<!DOCTYPE HTML>
<html>
<head>
  <meta charset="utf-8">
  <title>content attribute changes among multiple meta viewport tags</title>
  <script src="/tests/SimpleTest/SimpleTest.js"></script>
  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
  <meta id="first" name="viewport" content="width=980">
  <meta id="second" name="viewport" content="width=device-width, initial-scale=1">
  <script src="viewport_helpers.js"></script>
</head>
<body>
  <script type="application/javascript">
    "use strict";

    add_task(async function change_content_attribute() {
      await SpecialPowers.pushPrefEnv(scaleRatio(1.0));

      let info = getViewportInfo(800, 480);
      // The second meta tag is the one we use.
      is(info.defaultZoom, 1, "initial zoom is 1");
      is(info.width, 800, "width should be 800");
      is(info.height, 480, "height should be 480");

      // Change the content of the first one.
      // eslint-disable-next-line no-undef
      first.setAttribute("content", "width=640");

      // Now the first one is prior to the second one.
      info = getViewportInfo(800, 480);
      fuzzeq(info.defaultZoom, 800/640, "initial scale is calculated based on width");
      is(info.minZoom, 0.25, "minimum scale defaults to the absolute minimum");
      is(info.maxZoom, 10, "maximum scale defaults to the absolute maximum");
      is(info.width, 640, "width is the default width");
      is(info.height, 480*640/800, "height is proportional to displayHeight");

      // Cleat the second content.
      // eslint-disable-next-line no-undef
      second.setAttribute("content", "");

      // The second one is prior to the first one, but the content is empty so
      // that we should behave as if there is no meta viewport tag.
      info = getViewportInfo(800, 480);
      is(info.defaultZoom, 0.25, "initial scale is clamped to the default mimumim scale");
      is(info.minZoom, 0.25, "minimum scale defaults to the absolute minimum");
      is(info.maxZoom, 10, "maximum scale defaults to the absolute maximum");
      is(info.width, 980, "width should be 980");
      is(info.height,588, "height is proportional to displayHeight");
    });
  </script>
</body>
</html>
