servo/tests/wpt/web-platform-tests/largest-contentful-paint/first-letter-background.html

34 lines
1.2 KiB
HTML

<!DOCTYPE HTML>
<meta charset=utf-8>
<title>Largest Contentful Paint: observe element with background image in its first letter</title>
<body>
<style>
#target::first-letter {
background-image: url('/images/black-rectangle.png');
}
</style>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/largest-contentful-paint-helpers.js"></script>
<script>
async_test(function (t) {
if (!window.LargestContentfulPaint) {
assert_unreached("LargestContentfulPaint is not implemented");
}
const beforeLoad = performance.now();
const observer = new PerformanceObserver(
t.step_func(function(entryList) {
entryList.getEntries().forEach(entry => {
// If we happen to get a text entry due to text happening before the image, return.
if (entry.url === '')
return;
const url = window.location.origin + '/images/black-rectangle.png';
checkImage(entry, url, 'target', 0, beforeLoad, ['sizeLowerBound']);
t.done();
})
}));
observer.observe({entryTypes: ['largest-contentful-paint']});
}, 'Largest Contentful Paint: first-letter is observable.');
</script>
<div id='target'>A</div>
</body>