<!DOCTYPE html>
<title>The fieldset element: block formatting context</title>
<script src=/resources/testharness.js></script>
<script src=/resources/testharnessreport.js></script>
<style>
* {
  margin: 0;
  padding: 0;
}
fieldset { border: none; }
.float {
  float: left;
  width: 50px;
  height: 50px;
  background-color: orange;
}
</style>

<div class=float></div>
<fieldset><div class=float></div></fieldset>

<script>
test(() => {
  const fieldset = document.querySelector('fieldset');
  assert_equals(fieldset.offsetTop, 0, 'fieldset.offsetTop');
  assert_equals(fieldset.offsetLeft, 50, 'fieldset.offsetLeft');
  assert_equals(fieldset.clientHeight, 50, 'fieldset.clientHeight');
});
</script>