anchoring-with-bounds-clamping.html
<!DOCTYPE html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
#changer { height: 1500px; }
#anchor {
width: 150px;
height: 1000px;
background-color: pink;
}
</style>
<div id="changer"></div>
<div id="anchor"></div>
<script>
// Test that scroll anchoring interacts correctly with scroll bounds clamping:
// There should be no visible jump even if the content shrinks such that the
// new max scroll position is less than the previous scroll position.
test(() => {
document.scrollingElement.scrollTop = 1600;
document.querySelector("#changer").style.height = "0";
assert_equals(document.scrollingElement.scrollTop, 100);
}, "Anchoring combined with scroll bounds clamping in the document.");
</script>