index.js

var fs = require('fs');

module.exports = function () {
  return fs
    .readdirSync(__dirname)
    .filter(function (file) { return /\.json$/.test(file); })
    .reduce(function (config, file) {
      return extend(config, require(__dirname + '/' + file));
    }, {});
};

function extend (origin, add) {
  if (!add || typeof add !== 'object') return origin;

  var keys = Object.keys(add);
  var i = keys.length;
  while (i--) {
    origin[keys[i]] = add[keys[i]];
  }
  return origin;
}