To understand the concept of behavior checking, let's revisit an example presented in Chapter 3, Testing Frontend Code, and test the observable behavior of NewInvestmentView:
describe("and when an investment is created", function() {
var callbackSpy;
var investment;
beforeEach(function() {
callbackSpy = jasmine.createSpy('callback');
view.onCreate(callbackSpy);
investment = view.create();
});
it("should invoke the 'onCreate' callback with the investment",function() {
expect(callbackSpy).toHaveBeenCalled();
expect(callbackSpy).toHaveBeenCalledWith(investment);
});
});During the spec setup, it creates a new Jasmine Spy using the jasmine.createSpy function while passing a name for it (callback), then it sets this spy as an observer of the View's create event using the onCreate function, and finally it invokes the create function to create a new investment.
Later on at the expectations, the spec uses the matcher's toHaveBeenCalled and toHaveBeenCalledWith...