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Test Info:

<!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 {
display: inline-block;
overflow-y: scroll;
height: 200px;
border: 3px solid black;
}
#target {
width: 100px;
height: 100px;
background-color: green;
}
.spacer {
height: 300px;
}
</style>
<div id="root">
<div id="leading-space" class="spacer"></div>
<div id="target"></div>
<div id="trailing-space" class="spacer"</div>
</div>
<script>
var entries = [];
var root, target, trailingSpace;
runTestCycle(function() {
target = document.getElementById("target");
assert_true(!!target, "Target exists");
trailingSpace = document.getElementById("trailing-space");
assert_true(!!trailingSpace, "TrailingSpace exists");
root = document.getElementById("root");
assert_true(!!root, "Root 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");
}, "Verify that not-intersecting notifications are sent when a target is removed from the DOM tree.");
function step0() {
root.scrollTop = 150;
runTestCycle(step1, "root.scrollTop = 150");
checkLastEntry(entries, 0, [11, 111, 311, 411, 0, 0, 0, 0, 11, 111, 11, 211, false]);
}
function step1() {
root.removeChild(target);
runTestCycle(step2, "root.removeChild(target).");
checkLastEntry(entries, 1, [11, 111, 161, 261, 11, 111, 161, 211, 11, 111, 11, 211, true]);
}
function step2() {
root.scrollTop = 0;
root.insertBefore(target, trailingSpace);
runTestCycle(step3, "root.insertBefore(target, trailingSpace).");
checkLastEntry(entries, 2, [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, false]);
}
function step3() {
root.scrollTop = 150;
runTestCycle(step4, "root.scrollTop = 150 after reinserting target.");
checkLastEntry(entries, 2);
}
function step4() {
checkLastEntry(entries, 3, [11, 111, 161, 261, 11, 111, 161, 211, 11, 111, 11, 211, true]);
}
</script>