Method moveBefore

src/main/java/org/htmlunit/html/DomNode.java:1340–1378

Add a DOM node as a child to this node before the referenced node. If the referenced node is null, append to the end. @param movedDomNode the node to move @param referenceDomNode the node to move before @throws DOMException in case of problems

(final DomNode movedDomNode, final DomNode referenceDomNode)

     * @throws DOMException in case of problems
     */
    public void moveBefore(final DomNode movedDomNode, final DomNode referenceDomNode) {
        if (movedDomNode == referenceDomNode) {
            return;
        }

        if (movedDomNode instanceof DomDocumentFragment fragment) {
            for (final DomNode child : fragment.getChildren()) {
                moveBefore(child, referenceDomNode);
            }
            return;
        }

        // If moving to the same position (node is already right before referenceNode), no operation needed
        if (referenceDomNode != null && movedDomNode.getNextSibling() == referenceDomNode) {
            return;
        }

        if (movedDomNode.isAncestorOf(this)) {
            throw new DOMException(DOMException.HIERARCHY_REQUEST_ERR,
                    "The new child element contains the parent.");
        }

        if (referenceDomNode != null && !this.isAncestorOf(referenceDomNode)) {
            throw new DOMException(DOMException.NOT_FOUND_ERR,
                    "The node before which the new node is to be inserted is not a child of this node.");
        }

        if (referenceDomNode != null && referenceDomNode.isAttachedToPage() && !movedDomNode.isAttachedToPage()) {
            throw new DOMException(DOMException.HIERARCHY_REQUEST_ERR,
                    "State-preserving atomic move cannot be performed on nodes participating in an invalid hierarchy.");
        }

        if (referenceDomNode == null) {
            appendChild(movedDomNode);
            return;
        }

        referenceDomNode.moveBefore(movedDomNode);
    }

    /**
     * Inserts the specified node as a new child node before this node into the child relationship this node is a