QUnit.test( 'bgLazyLoad', function( assert ) { let done = assert.async(); let carousel = document.querySelector('.carousel--bg-lazyload'); let flkty = new Flickity( carousel, { bgLazyLoad: 1, } ); let loadCount = 0; flkty.on( 'bgLazyLoad', function( event, elem ) { loadCount++; assert.equal( event.type, 'load', 'event.type == load' ); assert.ok( elem, 'elem argument there' ); // after first 2 have loaded, select 7th cell if ( loadCount === 2 ) { flkty.select( 6 ); } if ( loadCount === 5 ) { let loadedImgs = carousel.querySelectorAll('.flickity-bg-lazyloaded'); assert.equal( loadedImgs.length, '5', 'only 5 images loaded' ); done(); } } ); } );