css/css-overflow/text-overflow-scroll-rtl-001.html

<!DOCTYPE html>
<html class="reftest-wait">
<meta charset="utf-8">
<title>CSS Overflow: text-overflow: ellipsis and scrolling RTL</title>
<link rel="author" title="Manuel Rego Casasnovas" href="mailto:rego@igalia.com">
<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#ellipsis-scrolling">
<link rel="match" href="reference/text-overflow-scroll-rtl-001-ref.html">
<meta name="flags" content="should">
<meta name="assert" content="If you scroll an element with 'text-overflow: ellipsis' in RTL, the ellipsis should move to the new position.">
<link rel="stylesheet" type="text/css" href="/fonts/ahem.css" />
<style>
  div {
    font: 100px/1 Ahem;
    white-space: pre;
    width: 400px;
    overflow: hidden;
    text-overflow: ellipsis;
    direction: rtl;
  }
</style>

<p>The test passes if it matches the reference.</p>

<div id="test1">ppp pp p</div>
<div id="test2">ppp pp p</div>
<div id="test3"><span style="padding-inline-start: 400px;">ppp pp p</span></div>
<div id="test4"><span style="padding-inline-start: 600px;">ppp pp p</span></div>

<script>
  requestAnimationFrame(() => requestAnimationFrame(() => {
    test1.scrollLeft = -200;
    test2.scrollLeft = -400;
    test3.scrollLeft = -200;
    test4.scrollLeft = -1000;
    document.documentElement.className = "";
  }));
</script>