LayoutTests/media/modern-media-controls/layout-node/children.html

<script src="../../../resources/js-test-pre.js"></script>
<script src="../../../../Source/WebCore/Modules/modern-media-controls/controls/scheduler.js" type="text/javascript"></script>
<script src="../../../../Source/WebCore/Modules/modern-media-controls/controls/layout-node.js" type="text/javascript"></script>
<script src="../resources/media-controls-utils.js" type="text/javascript"></script>
<script type="text/javascript">

description("Testing the <code>LayoutNode.children</code> property.");

window.jsTestIsAsync = true;

const node = new LayoutNode;

debug("Check default state");
shouldBeTrue("Array.isArray(node.children)");
shouldBeTrue("node.children.length === 0");

const a = new LayoutNode;
const b = new LayoutNode;
const c = new LayoutNode;

const children = [a, b, c];
node.children = children;

debug("");
debug("Set children to [a, b, c]");
shouldBeTrue("node.children.length === 3");
shouldBeTrue("node.children[0] === a");
shouldBeTrue("node.children[1] === b");
shouldBeTrue("node.children[2] === c");
shouldBeTrue("node.children !== children");

let numberOfFrames = 0;
scheduler.frameDidFire = function()
{
    debug("");
    debug("Layout was performed");

    switch (++numberOfFrames) {
    case 1:
        shouldBeTrue("node.element.childElementCount === 3");
        shouldBeTrue("node.element.firstElementChild === a.element");
        shouldBeTrue("node.element.firstElementChild.nextElementSibling === b.element");
        shouldBeTrue("node.element.lastElementChild === c.element");
        debug("");
        debug("Set children to be a copy of itself");
        node.children = Array.from(node.children);
        shouldBeFalse("node.children[0].needsLayout");
        shouldBeFalse("node.children[1].needsLayout");
        shouldBeFalse("node.children[2].needsLayout");
        debug("");
        debug("Set children to [b, a]");
        node.children = [b, a];
        shouldBeTrue("node.children.length === 2");
        shouldBeTrue("node.children[0] === b");
        shouldBeTrue("node.children[1] === a");
        break;
    case 2:
        shouldBeTrue("node.element.childElementCount === 2");
        shouldBeTrue("node.element.firstElementChild === b.element");
        shouldBeTrue("node.element.lastElementChild === a.element");
        debug("");
        debug("Set children to []");
        node.children = [];
        shouldBeTrue("node.children.length === 0");
        break;
    case 3:
        shouldBeTrue("node.element.childElementCount === 0");
        finishMediaControlsTest();
        break;
    }
};

</script>
<script src="../../../resources/js-test-post.js"></script>