"Note: This command is considered for advanced use cases only. Unless you are experiencing issues with the amount of files that are installed as part of node_modules it is not recommended to use this command. It uses a heuristic to identify files that may not be needed from a distributed package and may not be entirely safe." あーね
yarn clean | Yarn https://yarnpkg.com/en/docs/cli/clean/
@Clworld 思った思った。既に使われていないパッケージを削除するぐらいかと思った。まさか中身もいい感じに掃除するやつだとは...。