'React' was used before it was defined

Reactjs Typescript Create React-App Eslint

Reactjs Problem Overview

I am working with create-react-app + typescript + eslint application and during build have such error:

Line 1:8:  'React' was used before it was defined  @typescript-eslint/no-use-before-define

Code in my component starts with:

import React from "react";

Eslint settings:

module.exports = {
  parser: "@typescript-eslint/parser",
  parserOptions: {
    ecmaVersion: 2020,
    sourceType: "module",
    ecmaFeatures: {
      jsx: true
    }
  },
  settings: {
    react: {
      version: "detect"
    }
  },
  extends: [
    "plugin:react/recommended",
    "plugin:@typescript-eslint/recommended",
    "prettier/@typescript-eslint",
    "plugin:prettier/recommended"
  ],
  rules: {
    "@typescript-eslint/explicit-module-boundary-types": 0,
    "@typescript-eslint/triple-slash-reference": 0,
    "no-use-before-define": "off",
    "@typescript-eslint/no-use-before-define": "off"
  },
};

Some part of package.json:

"devDependencies": {
  "@typescript-eslint/eslint-plugin": "^4.1.0",
  "@typescript-eslint/parser": "^4.1.0",
  "babel-eslint": "^10.1.0",
  "eslint": "^6.6.0",
  "eslint-config-airbnb": "^18.1.0",
  "eslint-config-prettier": "^6.11.0",
  "eslint-plugin-import": "^2.20.2",
  "eslint-plugin-prettier": "^3.1.3",
  "eslint-plugin-react": "^7.20.0",
  "prettier": "^2.0.5",
  "start-server-and-test": "^1.11.3"
},
"dependencies": {
  ...
  "react-scripts": "3.4.3",
  ...
}

I tried:

Read https://github.com/typescript-eslint/typescript-eslint/issues/2502
Disable @typescript-eslint/no-use-before-define and no-use-before-define in .eslintrc.js
Actually I tried to delete .eslintrc.js at all, but had the same error.

Reactjs Solutions

Solution 1 - Reactjs

From the official documentation.

"rules": {
  // note you must disable the base rule as it can report incorrect errors
  "no-use-before-define": "off",
  "@typescript-eslint/no-use-before-define": ["error"]
}

Solution 2 - Reactjs

The bug occurs due to mismatch of @typescript-eslint versions in react-scripts and your local package.json - GitHub issue

You can downgrade the packages until react-scripts updates their version.

    "@typescript-eslint/eslint-plugin": "4.0.1",
    "@typescript-eslint/parser": "4.0.1",

EDIT 2020-09-14

It seems the bug is not related to react-scripts version of @typescript-eslint since multiple people reported the same bug without using react-scripts.

Anyway, the workaround remains the same - downgrade to the working version of @typescript-eslint until the fix is available.

EDIT 2020-10-24

[email protected] has been published with updated @typescript-eslint. Using the newest version should solve the issue.

EDIT 2020-11-04

If after upgrading the packages the error is still there, most probably your eslint config uses the wrong rule. Check out Igor's answer to fix it.

Solution 3 - Reactjs

If you are only getting this error for .js files, make sure @typescript-eslint/parser is being used exclusively on Typescript files.

.eslintrc.json (abbreviated)

{
  "overrides": [
    {
      "files": ["**/*.ts", "**/*.tsx"],
      "plugins": ["@typescript-eslint"],
      "rules": {
        "no-use-before-define": "off",
        "@typescript-eslint/no-use-before-define": ["error"],
      },
    }
  ],
  // WRONG: Do not use @typescript-eslint/parser on JS files
  // "parser": "@typescript-eslint/parser",
  "plugins": [
    "react",
    // "@typescript-eslint"
  ],
}

Solution 4 - Reactjs

That is how I resolved my problem.

First of all, go to the node_modules/react-scripts/config/webpack.config.js and change cache to false, because this will help you to understand what works and what is not then you changing eslint file. I found it here

 cache: true, // You can set it to false
 formatter: require.resolve('react-dev-utils/eslintFormatter'),

Add ENV varialbe to .env file. More info

 EXTEND_ESLINT=true

From now CRA will have to use your local eslint for linting during your build and we have control to disable some rules, in my case in .eslintrc:

rules: {
    "@typescript-eslint/no-use-before-define": "off"
},

Solution 5 - Reactjs

I landed on this page after I started getting issues with a Gatsby project that was using Typescript and an ESLint config that extended eslint-config-airbnb-typescript. In addition to OP's error, ESLint was also giving errors on various rules not being defined, like Definition for rule '@typescript-eslint/no-redeclare' was not found. and a few others.

The underlying problem ended up being that Gatsby was using fairly old versions of both @typescript-eslint/eslint-plugin and @typescript-eslint/parser. Forcing yarn to install only up-to-date versions solved the issue:

// package.json
"resolutions": {
    "@typescript-eslint/eslint-plugin": "^4.4.0",
    "@typescript-eslint/parser": "^4.4.0"
}

Solution 6 - Reactjs

My fix for that: Use eslint 6 as react-scripts is using Force react scripts to use newer @typescript-eslint packages as the rest of the repo. I'm using selective resolution here

  "resolutions": {
    "**/react-scripts/**/@typescript-eslint/eslint-plugin": "^4.4.1",
    "**/react-scripts/**/@typescript-eslint/parser": "^4.4.1"
  }

@typescript-eslint 4.x does still support es6

Solution 7 - Reactjs

I got this error from the airbnb-base ruleset in a typescript project. Also extending airbnb-typescript (that has the correct rules for typescript) resolved the issue.

