css/css-contain/content-visibility/content-visibility-089.html

<!doctype HTML>
<html>
<meta charset="utf8">
<title>Content Visibility: clientLeft/clientTop/clientWidth/clientHeight measure correctly</title>
<link rel="author" title="Rob Buis" href="mailto:rbuis@igalia.com">
<link rel="help" href="https://drafts.csswg.org/css-contain/#content-visibility">
<meta name="assert" content="clientLeft/clientTop/clientWidth/clientHeight measure correctly in content-visibility hidden subtree">

<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<style>
body {
  margin: 0;
  padding: 0;
}
#outer {
  width: 100px;
  height: 100px;
  background: lightblue;

  content-visibility: hidden;
}
#inner {
  border-left: 25px black solid;
  border-top: 25px black solid;
  margin: 25px;
  width: 50px;
  height: 50px;
  background: lightgreen;
}
</style>

<body>
<div id="outer"><div id="inner"></div></div>
</body>

<script>
test(() => {
  const inner = document.getElementById("inner");
  assert_equals(inner.clientLeft, 25, "left");
  assert_equals(inner.clientTop, 25, "top");
  assert_equals(inner.clientWidth, 50, "width");
  assert_equals(inner.clientHeight, 50, "height");
});

</script>
</html>