memEx/assets/webpack.config.js

const path = require('path')
const glob = require('glob')
const MiniCssExtractPlugin = require('mini-css-extract-plugin')
const TerserPlugin = require('terser-webpack-plugin')
const CssMinimizerPlugin = require('css-minimizer-webpack-plugin')
const CopyWebpackPlugin = require('copy-webpack-plugin')

module.exports = (env, options) => {
  const devMode = options.mode !== 'production'

  return {
    optimization: {
      minimizer: [
        new TerserPlugin({ parallel: true, extractComments: true }),
        new CssMinimizerPlugin({})
      ]
    },
    entry: {
      app: glob.sync('./vendor/**/*.js').concat(['./js/app.js'])
    },
    output: {
      filename: '[name].js',
      path: path.resolve(__dirname, '../priv/static/js'),
      publicPath: '/js/'
    },
    devtool: devMode ? 'eval-cheap-module-source-map' : undefined,
    module: {
      rules: [
        {
          test: /\.js$/,
          exclude: /node_modules/,
          use: {
            loader: 'babel-loader'
          }
        },
        {
          test: /\.s?css$/,
          use: [
            MiniCssExtractPlugin.loader,
            'css-loader',
            'postcss-loader',
            'sass-loader'
          ]
        },
        {
          test: /\.(woff(2)?|ttf|eot|svg|otf)(\?v=[0-9]\.[0-9]\.[0-9])?$/,
          type: 'asset/resource',
          generator: { filename: 'fonts/[name][ext]' }
        }
      ]
    },
    plugins: [
      new MiniCssExtractPlugin({ filename: '../css/app.css' }),
      new CopyWebpackPlugin({ patterns: [{ from: 'static/', to: '../' }] })
    ]
  }
}