css/css-layout-api/constraints-data-function-failure.https.html

<!DOCTYPE html>
<html class=reftest-wait>
<link rel="help" href="https://drafts.css-houdini.org/css-layout-api/#dom-layoutconstraints-data">
<link rel="match" href="green-square-ref.html">
<meta name="assert" content="This test checks that a function can't be passed to a child layout." />
<style>
.test {
  background: red;
  width: 100px;
}

@supports (display: layout(parent)) {
  .test {
    display: layout(parent);
    background: green;
  }

  .child {
    display: layout(child);
  }
}
</style>
<script src="/common/reftest-wait.js"></script>
<script src="/common/worklet-reftest.js"></script>

<div class="test">
  <div class="child"></div>
</div>

<script id="code" type="text/worklet">
registerLayout('parent', class {
  *intrinsicSizes() {}
  *layout() {}
  *layout([child], edges, constraints, styleMap) {
    let childFragment = null;

    try {
      childFragment = yield child.layoutNextFragment({
        data: { fn: function() {} }
      });
    } catch(e) {
      // Success! The structured cloning algorithm should have thrown an error.
      childFragment = yield child.layoutNextFragment({});
      return {autoBlockSize: 100, childFragments: [childFragment]};
    }

    return {autoBlockSize: 0, childFragments: [childFragment]};
  }
});

registerLayout('child', class {
  *intrinsicSizes() {}
  *layout() {}
  *layout() {
    return {autoBlockSize: 0};
  }
});
</script>

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