ladybird/Tests/LibWeb/Text/input/collapse-selection-inside-shadow-root.html

<script src="include.js"></script>
<button id="button1"></button>
<div id="root"></div>
<script>
    function printSelectionNodes(selection) {
        if (selection.anchorNode) {
            println(`${selection.anchorNode.id}`);
        } else {
            println(`${selection.anchorNode}`);
        }
        if (selection.focusNode) {
            println(`${selection.focusNode.id}`);
        } else {
            println(`${selection.focusNode}`);
        }
    }

    test(() => {
        printSelectionNodes(document.getSelection());

        const button1 = document.querySelector("#button1");
        document.getSelection().collapse(button1);

        printSelectionNodes(document.getSelection());

        const rootElement = document.getElementById("root");
        const shadowRoot = rootElement.attachShadow({ mode: "open" });
        const button2 = document.createElement("button");
        button2.id = "button2";
        shadowRoot.appendChild(button2);
        document.getSelection().collapse(button2);

        printSelectionNodes(document.getSelection());
    });
</script>