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({})]
  }
});