    beforeEach(function() {
        $scope = {};
        controller = $controller('invoiceList', { $scope: $scope });
    });

    describe('deleteInvoices()', function(){
        it('should do nothing when no invoice is selected', function() {
            $scope.invoicesToDelete = false;
            var response = $scope.deleteInvoices();
            expect(response).toEqual(false);
        });
    });
});

And the code I want to test:

$scope.deleteInvoices = function(){
    if($scope.invoicesToDelete) {
        return true;
    } else {
        return false;
    }
};