css/css-layout-api/layout-child/inlines-dynamic.https.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Layout API: Dynamic blockification of inline children</title>
<link rel="author" href="mailto:obrufau@igalia.com" title="Oriol Brufau">
<link rel="help" href="https://drafts.css-houdini.org/css-layout-api/#layout-children" title="4.1. Layout Children">
<meta name="assert" content="This test checks that inline children are correctly blockified or unblockified when the display of the parent changes dynamically." />

<style>
#wrapper {
  display: layout(foo);
}
#test {
  display: inline;
}
</style>

<div id="wrapper">
  <div id="test">Lorem ipsum</div>
</div>

<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/common/worklet-reftest.js"></script>
<script>
promise_test(async function() {
  await importWorklet(CSS.layoutWorklet, {url: 'support/layout-child-worklet.js'});

  const wrapper = document.getElementById("wrapper");
  const test = document.getElementById("test");

  assert_equals(getComputedStyle(test).display, "block", "The child should have been blockified by the custom layout");

  wrapper.style.display = "block";
  assert_equals(getComputedStyle(test).display, "inline", "The child should no longer be blockified in block layout");

  wrapper.style.display = "";
  assert_equals(getComputedStyle(test).display, "block", "The child should have been blockified again");
});
</script>