<!DOCTYPE HTML> <meta charset=utf-8> <title>Largest Contentful Paint: largest image is reported.</title> <body> <script src="/resources/testharness.js"></script> <script src="/resources/testharnessreport.js"></script> <script src="resources/largest-contentful-paint-helpers.js"></script> <img id="target"/> <img id="target2"/> <script> setup({"hide_test_state": true}); const numInitial = 100; const sleep = 1000; const small_img_src = '/images/green-16x16.png'; let beforeLoad; async_test(function (t) { assert_implements(window.LargestContentfulPaint, "LargestContentfulPaint is not implemented"); const img_src = '/element-timing/resources/progressive-image.py?name=square20.jpg&numInitial=' + numInitial + '&sleep=' + sleep; const img1 = document.getElementById('target') img1.src = img_src; // After a brief wait, remove the image and add a smaller image to target2. t.step_timeout(() => { img1.parentNode.removeChild(img1); document.getElementById('target2').src = small_img_src; beforeLoad = performance.now(); }, 0); new PerformanceObserver( t.step_func(entryList => { let images = entryList.getEntries().filter(e => e.id !== ''); if (!images.length) return; assert_equals(images.length, 1, 'Should only receive one entry'); const entry = images[0]; checkImage(images[0], window.location.origin + small_img_src, 'target2', 16 * 16, beforeLoad); t.done(); }) ).observe({type: 'largest-contentful-paint', buffered: true}); }, 'Largest Contentful Paint: image removed before loaded does not produce entry.'); </script> </body>