aureooms/js-skip-list

import assert from 'assert';

const deleteFromTopMost = (node) => {
    assert(node !== null);
    assert(node.up === null); // Node is from top-most level
    do {
        assert(node.left !== null); // Node is not sentinel
        node.left.right = node.right;
        if (node.right !== null) node.right.left = node.left;
        node = node.down;
    } while (node !== null);
};

export default deleteFromTopMost;