ASTを再帰的に探索してnodeDepthをつけるremark plugin

remark-node-depth.js

/**
 * 再帰的にchildren nodeを探索してnodeにnodeDepthを付ける
 *
 * @param {Array} children - node chldren
 * @param {Number} depth - childrenのnodeDepth数
 */
function attachNodeDepth(children, depth) {
  for (const node of children) {
    node.nodeDepth = depth;
    if (node.children) attachNodeDepth(node.children, depth + 1);
  }
}

function transformer(node) {
  const depth = 0;
  if (node.type === 'root') node.nodeDepth = depth;
  attachNodeDepth(node.children, depth + 1);
}

module.exports = function attacher() {
  return transformer;
};