title: How to activate the legacyDecorators option in babel?
body: <p>I want to use a Decorater for my component. However i encounter the following error message:</p>
  
  <pre><code>Parsing error: Using the export keyword between a decorator and a class is not allowed. Please use `export @dec class` instead.
  </code></pre>
  
  <p>I found the solution in the following <a href="https://stackoverflow.com/a/54516632/12818045">post</a> recommending to use the <code>legacyDecorators</code> option in the <code>.eslintrc</code> file.</p>
  
  <pre><code>{    
    "parserOptions": {
       "ecmaFeatures": {
         "legacyDecorators": true
       }
     }
  }
  
  </code></pre>
  
  <p>However, i have no idea where i have to insert that code to activate the legacy option.</p>
  
  <p><strong>Update</strong></p>
  
  <p>I meanwhile ejected my create-react-app and im now able to configure babel and eslint (eslintConfig) directly in package.jason as you see below.</p>
  
  <pre><code>{
    "name": "Test",
    "version": "0.1.0",
    "private": true,
    "dependencies": {
      "@babel/core": "7.8.4",
      "@babel/runtime": "7.0.0-beta.55",
      "@fortawesome/fontawesome-free": "^5.13.0",
      "@material-ui/core": "^1.5.1",
      "@material-ui/icons": "^1.1.0",
      "@svgr/webpack": "4.3.3",
      "@testing-library/jest-dom": "^4.2.4",
      "@testing-library/react": "^9.4.0",
      "@testing-library/user-event": "^7.2.1",
      "@types/jest": "^24.9.1",
      "@types/node": "^12.12.28",
      "@types/react": "^16.9.21",
      "@types/react-dom": "^16.9.5",
      "@types/react-router-dom": "^5.1.3",
      "@typescript-eslint/eslint-plugin": "^2.10.0",
      "@typescript-eslint/parser": "^2.10.0",
      "axios": "^0.19.2",
      "babel-eslint": "10.0.3",
      "babel-jest": "^24.9.0",
      "babel-loader": "8.0.6",
      "babel-plugin-named-asset-import": "^0.3.6",
      "babel-preset-react-app": "^9.1.1",
      "bootstrap": "^4.4.1",
      "camelcase": "^5.3.1",
      "case-sensitive-paths-webpack-plugin": "2.3.0",
      "css-loader": "3.4.2",
      "d3-ease": "^1.0.6",
      "dotenv": "8.2.0",
      "dotenv-expand": "5.1.0",
      "eslint": "^6.6.0",
      "eslint-config-react-app": "^5.2.0",
      "eslint-loader": "3.0.3",
      "eslint-plugin-flowtype": "4.6.0",
      "eslint-plugin-import": "2.20.0",
      "eslint-plugin-jsx-a11y": "6.2.3",
      "eslint-plugin-react": "7.18.0",
      "eslint-plugin-react-hooks": "^1.6.1",
      "file-loader": "4.3.0",
      "fs-extra": "^8.1.0",
      "html-react-parser": "^0.10.3",
      "html-to-react": "^1.4.2",
      "html-webpack-plugin": "4.0.0-beta.11",
      "identity-obj-proxy": "3.0.0",
      "install": "^0.13.0",
      "jest": "24.9.0",
      "jest-environment-jsdom-fourteen": "1.0.1",
      "jest-resolve": "24.9.0",
      "jest-watch-typeahead": "0.4.2",
      "jquery": "^3.4.1",
      "material-kit-react": "^1.8.0",
      "mdbreact": "^4.25.5",
      "mini-css-extract-plugin": "0.9.0",
      "npm": "^6.14.2",
      "optimize-css-assets-webpack-plugin": "5.0.3",
      "pnp-webpack-plugin": "1.6.0",
      "postcss-flexbugs-fixes": "4.1.0",
      "postcss-loader": "3.0.0",
      "postcss-normalize": "8.0.1",
      "postcss-preset-env": "6.7.0",
      "postcss-safe-parser": "4.0.1",
      "prop-types": "^15.7.2",
      "pure-react-carousel": "^1.26.1",
      "react": "^16.12.0",
      "react-alert": "^6.0.1",
      "react-alert-template-basic": "^1.0.0",
      "react-app-polyfill": "^1.0.6",
      "react-audio-player": "^0.11.1",
      "react-bootstrap": "^1.0.0-beta.17",
