index.js

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

const loader = (filePath, name, args) => {
  const func = () => (name ? module.require(filePath + name) : module.require(filePath));

  return (args && func.apply(func, args)) || func();
};

/**
 * an simply way the load files in dir
 * @param {Object} options - config
 * @param {Object} [options.patcher={}] - the obj need to load files module to
 * @param {String} [options.path='./'] - it will join with dirName is relative path
 * @param {String} [options.dirname=process.env.PWD or __dirname] - root of dirPath
 * @param {Mixed} [options.args=[]] - args would pass to those files module
 **/
const loadDir = (options) => {
  const opts = _.defaults(options || {}, {
    patcher: {},
    path: './',
    dirPath: null,
    dirname: process.env.PWD || __dirname,
    args: [],
    includeDir: false,
  });

  // Compatible with older versions
  const dirOrig = opts.dirPath || opts.path;
  // once dirOrig have the same prefix of opts.dirname
  // should not join cuz dirOrig is absolute path
  const dirPath = dirOrig.startsWith(opts.dirname) ? dirOrig : path.join(opts.dirname, dirOrig);

  fs.readdirSync(dirPath).forEach((filename) => {
    if (!/\.js$/.test(filename) && !opts.includeDir) { return; }

    const name = path.basename(filename, '.js');
    const load = loader.bind(null, `${dirPath}/`, name, opts.args);

    Object.defineProperty(opts.patcher, name, { get: load });
  });

  return opts.patcher;
};

module.exports = loadDir;