image-full-viewport.html | Explore in Territory

<!DOCTYPE HTML>
<meta charset=utf-8>
<title>Largest Contentful Paint: size when image overflows</title>
<!-- In this test, an image with an intrinsic size of 100 x 50 is added, but
  scaled up in order to overflow the viewport. It should not be reported. -->
<body>
<style>
body {
  margin: 0px;
}
</style>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/largest-contentful-paint-helpers.js"></script>
<script>
  const viewportWidth = document.documentElement.clientWidth;
  const viewportHeight = document.documentElement.clientHeight;
  setup({"hide_test_state": true});
  async_test(function (t) {
    assert_implements(window.LargestContentfulPaint, "LargestContentfulPaint is not implemented");
    const beforeLoad = performance.now();
    new PerformanceObserver(
      t.step_func_done(function(entryList) {
        assert_equals(entryList.getEntries().length, 1, 'Should have received only one entry!');
        const entry = entryList.getEntries()[0];
        if (entry.url)
          assert_unreached('Should not have received an image entry!');
      })
    ).observe({type: 'largest-contentful-paint', buffered: true});
    // Add an image, setting width and height equal to viewport.
    img = document.createElement('img');
    img.src = '/images/lcp-100x50.png';
    img.id = 'image_id';
    img.width = viewportWidth * 2;
    img.height = viewportHeight * 2;
    img.onload = () => {
      const p = document.createElement('p');
      p.innerHTML = 'a';
      p.style = 'position: absolute; top: 10px; left: 10px;';
      document.body.appendChild(p);
    }
    document.body.appendChild(img);
  }, 'The intersectionRect of an img element overflowing is computed correctly');
</script>
</body>
chromium/third_party/blink/web_tests/external/wpt/largest-contentful-paint/image-full-viewport.html
