title: Trying to configure Babel in a monorepo project - 'classProperties' isn't currently enabled. How to set up Babel in a monorepo project?
body: <p>I have a monorepo that is set according to this tutorial: <a href="https://www.youtube.com/watch?v=k8rc9hdJ0Lc&amp;list=PLN3n1USn4xll9wq0rw0ECrO0j2PFzuXtn&amp;index=4" rel="nofollow noreferrer">tutorial</a>.</p>
  
  <p>This project is composed by a main folder (series4) that holds three packages, which are focused on web, mobile applications and common code - they are named web, app and common folders respectively.  </p>
  
  <p>Summarizing ... these folders are:</p>
  
  <pre><code>/series4/packages/web
  /series4/packages/common
  /series4/packages/app
  </code></pre>
  
  <p>I am trying to use the Modal module, however I get this error: </p>
  
  <blockquote>
    <p>SyntaxError: series4/node_modules/react-native-modal/src/index.js:
    Support for the experimental syntax 'classProperties' isn't currently
    enabled (25:20)</p>
  </blockquote>
  
  <p>I have read the documentation that is here: <a href="https://babeljs.io/docs/en/config-files#6x-vs-7x-babelrc-loading" rel="nofollow noreferrer">Babel</a>.</p>
  
  <p>However I was not able to solve this error. </p>
  
  <p>The package.json that is in "series4" directory is:</p>
  
  <pre><code>{
    "name": "@wow/common",
    "version": "1.0.0",
    "description": "",
    "main": "dist/index.js",
    "scripts": {
      "build": "rimraf dist &amp;&amp; tsc",
      "watch": "tsc --watch"
    },
    "keywords": [],
    "author": "",
    "license": "ISC",
    "dependencies": {
      "react": "16.8.2",
      "react-native": "0.59.0-rc.1",
      "react-native-elements": "^1.1.0",
      "react-native-image-slider-box": "^1.0.5",
      "react-native-snap-carousel": "^3.8.0"
    },
    "devDependencies": {
      "@babel/plugin-proposal-class-properties": "^7.5.5",
      "@types/react-native": "0.57.36",
      "rimraf": "^2.6.3",
      "typescript": "3.3.3"
    }
  }
  </code></pre>
  
  <p>The babel.config.js file (it is in series4 directory) is:</p>
  
  <pre><code>module.exports =  {
      presets: [
          "@babel/preset-env",
          "@babel/preset-react"
      ],
      plugins: [
        '@babel/proposal-class-properties',
        '@babel/plugin-proposal-class-properties'
      ],
      babelrcRoots: [
          ".",
          "packages/*",
        ],
    };
  </code></pre>
  
  <p>I have configured the following babelrc in web and common folders. </p>
  
  <pre><code>{
      "presets": [
          "@babel/preset-env",
          "@babel/preset-react"
      ],
      "plugins": [
          [
            "@babel/plugin-proposal-class-properties"
          ]
      ]
  }
  </code></pre>
  
  <p>The package.json in common folder is:</p>
  
  <pre><code>{
    "name": "@wow/common",
    "version": "1.0.0",
    "description": "",
    "main": "dist/index.js",
    "scripts": {
      "build": "rimraf dist &amp;&amp; tsc",
      "watch": "tsc --watch"
    },
    "keywords": [],
    "author": "",
    "license": "ISC",
    "dependencies": {
      "react": "16.8.2",
      "react-native": "0.59.0-rc.1",
      "react-native-elements": "^1.1.0",
      "react-native-image-slider-box": "^1.0.5",
      "react-native-snap-carousel": "^3.8.0"
    },
    "devDependencies": {
      "@babel/plugin-proposal-class-properties": "^7.5.5",
      "@types/react-native": "0.57.36",
      "rimraf": "^2.6.3",
      "typescript": "3.3.3"
    }
  }
  </code></pre>
  
  <p>The package.json in web folder is:</p>
  
  <pre><code>{
    "name": "react-native-web-workout-series",
    "version": "0.1.0",
    "private": true,
    "dependencies": {
      "@types/jest": "24.0.5",
      "@types/node": "11.9.4",
      "@types/react": "16.8.3",
      "@types/react-dom": "16.8.1",
      "@wow/common": "1.0.0",
      "react": "^16.8.2",
      "react-art": "16.8.2",
      "react-dom": "^16.8.2",
      "react-native": "0.55.4",
      "react-native-modal": "^11.3.1",
      "react-native-web": "0.10.0",
      "react-scripts": "2.1.5",
      "typescript": "3.3.3"
    },
    "scripts": {
      "start": "cross-env SKIP_PREFLIGHT_CHECK=true react-scripts start",
      "build": "react-scripts build",
      "test": "react-scripts test",
      "eject": "react-scripts eject"
    },
    "eslintConfig": {
      "extends": "react-app"
    },
    "browserslist": [
      "&gt;0.2%",
      "not dead",
      "not ie &lt;= 11",
      "not op_mini all"
    ],
    "devDependencies": {
      "@babel/plugin-proposal-class-properties": "^7.5.5",
      "@types/react-native": "0.55.4",
      "babel-plugin-module-resolver": "^3.2.0",
      "cross-env": "^5.2.0"
    }
  }
  </code></pre>
  
  <p>I get the error when I run the </p>
  
  <pre><code>yarn start 
  </code></pre>
  
  <p>command in web folder (the command works perfectly when I execute it without the Modal module). </p>
  
  <p>What am I missing?</p>