LayoutTests/fast/inline/empty-inline-box-bounding-rect.html

<style>
.container {
  width:100px;
}

.float-text {
  float: left;  
  width: 100%;
  height: 20px;
  background-color: green;
}
</style>
<div class=container>somtextsome<div class="float-text"></div><span id=span> more</span></div>
<pre id=result></pre>
<script>
window.testRunner?.dumpAsText();

function checkForEmptyRects() {
  const span = document.getElementById('span');
  const rects = span.getClientRects();
  const result = document.getElementById('result');

  for (let i = 0; i < rects.length; i++) {
    const rect = rects[i];
    if (rect.width === 0 && rect.height === 0) {
      result.textContent = 'FAIL: Found empty rect with width=0 and height=0\n';
      result.textContent += 'All rects:\n';
      for (let j = 0; j < rects.length; j++) {
        result.textContent += `Rect ${j}: width=${rects[j].width}, height=${rects[j].height}, x=${rects[j].x}, y=${rects[j].y}\n`;
      }
      return;
    }
  }

  result.textContent = 'PASS: No empty rects found';
}

checkForEmptyRects();
</script>