mkdirp.js

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

const promisify = fn => (...args) =>
  new Promise((resolve, reject) =>
    fn(...args, (err, res) => err === null ? resolve(res) : reject(err))
  );

const mkdir = promisify(fs.mkdir);
const stat = promisify(fs.stat);

const mkdirp = (dir, opts) =>
  mkdir(dir, opts)
    .then(() => dir)
    .catch(err =>
      err.code == "ENOENT"
        ? mkdirp(path.dirname(dir), opts).then(() => mkdirp(dir, opts))
        : stat(dir).then(() => dir)
    );

module.exports = mkdirp;