observe-random-namespace.html | Explore in Territory

<!DOCTYPE HTML>
<meta charset=utf-8>
<title>Largest Contentful Paint: observe element created in a random namespace</title>
<body>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/largest-contentful-paint-helpers.js"></script>
<style>
  div {
    display: block;
  }
</style>
<script>
  async_test(function (t) {
    assert_implements(window.LargestContentfulPaint, "LargestContentfulPaint is not implemented");
    let beforeRender;
    const observer = new PerformanceObserver(
      t.step_func_done(function(entryList) {
        assert_equals(entryList.getEntries().length, 1);
        const entry = entryList.getEntries()[0];
        assert_equals(entry.entryType, 'largest-contentful-paint');
        assert_greater_than_equal(entry.renderTime, beforeRender);
        assert_greater_than_equal(performance.now(), entry.renderTime);
        assert_approx_equals(entry.startTime, entry.renderTime, 0.001,
          'startTime should be equal to renderTime to the precision of 1 millisecond.');
        assert_equals(entry.duration, 0);
        // Some lower bound: height of at least 12 px.
        // Width of at least 100 px.
        assert_greater_than(entry.size, 1200);
        assert_equals(entry.loadTime, 0);
        assert_equals(entry.url, '');
        assert_equals(entry.id, 'my_text');
        assert_equals(entry.element, document.getElementById("my_text"));
      })
    );
    observer.observe({type: 'largest-contentful-paint', buffered: true});

    const div = document.createElementNS("random", "div");
    div.innerHTML = "This is important text! :)";
    div.id = "my_text";
    beforeRender = performance.now();
    document.body.appendChild(div);
  }, 'Element created with different namespace is observable');
</script>
</body>
chromium/third_party/blink/web_tests/external/wpt/largest-contentful-paint/observe-random-namespace.html
