webpack.config.js

var vue = require('vue-loader')
var webpack = require("webpack")
var ExtractTextPlugin = require("extract-text-webpack-plugin")

var cssLoader = ExtractTextPlugin.extract("style-loader", "css-loader")

module.exports = {
  entry: {
    app: './src/app.js'
  },
  output: {
    path: './build',
    publicPath: '/build/',
    filename: 'bundle.js'
  },
  module: {
    loaders: [
      {
        test: /\.vue$/,
        loader: 'vue'
      },
      {
        test: /\.js$/,
        // excluding some local linked packages.
        // for normal use cases only node_modules is needed.
        exclude: /node_modules|vue\/src|vue-router\/|vue-loader\/|vue-hot-reload-api\//,
        loader: 'babel'
      },
      { test: /\.css$/, loader: cssLoader }
    ]
  },
  // vue: {
  //   loaders: {
  //     css: ExtractTextPlugin.extract("css"),
  //     stylus: ExtractTextPlugin.extract("css!stylus")
  //   }
  // },
  devtool: "#source-map",
  babel: {
    presets: ['es2015'],
    plugins: ['transform-runtime']
  }
}

if (process.env.NODE_ENV === 'production') {
  
  delete module.exports.devtool
  module.exports.plugins = [
    new webpack.DefinePlugin({
      'process.env': {
        NODE_ENV: '"production"'
      }
    }),
    new webpack.optimize.UglifyJsPlugin({
      compress: {
        warnings: false
      }
    }),
    new webpack.optimize.OccurenceOrderPlugin()
    // new ExtractTextPlugin("build.css")
  ]
} else {
  // module.exports.plugins = [
  //   new ExtractTextPlugin("build.css")
  // ]
  // module.exports.devtool = '#source-map'
}