63 lines
2 KiB
HTML
63 lines
2 KiB
HTML
<!DOCTYPE HTML>
|
|
<head>
|
|
<title>Largest Contentful Paint: initially out-of-viewport image gets an LCP entry once they are visible.</title>
|
|
<script src="/resources/testharness.js"></script>
|
|
<script src="/resources/testharnessreport.js"></script>
|
|
<style>
|
|
.flex-container {
|
|
display: flex;
|
|
flex-direction: row;
|
|
width: 1000px;
|
|
overflow-x: hidden;
|
|
scroll-behavior: auto;
|
|
}
|
|
</style>
|
|
</head>
|
|
<body>
|
|
<div>
|
|
<div class='flex-container' id="container">
|
|
<img src='/images/lcp-100x50.png?pipe=trickle(d1)' width="1000" height="1000"/>
|
|
<img src='/images/lcp-1x1.png?1' width="1000" height="1000"/>
|
|
<img src='/images/lcp-1x1.png?2' width="1000" height="1000"/>
|
|
<img src='/images/lcp-1x1.png?3' width="1000" height="1000"/>
|
|
</div>
|
|
</div>
|
|
<script>
|
|
// Spin the carousel
|
|
setup({"hide_test_state": true});
|
|
const images = document.querySelectorAll('img');
|
|
|
|
let selected = 0;
|
|
const container = document.getElementById("container");
|
|
const transition = () => {
|
|
container.scrollLeft = selected * 1000;
|
|
selected = (selected + 1) % images.length;
|
|
}
|
|
|
|
container.scrollLeft=1000;
|
|
setInterval(transition, 1000);
|
|
|
|
promise_test(async t => {
|
|
|
|
return new Promise(resolve => {
|
|
assert_implements(window.LargestContentfulPaint,
|
|
"LargestContentfulPaint is not implemented");
|
|
const observer = new PerformanceObserver(entryList => {
|
|
entryList.getEntries().forEach(entry => {
|
|
// May receive a text entry. Ignore that entry.
|
|
if (!entry.url) {
|
|
return;
|
|
}
|
|
assert_true(entry.url.includes("lcp-100x50.png"), "Re-visible image has an entry");
|
|
resolve();
|
|
});
|
|
});
|
|
observer.observe({type: 'largest-contentful-paint', buffered: true});
|
|
t.step_timeout(() => {
|
|
assert_unreached("The image should have become visible by now, which should have triggered an LCP entry.");
|
|
t.done();
|
|
}, 2000);
|
|
});
|
|
}, 'Image visibility: out-of-viewport images are observable by LargestContentfulPaint once they become visible.');
|
|
</script>
|
|
</body>
|