webpack.config.js

// Provide a flag for turning on development mode
const isDevelopment = process.env.NODE_ENV === 'development';

// Plugins
const MiniCssExtractPlugin = require('mini-css-extract-plugin');

// Actual Webpack Config
module.exports = {
  entry: [
    './src/js/index.js',
  ],
  
  plugins: [
    new MiniCssExtractPlugin({
      filename: '[name].css',
      chunkFilename: '[id].css'
    })
  ],

  devtool: 'cheap-source-map',

  module: {
    rules: [
      {
        test: /\.module\.s(a|c)ss$/,
        loader: [
          isDevelopment ? 'style-loader' : MiniCssExtractPlugin.loader,
          {
            loader: 'css-loader',
            options: {
              modules: true,
              sourceMap: isDevelopment
            }
          },
          {
            loader: 'sass-loader',
            options: {
              sourceMap: isDevelopment
            }
          }
        ]
      },
      {
        test: /\.s(a|c)ss$/,
        exclude: /\.module.(s(a|c)ss)$/,
        loader: [
          isDevelopment ? 'style-loader' : MiniCssExtractPlugin.loader,
          'css-loader',
          {
            loader: 'sass-loader',
            options: {
              sourceMap: isDevelopment
            }
          }
        ]
      },
      {
        test: /\.ejs$/,
        use: [
          {
            loader: 'ejs-webpack-loader',
            options: {
              data: { title: "New Title", someVar: "hello world" },
              htmlmin: true
            }
          }
        ]
      }
    ]
  },

  resolve: {
    extensions: ['.js', '.jsx', '.scss']
  }
};