css/css-flexbox/dynamic-change-simplified-layout.html

<!DOCTYPE html>
<link rel="match" href="../reference/ref-filled-green-100px-square.xht" />
<link rel="author" title="Google LLC" href="http://www.google.com" />
<link rel="help" href="https://drafts.csswg.org/css-flexbox/#cross-sizing" />
<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=992010" />
<title>Tests that certain dynamic changes don't lead to a flex item being sized as shrink to fit when it should stretch in the cross axis</title>

<style>
#flex {
  display: flex;
  flex-direction: column;
  flex-wrap: wrap;
  position: absolute;
  top: 20px;
  width: 100px;
}

#it1 {
  background: green;
  flex: none;
  height: 100px;
  min-height: 0;
  position: relative;
}

#child {
  position: absolute;
  top: 0;
  left: 0;
}
</style>

<p>Test passes if there is a filled green square and <strong>no red</strong>.</p>

<div style="position: relative;">
  <div id="flex">
    <div id="it1" style=""><div id="child"></div></div>
    <div id="it2"></div>
  </div>
</div>

<script>
var flex = document.getElementById("flex");
flex.offsetWidth;
var it2 = document.getElementById("it2");
it2.style.width = "50px";
flex.offsetWidth;
flex.style.top = "0px";
var child = document.getElementById("child");
child.style.top = "1px";
flex.offsetWidth;
</script>