      "react-bootstrap-carousel": "^4.0.3",
      "react-dev-utils": "^10.2.0",
      "react-dom": "^16.12.0",
      "react-geocode": "^0.2.1",
      "react-google-autocomplete": "^1.1.2",
      "react-google-maps": "^9.4.5",
      "react-h5-audio-player": "^2.4.2",
      "react-image-appear": "^1.2.23",
      "react-loading-image": "^0.5.0",
      "react-redux": "^7.2.0",
      "react-reveal": "^1.2.2",
      "react-router": "^5.1.2",
      "react-router-dom": "^5.1.2",
      "react-scroll": "^1.7.9",
      "react-select": "^3.1.0",
      "react-slick": "^0.23.1",
      "react-transition-group": "^4.3.0",
      "redux": "^4.0.5",
      "redux-devtools-extension": "^2.13.8",
      "redux-thunk": "^2.3.0",
      "resolve": "1.15.0",
      "resolve-url-loader": "3.1.1",
      "sass-loader": "8.0.2",
      "semver": "6.3.0",
      "slick-carousel": "^1.8.1",
      "style-loader": "0.23.1",
      "styled-components": "^5.0.1",
      "terser-webpack-plugin": "2.3.4",
      "ts-pnp": "1.1.5",
      "typescript": "^3.7.5",
      "url-loader": "2.3.0",
      "webpack": "4.41.5",
      "webpack-dev-server": "3.10.2",
      "webpack-manifest-plugin": "2.2.0",
      "workbox-webpack-plugin": "4.3.1"
    },
    "scripts": {
      "start": "node scripts/start.js",
      "build": "node scripts/build.js",
      "test": "node scripts/test.js"
    },
    "eslintConfig": {
      "extends": "react-app",
      "parser": "babel-eslint",
      "parserOptions": {
       "ecmaFeatures": {
         "legacyDecorators": true
       }
     }
    },
    "browserslist": {
      "production": [
        "&gt;0.2%",
        "not dead",
        "not op_mini all"
      ],
      "development": [
        "last 1 chrome version",
        "last 1 firefox version",
        "last 1 safari version"
      ]
    },
    "jest": {
      "roots": [
        "&lt;rootDir&gt;/src"
      ],
      "collectCoverageFrom": [
        "src/**/*.{js,jsx,ts,tsx}",
        "!src/**/*.d.ts"
      ],
      "setupFiles": [
        "react-app-polyfill/jsdom"
      ],
      "setupFilesAfterEnv": [],
      "testMatch": [
        "&lt;rootDir&gt;/src/**/__tests__/**/*.{js,jsx,ts,tsx}",
        "&lt;rootDir&gt;/src/**/*.{spec,test}.{js,jsx,ts,tsx}"
      ],
      "testEnvironment": "jest-environment-jsdom-fourteen",
      "transform": {
        "^.+\\.(js|jsx|ts|tsx)$": "&lt;rootDir&gt;/node_modules/babel-jest",
        "^.+\\.css$": "&lt;rootDir&gt;/config/jest/cssTransform.js",
        "^(?!.*\\.(js|jsx|ts|tsx|css|json)$)": "&lt;rootDir&gt;/config/jest/fileTransform.js"
      },
      "transformIgnorePatterns": [
        "[/\\\\]node_modules[/\\\\].+\\.(js|jsx|ts|tsx)$",
        "^.+\\.module\\.(css|sass|scss)$"
      ],
      "modulePaths": [],
      "moduleNameMapper": {
        "^react-native$": "react-native-web",
        "^.+\\.module\\.(css|sass|scss)$": "identity-obj-proxy"
      },
      "moduleFileExtensions": [
        "web.js",
        "js",
        "web.ts",
        "ts",
        "web.tsx",
        "tsx",
        "json",
        "web.jsx",
        "jsx",
        "node"
      ],
      "watchPlugins": [
        "jest-watch-typeahead/filename",
        "jest-watch-typeahead/testname"
      ]
    },
    "babel": {
      "presets": [
        "react-app"
      ],
      "plugins": [
        [
          "@babel/plugin-proposal-decorators",
          {
            "legacy": true
          }
        ]
      ]
    },
    "devDependencies": {
      "@babel/plugin-proposal-decorators": "^7.10.1"
    }
  }
  </code></pre>
  
  <p>I added the proposed lines under babel. However the same issue still appears.</p>