<!DOCTYPE html>
<html>
  <meta charset="utf-8" />
  <meta name="viewport" content="width=device-width, user-scalable=no" />
  <style>
    html {
      height: 100%;
      width: 100%;
      /* background contains one extra transparent.gif because we want trick the
     contentful paint detection; We want to make sure the background is loaded
     before the test starts so we always wait for the contentful paint timestamp
     to exist, however, gradient isn't considered as contentful per spec, so Gecko
     wouldn't generate a timestamp for it. Hence, we added a transparent gif
     to the image list to trick the detection. */
      background: url("/assets/www/transparent.gif"),
        linear-gradient(135deg, red, white);
    }
    body {
      width: 100%;
      margin: 0px;
      padding: 0px;
    }
  </style>
  <body>
    <div style="width: 100%; height: 100vh; background-color: green"></div>
    <script>
      if (document.location.search.startsWith("?event")) {
        document.querySelector("div").addEventListener("touchstart", e => {
          if (document.location.search == "?event-prevent") {
            e.preventDefault();
          }
        });
      }
    </script>
  </body>
</html>