Solution 8 - Reactjs

I just wanted to add that for me, I did the following.

Removed all eslint related dependencies from package.json if they were already included in package-lock.json by react-scripts (for me that was all of them)
Deleted my node_modules folder, and package-lock.json file
Ran npm install

After completing those steps I finally got that error to go away. I prefer removing the dependencies to downgrading them since this will help avoid the same issue happening again in the future.

Solution 9 - Reactjs

This has been resolved in 4.4.0. Upgrade these dependencies to version 4.4.0

Update: This may work for some use cases. This resolved my issue.

"@typescript-eslint/eslint-plugin": "^4.4.0",
"@typescript-eslint/parser": "^4.4.0",

Solution 10 - Reactjs

Try adding import/resolver to your Eslint settings:

  "settings": {
    "react": { "version": "detect" },
    "import/resolver": { "typescript": {} }
  }

Maybe you will need to install it too:

$ yarn add -D eslint-import-resolver-typescript

If that doesn't work, you could change this rule

"@typescript-eslint/no-use-before-define": "off"

like this:

"no-use-before-define": "off"

Solution 11 - Reactjs

It is an issue present in ESLINT.

The way I resolve is to add the following lines to the ESLINT/rules:

"no-use-before-define": [0],
"@ typescript-eslint / no-use-before-define": [1],

Solution 12 - Reactjs

If you use Create React App. Getting the latest version of react-scripts fixed this issue for me. Currently: 4.0.3

// Get this specific version:
npm uninstall react-scripts
npm install react-scripts@4.0.3

// Get latest version:
npm uninstall react-scripts
npm install react-scripts

Solution 13 - Reactjs

(not enough rep to comment)

@sashko's workaround seems to work - deleting node_modules was necessary as well.

One thing I missed was the caret in "^4.0.1". The version needs to be fixed without the caret ^, which seems to be the issue that @Rolly is having. Make sure it's 4.0.1.

Only a workaround until react-scripts updates to v4 (I'm using create-react-app)

Solution 14 - Reactjs

deleting the node_modules folder and reinstalling it worked for me. I'm using yarn as package manager.

Solution 15 - Reactjs

I deleted packages @typescript-eslint/eslint-plugin and @typescript-eslint/parser from my package.json, deleted node_modules and package-lock.json, reinstalled packages: npm install The error disappeared.

UPDATE

After that create-react-app uses their own @typescript-eslint/eslint-plugin module which is deprecated.

Solution 16 - Reactjs

I know that this post does not solve the issue directly, but you can bypass this issue if you stick to best practices regarding imports. Try to import exactly what you want, and you will get rid of this error also. For example:

import { useState, useEffect } from React;
// and then continue with your code

Solution 17 - Reactjs

This Answer worked for me in a react-native project(airbnb style guide)

Extend your rules with airbnb-typescript inside the .eslintrc.json

"extends": {
  "airbnb-typescript"
}

Press ctrl+shift+p or cmd+shift+p >Reload window (or simply close and re-open vscode)

Solution 18 - Reactjs

Try using Yarn instead of NPM (make sure to remove your node_modules in between).

This worked for me.

Content Type	Original Author	Original Content on Stackoverflow
Question	Alexey Nazarov	View Question on Stackoverflow
Solution 1 - Reactjs	igor	View Answer on Stackoverflow
Solution 2 - Reactjs	sashko	View Answer on Stackoverflow
Solution 3 - Reactjs	Raine Revere	View Answer on Stackoverflow
Solution 4 - Reactjs	Alexey Nazarov	View Answer on Stackoverflow
Solution 5 - Reactjs	j0hnm4r5	View Answer on Stackoverflow
Solution 6 - Reactjs	Bnaya	View Answer on Stackoverflow
Solution 7 - Reactjs	thisismydesign	View Answer on Stackoverflow
Solution 8 - Reactjs	St. John	View Answer on Stackoverflow
Solution 9 - Reactjs	etoxin	View Answer on Stackoverflow
Solution 10 - Reactjs	Rodrigo Avellar	View Answer on Stackoverflow
Solution 11 - Reactjs	Jean Poffo	View Answer on Stackoverflow
Solution 12 - Reactjs	MapMyMind	View Answer on Stackoverflow
Solution 13 - Reactjs	jmaio	View Answer on Stackoverflow
Solution 14 - Reactjs	Presh Onyee	View Answer on Stackoverflow
Solution 15 - Reactjs	Eugene	View Answer on Stackoverflow
Solution 16 - Reactjs	prieston	View Answer on Stackoverflow
Solution 17 - Reactjs	Nivethan	View Answer on Stackoverflow
Solution 18 - Reactjs	antoine129	View Answer on Stackoverflow