SyntaxError: Unexpected token: name (path) [./cfg/base.js:2,0] when running dist

[Mxxim]

npm run dist, it happens error:

ERROR in app.js from UglifyJs
SyntaxError: Unexpected token: name (path) [./cfg/base.js:2,0]

The line happens error:

let path = require('path');

I think UglifyJs cant parse let, so it throws SyntaxError. And I know UglifyJs can't parse ES6, but I have used babel to transform ES6 into ES5,

my package.json:

  "devDependencies": {
    "axios": "^0.15.3",
    "babel-core": "^6.0.0",
    "babel-eslint": "^6.0.0",
    "babel-loader": "^6.0.0",
    "babel-polyfill": "^6.3.14",
    "babel-preset-es2015": "^6.0.15",
    "babel-preset-react": "^6.0.15",
    "babel-preset-stage-0": "^6.5.0",
    "bower-webpack-plugin": "^0.1.9",
    "chai": "^3.2.0",
    "classnames": "^2.2.5",
    "copyfiles": "^1.0.0",
    "css-loader": "^0.23.0",
    "eslint": "^3.0.0",
    "eslint-loader": "^1.0.0",
    "eslint-plugin-react": "^6.0.0",
    "file-loader": "^0.9.0",
    "glob": "^7.0.0",
    "isparta-instrumenter-loader": "^1.0.0",
    "jquery": "^3.2.1",
    "karma": "^1.0.0",
    "karma-chai": "^0.1.0",
    "karma-coverage": "^1.0.0",
    "karma-mocha": "^1.0.0",
    "karma-mocha-reporter": "^2.0.0",
    "karma-phantomjs-launcher": "^1.0.0",
    "karma-sourcemap-loader": "^0.3.5",
    "karma-webpack": "^1.7.0",
    "minimist": "^1.2.0",
    "mocha": "^3.0.0",
    "node-sass": "^4.5.1",
    "null-loader": "^0.1.1",
    "open": "0.0.5",
    "phantomjs-prebuilt": "^2.0.0",
    "postcss-loader": "^1.3.3",
    "react-addons-test-utils": "^15.0.0",
    "react-alert": "^1.0.14",
    "react-bootstrap": "^0.30.8",
    "react-bootstrap-table": "^3.1.6",
    "react-hot-loader": "^1.2.9",
    "react-modal": "^1.7.3",
    "react-s-alert": "^1.2.2",
    "rimraf": "^2.4.3",
    "rodal": "^1.4.1",
    "sass-loader": "^5.0.1",
    "style-loader": "^0.13.0",
    "url-loader": "^0.5.6",
    "webpack": "^1.12.0",
    "webpack-dev-server": "^1.12.0"
  },
  "dependencies": {
    "core-js": "^2.0.0",
    "normalize.css": "^4.0.0",
    "react": "^15.0.0",
    "react-dom": "^15.0.0",
    "react-redux": "^5.0.3",
    "react-router": "^4.0.0",
    "react-router-dom": "^4.0.0",
    "redux": "^3.6.0",
    "redux-thunk": "^2.2.0"
  }

my .babelrc:

{
  "presets": [
    "es2015",
    "stage-0",
    "react"
  ]
}

my default.js:

/**
 * Function that returns default values.
 * Used because Object.assign does a shallow instead of a deep copy.
 * Using [].push will add to the base array, so a require will alter
 * the base array output.
 */
'use strict';

const path = require('path');
const srcPath = path.join(__dirname, '/../src');
const dfltPort = 8000;

/**
 * Get the default modules object for webpack
 * @return {Object}
 */
function getDefaultModules() {
  return {
    preLoaders: [
      {
        test: /\.(js|jsx)$/,
        include: srcPath,
        loader: 'eslint-loader'
      }
    ],
    loaders: [
      {
        test: /\.css$/,
        loader: 'style-loader!css-loader!postcss-loader'
      },
      {
        test: /\.sass/,
        loader: 'style-loader!css-loader!postcss-loader!sass-loader?outputStyle=expanded&indentedSyn'
      },
      {
        test: /\.scss/,
        loader: 'style-loader!css-loader!postcss-loader!sass-loader?outputStyle=expanded'
      },
      {
        test: /\.less/,
        loader: 'style-loader!css-loader!postcss-loader!less-loader'
      },
      {
        test: /\.styl/,
        loader: 'style-loader!css-loader!postcss-loader!stylus-loader'
      },
      {
        test: /\.(png|jpg|gif|woff|woff2|eot|ttf|svg)$/,
        loader: 'url-loader?limit=8192' 
      },
      {
        test: /\.(mp4|mp3|ogg|svg)$/,
        loader: 'file-loader'
      }
    ]
  };
}

module.exports = {
  srcPath: srcPath,
  publicPath: '/assets/',
  port: dfltPort,
  getDefaultModules: getDefaultModules
};

Node version: v6.9.1
NPM version: v3.10.8

Can you tell me how to fix it please? Thanks in advance.😊