css/css-layout-api/box-tree-registered.https.html

<!DOCTYPE html>
<html class=reftest-wait>
<link rel="help" href="https://drafts.css-houdini.org/css-layout-api/#layout-api-box-tree">
<link rel="match" href="box-tree-registered-ref.html">
<meta name="assert" content="This test checks that a registered layout() has children which are blockified and new formatting contexts." />
<style>
@supports (display: layout(registered)) {
  .test {
    display: layout(registered);
  }
}

.container {
  margin: 20px 0;
  border: solid 2px;
  width: 100px;
}

.float {
  float: left;
  width: 50%;
  height: 50px;
}

.pink {
  background: hotpink;
}
</style>
<script src="/common/reftest-wait.js"></script>
<script src="/common/worklet-reftest.js"></script>

<div class="container">
  <!-- This tests that the "layout()" grandchildren floats within the don't interact with each other. -->
  <div class="test">
    <div class="inflow">
      <div class="float pink"></div>
    </div>
    <div class="inflow">
      <div class="float pink"></div>
    </div>
  </div>
</div>

<div class="container">
  <!-- This tests that the "layout()" children margins interact as if they are new formatting contexts. -->
  <div class="test">
    <div class="inflow pink">
      <div style="margin-bottom: 50px;"></div>
    </div>
    <div class="inflow pink">
      <div style="margin-top: 50px;"></div>
    </div>
  </div>
</div>

<script id="code" type="text/worklet">
registerLayout('registered', class {
  *intrinsicSizes() {}
  *layout() { throw Error(); }
});
</script>

<script>
importWorkletAndTerminateTestAfterAsyncPaint(CSS.layoutWorklet, document.getElementById('code').textContent);
</script>
</html>