Swap two nodes
The function below swaps two given nodes, nodeA and nodeB:
const swap = function (nodeA, nodeB) {
const parentA = nodeA.parentNode;
const siblingA = nodeA.nextSibling === nodeB ? nodeA : nodeA.nextSibling;
// Move `nodeA` to before the `nodeB`
nodeB.parentNode.insertBefore(nodeA, nodeB);
// Move `nodeB` to before the sibling of `nodeA`
parentA.insertBefore(nodeB, siblingA);
};