<!DOCTYPE html>
<meta name="viewport" content="width=device-width,initial-scale=1">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="./resources/intersection-observer-test-utils.js"></script>
<style>
pre, #log {
position: absolute;
top: 0;
left: 200px;
}
#root {
width: 200px;
height: 200px;
overflow: visible;
}
#target {
background-color: green;
}
</style>
<div id="root">
<div id="target" style="width: 100px; height: 100px; transform: translateY(250px)"></div>
</div>
<script>
var entries = [];
runTestCycle(function() {
var root = document.getElementById('root');
assert_true(!!root, "root element exists.");
var target = document.getElementById('target');
assert_true(!!target, "target element exists.");
var observer = new IntersectionObserver(function(changes) {
entries = entries.concat(changes);
}, { root: root });
observer.observe(target);
entries = entries.concat(observer.takeRecords());
assert_equals(entries.length, 0, "No initial notifications.");
runTestCycle(step0, "First rAF.");
}, "IntersectionObserver should detect and report edge-adjacent and zero-area intersections.");
function step0() {
runTestCycle(step1, "Set transform=translateY(200px) on target.");
checkLastEntry(entries, 0, [8, 108, 258, 358, 0, 0, 0, 0, 8, 208, 8, 208, false]);
target.style.transform = "translateY(200px)";
}
function step1() {
runTestCycle(step2, "Set transform=translateY(201px) on target.");
checkLastEntry(entries, 1, [8, 108, 208, 308, 8, 108, 208, 208, 8, 208, 8, 208, true]);
target.style.transform = "translateY(201px)";
}
function step2() {
runTestCycle(step3, "Set transform=translateY(185px) on target.");
checkLastEntry(entries, 2);
target.style.height = "0px";
target.style.width = "300px";
target.style.transform = "translateY(185px)";
}
function step3() {
checkLastEntry(entries, 3, [8, 308, 193, 193, 8, 208, 193, 193, 8, 208, 8, 208, true]);
}
</script>