index.js

/**
 * Escape special characters in the given string of html.
 *
 * @param  {String} html
 * @return {String}
 */
module.exports = {
  escape: function(html) {
    return String(html)
      .replace(/&/g, '&')
      .replace(/"/g, '"')
      .replace(/\'/g, ''')
      .replace(/</g, '&lt;')
      .replace(/>/g, '&gt;');
  },

  /**
   * Unescape special characters in the given string of html.
   *
   * @param  {String} html
   * @return {String}
   */
  unescape: function(html) {
    return String(html)
      .replace(/&amp;/g, '&')
      .replace(/&quot;/g, '"')
      .replace(/&#39;/g, '\'')
      .replace(/&lt;/g, '<')
      .replace(/&gt;/g, '>');
  }
};

package.json

{
  "name": "test-package",
  "version": "1.0.0",
  "description": "Test package",
  "main": "index.js",
  "scripts": {
    "dev": "webpack --watch --progress --colors --config webpack.dev.config.js",
    "build": "webpack && webpack --config webpack.dev.config.js",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "devDependencies": {
    "babel-core": "^6.4.5",
    "babel-eslint": "^4.1.6",
    "babel-loader": "^6.2.1",
    "babel-preset-es2015": "^6.3.13",
    "eslint": "^1.10.3",
    "eslint-loader": "^1.2.1",
    "webpack": "^1.12.12",
    "escope": "3.3.0"
  }
}

webpack.config.js

var webpack = require('webpack');
var uglifyJsPlugin = webpack.optimize.UglifyJsPlugin;

module.exports = {
  debug: true,
  entry: './index.js',
  output: {
    path: '.',
    filename: "test-package.min.js",
    library: "test-package",
    libraryTarget: "umd"
  },
  module: {
    preLoaders: [
      {
        test: /\.js$/,
        loader: 'eslint-loader',
        exclude: /node_modules/
      }
    ],
    loaders: [
      {
        test: /\.js$/,
        loader: 'babel-loader',
        exclude: /node_modules/,
        query: {
          presets: ['es2015']
        }
      }
    ]
  },
  plugins: [
    new uglifyJsPlugin({
      compress: {
        warnings: false
      }
    })
  ],
  eslint: {
    configFile: '.eslintrc'
  }
};

webpack.dev.config.js

var webpack = require('webpack');

module.exports = {
  debug: true,
  entry: './index.js',
  output: {
    path: '.',
    filename: "test-package.js",
    library: "test-package",
    libraryTarget: "umd"
  },
  module: {
    preLoaders: [
      {
        test: /\.js$/,
        loader: 'eslint-loader',
        exclude: /node_modules/
      }
    ],
    loaders: [
      {
        test: /\.js$/,
        loader: 'babel-loader',
        exclude: /node_modules/,
        query: {
          presets: ['es2015']
        }
      }
    ]
  },
  eslint: {
    configFile: '.eslintrc'
  }
};