css/css-backgrounds/border-width-cssom.html

<!DOCTYPE html>
<html>
<head>
<title>CSS Borders: CSSOM for border-*-width: thin, medium, thick</title>
<link rel="help" href="https://drafts.csswg.org/css-backgrounds-3/#border-width">
<meta name="assert" content="getComputedStyle() for 'border-*-width' with values thin, medium, thick, returns 1px, 3px, and 5px, respectively." />
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
.thin { border: solid thin; }
.medium { border: solid medium; }
.thick { border: solid thick; }
</style>
</head>
<body>
  <div class=thin data-expected=1px></div>
  <div class=medium data-expected=3px></div>
  <div class=thick data-expected=5px></div>
  <script>
    let divs = document.querySelectorAll('div');
    let props = ['border-top-width', 'border-right-width', 'border-bottom-width', 'border-left-width'];
    for (let div of divs) {
      let style = getComputedStyle(div);
      for (let prop of props) {
        test(() => {
          assert_equals(style.getPropertyValue(prop), div.dataset.expected);
        }, `${prop}: ${div.className} is ${div.dataset.expected}`);
      }
    }
  </script>
</body>
</html>