Recursive directory tree maker using only Node.js

dirtree.js

const fs = require('fs');
const path = require('path');

// Valid file extensions
const valideExts = ['.md', '.html'];

// Recursive directory parser
const treeMaker = (dir) => {
  return new Promise((resolve, reject) => {
    const children = {};

    fs.readdir(dir, async (err, list) => {
      if (err) reject();

      // Init children files container
      children.f = [];

      for (let child of list) {
        const childPath = `${dir}/${child}`;
        const isDir = fs.lstatSync(childPath).isDirectory();

        if (isDir) {
          // Parse sub-directory and record subtree
          const subtree = await treeMaker(childPath);
          children[child] = subtree;
        } else {
          // Validate and record files
          const fileExt = path.extname(child);
          if (valideExts.includes(fileExt)) children.f.push(child);
        }
      };

      resolve(children);
    });
  });
};

module.exports = async (rootPath) => {
  const tree = await treeMaker(rootPath);
  return tree;
};