Jasmine unit test spec for my code. I am using Durandal and Knockout

Question

I am very new to Jasmine unit test. I have pasted my code below. But not sure what i am doing wrong inside spec.Can you guys please guide me on the same.

var subscription = self.selectedEmpList.subscribe(function (selectedEmpList) {
            if (selectedEmpList) {
                dataService.getEmpsByEmpList(self.viewData.EmpId, selectedEmpList.id)
                .done(loadEmpSpread);
            }

Corresponding Spec what I am trying from whatever I got from googling.

var clickSelectedEmpList = null;
var empListSpy = null;

beforeEach(function () {
        fil = new filter();
        empListSpy = jasmine.createSpyObj("empListSpy", ["subscribe"]);
    });
it('should be activatable', function () {
        fil.activate(fixture.filterActivationData);               
        empListSpy.subscribe.and.callFake(function (selectedEmpList) {
            clickSelectedEmpList = selectedEmpList;
        });
        clickSelectedEmpList();

    });

And this is failed with error:-

TypeError: 'undefined' is not an object <evaluating 'empListSpy.subscribe.and.callFake'>