observe-svg-background-image.html | Explore in Territory

<!DOCTYPE HTML>
<meta charset=utf-8>
<title>Largest Contentful Paint: observe image.</title>
<style>
  #target {
    background-image: url('/images/green.svg');
    width: 100px;
    height: 50px;
  }
</style>
<body>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/largest-contentful-paint-helpers.js"></script>
<script>
  async_test(function (t) {
    assert_implements(window.LargestContentfulPaint, "LargestContentfulPaint is not implemented");
    const beforeLoad = performance.now();
    const observer = new PerformanceObserver(
      t.step_func_done(function(entryList) {
        assert_equals(entryList.getEntries().length, 1);
        const entry = entryList.getEntries()[0];
        let url = window.location.origin + '/images/green.svg';
        // green.svg is 100 by 50
        const size = 100 * 50;
        checkImage(entry, url, 'target', size, beforeLoad);
      })
    );
    observer.observe({type: 'largest-contentful-paint', buffered: true});
    t.step_timeout(() => {
      assert_unreached("The image should have triggered an LCP entry.");
      t.done();
    }, 1000);
  }, 'Same-origin SVG background image is observable.');
</script>

<div id="target" width="100" height="50"></div>
</body>

chromium/third_party/blink/web_tests/external/wpt/largest-contentful-paint/observe-svg-background-image.html