import { throttle } from '../../src/js/utils/time'; describe( 'Time function ', () => { test( '"throttle" should reduce frequency of a callback function.', done => { const callback = jest.fn(); const throttled = throttle( callback, 40 ); let counter = 0; const intervalID = setInterval( () => { counter++; throttled(); if ( counter >= 10 ) { expect( callback ).toHaveBeenCalledTimes( 4 ); clearInterval( intervalID ); done(); } }, 20 ); } ); } );