Jasmine date mocking with moment.js

Question

I'm using moment.js for date/time in my application, but it seems like it doesn't play well with Jasmine's mocking capabilities. I've put together a test suite below that shows my issue:

jasmine.clock().mockDate doesn't seem to work for moment, while it works fine for Date.

describe('Jasmine tests', function () {     beforeEach(function() {         jasmine.clock().install();     });      afterEach(function() {         jasmine.clock().uninstall();     });      // Pass     it('uses the mocked time with Date', function() {         var today = new Date('2015-10-19');         jasmine.clock().mockDate(today);         expect(new Date().valueOf()).toEqual(today.valueOf());     });       // Fail     it('uses the mocked time with moment', function() {         var today = moment('2015-10-19');         jasmine.clock().mockDate(today);          expect(moment().valueOf()).toEqual(today.valueOf());     }); }); 

Why does Date work as expected while moment does not? Isn't moment using Date under the hood?

What is the right way to mock moment using Jasmine?

Answer 1

jasmine.clock().mockDate expects Date as input. Date and moment are not fully compatible. If you provide the to-be-mocked date in the spec itself you could simply use Date there instead.

If your code generates a moment you want to mock, or you'd rather use the moment API, take a look at moment.toDate(). This method returns the Date object backing a moment.

it('uses the mocked time with moment', function() {     var today = moment('2015-10-19').toDate();     jasmine.clock().mockDate(today);     expect(moment().valueOf()).toEqual(today.valueOf()); });