webpack.config.js

const buildValidations = require("./build-utils/build-validations");
const commonConfig = require("./build-utils/webpack.common");

const webpackMerge = require("webpack-merge");

const addons = (/* string | string[] */ addonsArg) => {
  let addons = [...[addonsArg]] // Normalize array of addons (flatten)
    .filter(Boolean); // If addons is undefined, filter it out

  return addons.map((addonName) =>
    require(`./build-utils/addons/webpack.${addonName}.js`)
  );
};

module.exports = (env) => {
  if (!env) {
    throw new Error(buildValidations.ERR_NO_ENV_FLAG);
  }

  const envConfig = require(`./build-utils/webpack.${env.env}.js`);
  const mergedConfig = webpackMerge(
    commonConfig,
    envConfig,
    ...addons(env.addons)
  );

  return mergedConfig;
};