如何修复React中的“模块构建失败”错误？

Question

我不知道为什么在装饰器上使用mobx-react时会发生此错误，但是有错误。我想将mobx与装饰器一起使用，如何解决此问题以正确使用mobx？

错误：

./src/index.js
SyntaxError: D:\my-app\src\index.js: Unexpected token (9:2)

   7 | 
   8 | ReactDOM.render(
>  9 |   <div>
     |   ^
  10 |   <App />
  11 |   <DevTools />
  12 |   </div>, document.getElementById('root'));

package.json：

{
  "name": "my-app",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "@babel/core": "7.5.5",
    "@material-ui/core": "^4.3.3",
    "@svgr/webpack": "4.3.2",
    "@typescript-eslint/eslint-plugin": "1.13.0",
    "@typescript-eslint/parser": "1.13.0",
    "babel-eslint": "10.0.2",
    "babel-jest": "^24.8.0",
    "babel-plugin-named-asset-import": "^0.3.3",
    "babel-preset-react-app": "^9.0.1",
    "camelcase": "^5.2.0",
    "case-sensitive-paths-webpack-plugin": "2.2.0",
    "css-loader": "2.1.1",
    "dotenv": "6.2.0",
    "dotenv-expand": "4.2.0",
    "eslint": "^6.1.0",
    "eslint-config-react-app": "^5.0.1",
    "eslint-loader": "2.2.1",
    "eslint-plugin-flowtype": "3.13.0",
    "eslint-plugin-import": "2.18.2",
    "eslint-plugin-jsx-a11y": "6.2.3",
    "eslint-plugin-react": "7.14.3",
    "eslint-plugin-react-hooks": "^1.6.1",
    "file-loader": "3.0.1",
    "fs-extra": "7.0.1",
    "html-webpack-plugin": "4.0.0-beta.5",
    "identity-obj-proxy": "3.0.0",
    "is-wsl": "^1.1.0",
    "jest": "24.8.0",
    "jest-environment-jsdom-fourteen": "0.1.0",
    "jest-resolve": "24.8.0",
    "jest-watch-typeahead": "0.3.1",
    "mini-css-extract-plugin": "0.5.0",
    "mobx": "^5.13.0",
    "mobx-react": "^6.1.3",
    "optimize-css-assets-webpack-plugin": "5.0.3",
    "pnp-webpack-plugin": "1.5.0",
    "postcss-flexbugs-fixes": "4.1.0",
    "postcss-loader": "3.0.0",
    "postcss-normalize": "7.0.1",
    "postcss-preset-env": "6.7.0",
    "postcss-safe-parser": "4.0.1",
    "react": "^16.9.0",
    "react-app-polyfill": "^1.0.2",
    "react-dev-utils": "^9.0.3",
    "react-dom": "^16.9.0",
    "resolve": "1.12.0",
    "resolve-url-loader": "3.1.0",
    "sass-loader": "7.2.0",
    "semver": "6.3.0",
    "style-loader": "1.0.0",
    "terser-webpack-plugin": "1.4.1",
    "ts-pnp": "1.1.2",
    "url-loader": "2.1.0",
    "webpack": "4.39.1",
    "webpack-dev-server": "3.2.1",
    "webpack-manifest-plugin": "2.0.4",
    "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"
  },
  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  },
  "devDependencies": {
    "@babel/core": "7.5.5",
    "@babel/preset-env": "7.5.5",
    "babel-loader": "8.0.6",
    "@babel/plugin-proposal-class-properties": "7.5.5",
    "@babel/plugin-proposal-decorators": "^7.4.4",
    "vuex-module-decorators": "^0.10.1"
  },
  "babel": {
    "presets": [
      "@babel/preset-env", "@babel/preset-react"
    ],
    "plugins": [
      [
        "@babel/plugin-proposal-decorators",
        {
          "legacy": true
        }
      ],
      [
        "@babel/plugin-proposal-class-properties",
        {
          "loose": true
        }
      ]
    ]
  }
}