Mock date constructor with Jasmine

Question

I\'m testing a function that takes a date as an optional argument. I want to assert that a new Date object is created if the function is called without the argument.

Answer 1

For the users who are using Edge version of Jasmine:

it('Should spy on Date', function() {
    var oldDate = Date;

    // and.callFake
    spyOn(window, 'Date').and.callFake(function() {
        return new oldDate();
    });

    var d = new Date().toISOString;

    expect(window.Date).toHaveBeenCalled();
});