config.js

var path = require('path');
var webpack = require('webpack');

module.exports = {
  entry: {
    index: ['./app/core'],
  },
  output: {
    publicPath: '/',
    filename: 'bundle.js',
  },
  externals: {
    'firebase': 'firebase',
    'lodash': '_',
    'jsondiffpatch': 'jsondiffpatch',
  },
  resolve: {
    extensions: ['.ts', '.js'],
    modules: [path.resolve('./app'), 'node_modules']
  },
  module: {
    loaders: [{
      test: /\.ts$/,
      loader: 'ts-loader',
      options: {
        transpileOnly: true
      }
    }],
  },
  plugins: [
    new webpack.EnvironmentPlugin(['NODE_ENV'])
  ],
  devtool: 'cheap-module-eval-source-map',
  devServer: {
    host: '0.0.0.0',
    contentBase: 'app/core',
    historyApiFallback: true,
    hot: true,
    inline: true,
  }
};