webpack.config.js

const path = require('path');
const VueLoaderPlugin = require('vue-loader/lib/plugin')
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
require("babel-polyfill");

module.exports = {
  entry: ["babel-polyfill", "./server.js"],
  entry: {
    app: './src/app/main.js'
  },
  output: {
    path: path.join(__dirname, 'src/public/js'),
    filename: 'bundle.js',
    publicPath: '/'
  },
  resolve: {
    alias: {
      vue: 'vue/dist/vue.js'
    }
  },
  module: {
    rules: [
      {
        test: /\.js$/,
        loader: 'babel-loader',
        exclude: /node_modules/,
        query: {
          presets: ['@babel/preset-env']
        }
      },
      {
        test: /\.vue$/,
        exclude: /node_modules/,
        use: {
          loader: 'vue-loader'
        }
      },
      {
        test: /\.css$/,
        use: [
          MiniCssExtractPlugin.loader, // instead of style-loader
          'css-loader'
        ]
      }
    ]
  },
  devServer: {
    port: 3000
  },
  plugins: [
    new VueLoaderPlugin(),
    new MiniCssExtractPlugin()
  ]
};