webpack.common.js

const path = require('path')
const MiniCssExtractPlugin = require('mini-css-extract-plugin')
const { BundleAnalyzerPlugin } = require('webpack-bundle-analyzer')
module.exports = {
  entry: {
    entryA: path.resolve(__dirname, 'src/entryA.js'),
    entryB: path.resolve(__dirname, 'src/entryB.js')
  },
  output: {
    path: path.resolve(__dirname, 'dist'),
    filename: 'bundle.js',
    clean: true
  },
  module: {
    rules: [
      {
        test: /.js$/i,
        use: [
          'babel-loader'
        ]
      },
      {
        test: /\.(sa|sc|c)ss$/i,
        use: [
          MiniCssExtractPlugin.loader,
          'css-loader',
          'sass-loader'
        ]
      }
    ]
  },
  optimization: {
    usedExports: true,
    splitChunks: {
      chunks: 'all',
      name: 'chunk-vendors'
    }
  },
  plugins: [
    new BundleAnalyzerPlugin(),
    new MiniCssExtractPlugin()
  ]
}