mozilla-release/testing/web-platform/tests/vibration/pattern-array-extra-manual.html

<!DOCTYPE html>
<html>
  <head>
    <meta charset='utf-8'/>
    <title>Vibration API: test a pattern array parameter to vibrate() with an extra (even) item</title>
    <link rel='author' title='Robin Berjon' href='mailto:robin@berjon.com'/>
    <link rel='help' href='http://www.w3.org/TR/vibration/#methods'/>
    <meta name='flags' content='dom, interact'/>
    <meta name='assert' content='If the length of pattern is even, then remove the last entry in pattern.'/>
  </head>
  <body>
    <h1>Description</h1>
    <p>
      After hitting the button below, your device must vibrate three times for one second, separated
      by one second intervals.
    </p>
    <button id='vib'>Vibrate!</button>
    <script>
      if (undefined !== navigator.vibrate) {
          document.getElementById("vib").onclick = function () {
              navigator.vibrate([1000, 1000, 1000, 1000, 1000, 1000]);
          };
      }
    </script>
  </body>
</html>