webpack.config.js

const DashboardPlugin = require('webpack-dashboard/plugin');
const OptimizeCSSAssets = require('optimize-css-assets-webpack-plugin');

const devMode = process.env.NODE_ENV === 'development';

const path = require('path');
const { CleanWebpackPlugin } = require('clean-webpack-plugin');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');

let config = {
  entry: './src/index.js',
  output: {
    filename: 'bundle.js',
    path: path.resolve(__dirname, 'public'),
  },
  plugins: [
    new CleanWebpackPlugin({ cleanAfterEveryBuildPatterns: ['public'] }),
    new DashboardPlugin(),
    new HtmlWebpackPlugin({
      template: './src/index.html',
      minify: false
    }),
    new MiniCssExtractPlugin({
      filename: 'styles.css'
    })
  ],
  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: /node_modules/,
        loader: 'babel-loader'
      }, {
        test: /\.(sa|sc|c)ss$/,
        use: [
          devMode ? 'style-loader' : MiniCssExtractPlugin.loader,
          'css-loader',
          'sass-loader'
        ]
      }, {
        test: /\.(jpe?g|png|gif|svg)$/i,
        loaders: [{
          loader: 'file-loader',
          options: {
            name: 'assets/images/[name].[ext]'
          }
        }]
      }
    ]
  },
  devServer: {
    contentBase: path.resolve(__dirname, 'public'),
    open: true
  }
};
module.exports = config;

if (process.env.NODE_ENV === 'production') {
  module.exports.plugins.push(
    new OptimizeCSSAssets() // call the css optimizer (minification)
  );
}