Mock Timezone in PhantomJS for Jasmine Test

Question

Is it possible to mock a timezone in Jasmine to test a date object?

I have a function which takes A UTC time string and converts it to a date object.

Using "2016-01-16T07:29:59+0000", I want to be able to verify that when we are in PST we are observing 2016-01-15 23:29:59 as the local date/time

I'd like to be able to switch this time zone back to GMT and then ensure that we observe 2016-01-16 07:29:59 as the local date/time

(How) is this possible? (I am running my Jasmine spec through Grunt with phantomjs)

My function for reference:

utcDateStringToDateObject: function(dateString){
    return dateString.indexOf('+')>-1 ? new Date(dateString.split('+')[0]) : new Date(dateString);
}

Answer 1

I am using jasmine 3.4.0, one solution is to use the clock

    beforeEach(() => {
        jasmine.clock().install();
        // whenever new Date() occurs return the date below
        jasmine.clock().mockDate(new Date('2024-04-08T06:40:00'));
    });

    afterEach(() => {
        jasmine.clock().uninstall();
    });

However, since my tests included timezones, I had to spyOn my service

it('should support work', () => {
        const mocked = moment.tz('2019-03-27 10:00:00', 'America/New_York');
        spyOn(spectator.service, 'getMoment').and.returnValue(mocked);
        const output = spectator.service.foo('bar');
        // My asserts
        expect(output.start.format(dateFormat)).toBe('2019-03-17T00:00:00-04:00');
        expect(output.end.format(dateFormat)).toBe('2019-03-23T23:59:59-04:00');
    });