PhantomJSで動かすことを前提とするスクリプトファイルをwebpackでバンドルするための`webpack.config.js` (と簡略化した`package.json`) です。

package.json

{
  "babel": {
    "babelrc": false,
    "plugins": [
      "transform-es2015-modules-commonjs"
    ]
  },
  "eslintConfig": {
    "env": {
      "browser": true,
      "phantomjs": true
    },
    "extends": "airbnb-base"
  },
  "devDependencies": {
    "babel-core": "^6.23.1",
    "babel-loader": "^6.2.10",
    "babel-plugin-transform-async-to-generator": "^6.22.0",
    "babel-plugin-transform-es2015-arrow-functions": "^6.22.0",
    "babel-plugin-transform-es2015-block-scoping": "^6.23.0",
    "babel-plugin-transform-es2015-classes": "^6.23.0",
    "babel-plugin-transform-es2015-destructuring": "^6.23.0",
    "babel-plugin-transform-es2015-modules-commonjs": "^6.23.0",
    "babel-plugin-transform-es2015-parameters": "^6.23.0",
    "babel-plugin-transform-es2015-shorthand-properties": "^6.22.0",
    "babel-plugin-transform-es2015-spread": "^6.22.0",
    "babel-plugin-transform-es2015-template-literals": "^6.22.0",
    "babel-plugin-transform-regenerator": "^6.22.0",
    "babel-polyfill": "^6.23.0",
    "cross-env": "^3.1.4",
    "eslint": "^3.15.0",
    "eslint-config-airbnb-base": "^11.1.0",
    "eslint-plugin-import": "^2.2.0",
    "npm-run-all": "^4.0.1",
    "webpack": "^2.2.1"
  },
  "private": true,
  "scripts": {
    "build": "cross-env NODE_ENV=production webpack",
    "dev": "cross-env NODE_ENV=development webpack --watch",
    "lint": "eslint --ext js .",
    "prestart": "npm-run-all build",
    "start": "phantomjs build/crawler.js"
  }
}

webpack.config.babel.js

import path from 'path';

const babelrc = {
  plugins: [
    'transform-async-to-generator',
    'transform-es2015-arrow-functions',
    'transform-es2015-block-scoping',
    'transform-es2015-classes',
    'transform-es2015-destructuring',
    'transform-es2015-parameters',
    'transform-es2015-shorthand-properties',
    'transform-es2015-spread',
    'transform-es2015-template-literals',
    'transform-regenerator',
  ],
};

const crawlerConfig = {
  entry: {
    crawler: [
      'babel-polyfill',
      path.resolve(__dirname, 'src', 'crawler.js'),
    ],
  },
  externals: [
    {
      webpage: 'commonjs webpage',
    },
  ],
  module: {
    rules: [
      {
        exclude: path.resolve(__dirname, 'node_modules'),
        test: /\.js$/,
        use: {
          loader: 'babel-loader',
          options: Object.assign({
            babelrc: false,
          }, babelrc),
        },
      },
    ],
  },
  output: {
    filename: '[name].js',
    path: path.join(__dirname, 'build'),
  },
};

export default crawlerConfig;