Sigi framework CRA example Customize babel config in CRA project 1. Install dependencies and babel plugins yarn install @babel/plugin-proposal-decorators babel-plugin-transform-typescript-metadata customize-cra react-app-rewired --dev 2. Change scripts in package.json /* package.json */ "scripts": { - "start": "react-scripts start", + "start": "react-app-rewired start", - "build": "react-scripts build", + "build": "react-app-rewired build", - "test": "react-scripts test", + "test": "react-app-rewired test", "eject": "react-scripts eject" } 3. Add config-overrides.js and .babelrc const { override, useBabelRc } = require('customize-cra'); module.exports = override( useBabelRc() ); { "plugins": [ "babel-plugin-transform-typescript-metadata", [ "@babel/plugin-proposal-decorators", { "legacy": true } ] ] }