fs-of-type/index.js

'use strict';
const fs = require('fs');
const path = require('path');
const async = require('async');
const pathExists = require('path-exists');
const untildify = require('untildify');

const home = process.env[process.platform === 'win32' ? 'USERPROFILE' : 'HOME'];
const pascal = str => str[0].toUpperCase() + str.slice(1);
const parseHome = str => str.split(path.sep).slice(0,3).join(path.sep) === home ? str : path.join(home, str);

module.exports = (ptc, type, cb) => {
  ptc = parseHome(untildify(ptc));
  type = Array.isArray(type) ? type.map(pascal) : pascal(type);

  pathExists(ptc)
    .then(result => {
      if (!result) return cb(new Error(`${ptc} is not a valid path\n`));

      async.waterfall([
        async.apply(read, ptc),
        filter
      ], (err, ofType) => {
        if (err) return cb(err);

        cb(null, ofType);
      })
    })

  function read(pathTo, cb) {
    fs.readdir(pathTo, (err, contents) => {
      if (err) return cb(err);

      cb(null, contents);
    })
  }

  function filter(contents, cb) {
    async.filter(contents, (item, cb) => {
      fs.stat(path.join(ptc, item), (err, stats) => {
        if (err) return cb(err);

        cb(null, Array.isArray(type) ? type.some(t => stats['is' + t]()) : stats['is' + type]());
      })
    }, (err, filtered) => {
      if (err) return cb(err);

      cb(null, filtered);
    })
  }
}