webpackをv3.10.0からv4.3.0に更新したら色々とこけたのでそのまとめです。 参考記事 (チュートリアル?) https://www.valentinog.com/blog/webpack-4-tutorial/ webpack-cliの追加 結果 The CLI moved into a separate package: webpack-cli. Please install 'webpack-cli' in addition to webpack itself to use the CLI. -> When using npm: npm install webpack-cli -D -> When using yarn: yarn add webpack-cli -D ✖ 「wds」: Invalid configuration object. Webpack has