chromium/third_party/blink/web_tests/external/wpt/css/css-text/white-space/textarea-break-spaces-001.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Text level 3 Test: preserved white space at the end of line is wrapped when white-space is break-spaces in a textarea</title>
<link rel="author" title="Florian Rivoal" href="http://florian.rivoal.net/">
<link rel="help" href="https://drafts.csswg.org/css-text-3/#white-space-phase-2">
<link rel="help" href="https://drafts.csswg.org/css-text-3/#valdef-white-space-break-spaces">
<link rel="match" href="reference/textarea-pre-wrap-001-ref.html">
<meta name="assert" content="preserved white space at the end of the line is wrapped when the white-space property is set to break-spaces in a textarea.">
<link rel="stylesheet" type="text/css" href="/fonts/ahem.css" />
<style>
textarea {
  word-wrap: initial; /*deprecated alias*/
  overflow-wrap: initial;
  line-break: initial;
  word-break: initial;
  margin: 0;
  padding: 0;
  border: none;
  outline: none;
  resize: none;
  overflow: hidden; /* I don't want scrollbars, and overflow:visible isn't typically supported on textarea */

  font-size: 20px;
  font-family: Ahem;
  line-height: 1em;
  white-space: break-spaces;
  color: green;

  background: linear-gradient(red, red) 1ch 0/2ch 2ch no-repeat;

  width: 4ch;
  margin-left: -1ch;
}
</style>
<body>
  <p>Test passes if there is a <strong>filled green square</strong> and <strong>no red</strong>.</p>
  <textarea> XX  XX</textarea>
</body>