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<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<title>Detect simple soft navigation.</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/resources/testdriver.js"></script>
<script src="/resources/testdriver-vendor.js"></script>
<script src="resources/soft-navigation-helper.js"></script>
<link rel="stylesheet" type="text/css" href="/fonts/ahem.css" />
</head>
<body>
<main id=main>
<div>
<a id=link><img src="/images/lcp-256x256.png"></a>
</div>
</main>
<script>
const link = document.getElementById("link");
testSoftNavigation({
addContent: async () => {
// Add an LCP element, large enough to trigger the Soft Navigation
// heuristics.
const p = addTextParagraphToMain("Lorem Ipsum", /*element_timing=*/"lcp");
p.id = "first_lcp";
// Once the first element is fully painted.
const observer = new PerformanceObserver(list => {
// Add a larger element to be the new LCP.
window.lcp_observer_promise = new Promise(resolve => {
(new PerformanceObserver(resolve)).observe({type: "element"});
});
const p2 = addTextParagraphToMain("LOREM IPSUMER", "real_lcp");
p2.id = "real_lcp";
observer.disconnect();
});
observer.observe({type: "element", buffered: true});
},
link: link,
validate: async () => {
await window.lcp_observer_promise;
const lcps = await getLcpEntries();
assert_greater_than_equal(lcps.length, 3, "Got at least 3 LCP entries");
assert_equals(lcps[lcps.length - 2].id, "first_lcp", "Got the first LCP");
assert_equals(lcps[lcps.length - 1].id, "real_lcp", "Got the real LCP");
},
test: "Test that an image LCP followed by 2 smaller soft navigation LCPs"
+ " properly queues both LCP entries, even when the soft navigation"
+ " is detected in between them."});
</script>
</body>
</html>
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