¹ In my case Google Chrome Version 98.0.4758.102, 64-bit. Running on Windows 10.

² Install the project (locally) by running npm install – this may take about 5-9 minutes.
Then run npm start to open the project in the default web browser.

For a simple Create React App project, I run npm install. Then npm start opens the default web browser¹. Pressing F12 displays two error messages in the console.

The error messages are:

• Uncaught ReferenceError: process is not defined, and
• Line 0: Parsing error: ImportDeclaration should appear when the mode is ES6 and in the module context.

What should I do to rectify these errors?

I have seen these errors elsewhere, sometimes referring to version issues of the packages in package.json.
See the reference list below. I believe references 3-6 may be related to the issues here.

The .eslintrc.json and package.json files are provided below.
But since they will hardly be sufficient to reproduce the error,
here is a link to a zip file containing all the necessary project files. ²

.eslintrc.json :

{
  "env": {
    "browser": true,
    "es2021": true
  },
  "extends": [
    "eslint:remended",
    "plugin:react/remended"
  ],
  "parserOptions": {
    "ecmaFeatures": {
      "jsx": true
    },
    "ecmaVersion": "latest",
    "sourceType": "module"
  },
  "plugins": [
    "react"
  ],
  "rules": {
    "no-unused-vars": [
      "warn",
      {
        "argsIgnorePattern": "^_",
        "varsIgnorePattern": "^_"
      }
    ]
  }
}

package.json :

{
  "name": "Uncaught ReferenceError",
  "dependencies": {
    "@testing-library/jest-dom": "^4.2.4",
    "@testing-library/react": "^9.4.1",
    "@testing-library/user-event": "^7.2.1",
    "react": "^17.0.2",
    "react-dom": "^17.0.2",
    "react-scripts": "4.0.3"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject"
  },
  "eslintConfig": {
    "extends": "react-app"
  },
  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version"
    ]
  },
  "devDependencies": {
    "eslint": "^7.32.0",
    "eslint-plugin-react": "^7.29.2"
  }
}

References

• Create React App (CRA)
• Zip file containing the needed project files
• React Uncaught ReferenceError: process is not defined
• process is not defined on hot reload
• Line 0: Parsing error: Cannot read property 'map' of undefined
• React Typescript: Line 0: Parsing error: Cannot read property 'name' of undefined

npm install --global npm-check-updates

npm-check-updates

npm-check-updates --upgrade

npm install

npm start