creare-react-app facebookが提供しているCLIツール。Reactは、開発環境を作るのがそれなりに大変ですが、このCLIツールを使うと雛形、テスト、devサーバ、ビルド、ESLintまで全部用意してくれます。 script毎の変数 create-react-appでプロジェクトを作成するとpackage.jsonには、予めスクリプトが書かれています "scripts": { "start": "react-scripts-ts start ", "build": "react-scripts-ts build", "test": "react-scripts-ts test --env=jsdom --watchAll", "eject": "react-scripts-ts eject" }, この中で、start、build、testは実行時に、process.e
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