webpack.config.js

const path = require('path')
const webpack = require('webpack')
module.exports = {
  devtool: 'source-map',
  entry: './src/app.js',
  output: {
    path: path.resolve(__dirname, './build'),
    filename: 'bundle.js'
  },
  module: {
    rules: [{
      test: /\.js$/,
      exclude: /node_modules/,
      loader: 'babel-loader',
      query: {
        plugins: ['transform-runtime'],
        presets: ['es2015', 'react', 'stage-2']
      }
    }, {
      test: /\.css$/,
      exclude: /node_modules/,
      loader: 'style-loader!css-loader'
    }, {
      test: /\.styl$/,
      exclude: /node_modules/,
      loader: 'style-loader!css-loader!stylus-loader'
    }]
  }
}
if (process.env.NODE_ENV === 'production') {
  module.exports.devtool = '#source-map'
  module.exports.plugins = (module.exports.plugins || []).concat([
    new webpack.optimize.UglifyJsPlugin({
      sourceMap: true,
      compress: {
        warnings: false
      }
    }),
    new webpack.LoaderOptionsPlugin({
      minimize: true
    })
  ])
} else {
  module.exports.plugins = (module.exports.plugins || []).concat([
    new webpack.HotModuleReplacementPlugin()
  ])
  module.exports.devServer = {
    port: 7777,
    host: 'localhost',
    hot: true, // 告诉 dev-server 我们在使用 HMR
    contentBase: __dirname,
    inline: true,
    historyApiFallback: true
  }
}