sphinx_rtd_theme/webpack.prod.js

const merge = require('webpack-merge');
const OptimizeCssAssetsPlugin = require('optimize-css-assets-webpack-plugin');
const TerserPlugin = require('terser-webpack-plugin');
const common = require('./webpack.common.js');

module.exports = merge(common, {
  mode: 'production',
  optimization: {
    minimizer: [new TerserPlugin(), new OptimizeCssAssetsPlugin({})],
  },
});