Find common parent element of n nodes

find-common-parent.js

/**
 * Find common parent node
 */
export function findCommonParent(...nodes) {
    let nodeParents = nodes.map(node => findParents(node)),
        firstNodeParents = nodeParents[0],
        topParent = firstNodeParents[0];

    if (nodeParents.some(parents => parents.indexOf(topParent) !== 0)) {
        // no common parent
        return null;
    }

    for (let i = firstNodeParents.length - 1; i >= 0; i -= 1) {
        if (nodeParents.every(parents => parents.indexOf(firstNodeParents[i]) >= 0)) {
            return firstNodeParents[i];
        }
    }
    return null;
}

/**
 * Find all node parents
 * Taken from: http://stackoverflow.com/a/5350888
 */
export function findParents(node) {
    var nodes = [node];
    for (; node; node = node.parentNode) {
        nodes.unshift(node);
    }
    return nodes;
}