css/css-layout-api/fallback-constructor-error.https.html

<!DOCTYPE html>
<html class=reftest-wait>
<link rel="help" href="https://drafts.css-houdini.org/css-layout-api/#get-a-layout-class-instance">
<link rel="match" href="fallback-ref.html">
<meta name="assert" content="This test checks that a layout() class with a throwing constructor will fallback to block layout." />
<style>
.test {
  background: red;
  border: solid 2px;
  width: 100px;
}

.float {
  float: left;
  width: 50%;
  height: 100px;
}

.fc {
  display: flow-root;
  height: 100px;
}

@supports (display: layout(throwing-ctor)) {
  .test {
    display: layout(throwing-ctor);
    background: green;
  }
}
</style>
<script src="/common/reftest-wait.js"></script>
<script src="/common/worklet-reftest.js"></script>

<!-- This tests that when the "layout()" constructor fails, it will fallback to block layout. -->
<div class="test">
  <div class="float"></div>
  <div class="fc"></div>
</div>

<script id="code" type="text/worklet">
registerLayout('throwing-ctor', class {
  constructor() { throw Error('fail!'); }
  *intrinsicSizes() {}
  *layout() {}
});
</script>

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