preload/dynamic-adding-preload-imagesrcset.html

<!DOCTYPE html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/preload/resources/preload_helper.js"></script>
<script>
    var t = async_test('Makes sure that a dynamically added preload with imagesrcset works');
</script>
<body>
<script>
    t.step(function() {
        verifyPreloadAndRTSupport();
        var expectation = new Array(4).fill(0);
        if (window.devicePixelRatio < 1.5) {
          expectation[2] = 1;
        } else if (window.devicePixelRatio >= 1.5) {
          expectation[3] = 1;
        }
        var link = document.createElement("link");
        link.as = "image";
        link.rel = "preload";
        link.href = "resources/square.png?default";
        link.imageSrcset = "resources/square.png?200 200w, resources/square.png?400 400w, resources/square.png?800 800w";
        link.imageSizes = "400px";
        link.onload = t.step_func(function() {
            t.step_timeout(function() {
                verifyNumberOfResourceTimingEntries("resources/square.png?default", expectation[0]);
                verifyNumberOfResourceTimingEntries("resources/square.png?200", expectation[1]);
                verifyNumberOfResourceTimingEntries("resources/square.png?400", expectation[2]);
                verifyNumberOfResourceTimingEntries("resources/square.png?800", expectation[3]);
                t.done();
            }, 0);
        });
        document.body.appendChild(link);
    });
</script>
</body>