css/css-multicol/multicol-span-all-dynamic-add-013.html

<!DOCTYPE html>
<html class="reftest-wait">
  <meta charset="utf-8">
  <title>CSS Multi-column Layout Test: Insert a block into a multicol details containing column-span:all</title>
  <link rel="author" title="Ting-Yu Lin" href="mailto:tlin@mozilla.com">
  <link rel="author" title="Mozilla" href="http://www.mozilla.org/">
  <link rel="help" href="https://drafts.csswg.org/css-multicol-1/#column-span">
  <link rel="match" href="multicol-span-all-dynamic-add-013-ref.html">
  <meta name="assert" content="This test checks that <summary> is still rendered as the first element after inserting a block into multicol <details>, at the place before <summary>.">

  <script>
  function runTest() {
    document.body.offsetHeight;

    // Create a div, and insert it as the first child of <details>,
    // just before <summary>.
    var block1 = document.createElement("div");
    var block1Text = document.createTextNode("block1");
    block1.appendChild(block1Text);

    var details = document.getElementById("details");
    details.insertBefore(block1, details.children[0]);

    document.documentElement.removeAttribute("class");
  }
  </script>

  <style>
  #details {
    column-count: 3;
    column-rule: 6px solid;
    width: 400px;
    outline: 1px solid black;
  }
  h3 {
    column-span: all;
    outline: 1px solid blue;
  }
  </style>

  <body onload="runTest();">
    <details open id="details">
      <summary>Summary</summary>
      <h3>spanner</h3>
      <div>block2</div>
    </details>
  </body>
</html>