Testing Date with sinon using fakeTimers and spies

dateTest.spec.js

const sinon = require('sinon');
const { expect } = require('chai');

describe('Timer', () => {
	it('should verify Date constructor called', () => {
		let dateSpy = sinon.spy(global, 'Date');
		const date = new Date();
		expect(dateSpy.calledWithNew()).to.be.true;
		dateSpy.restore();
	});
	
	it('should verify Date object using fakeTimer', () => {
		const expectedDate = new Date();
		expectedDate.setTime(expectedDate.getTime() + 1000)
		const clock = sinon.useFakeTimers(expectedDate.getTime());
		const actualTime = new Date();
		expect(actualTime.getTime()).to.equal(clock.now);
		clock.restore();
	});
});