Bug: Getting `TypeError: Nested 'extends' is not allowed.`

[vbeffa]

Before You File a Bug Report Please Confirm You Have Done The Following...

• I have tried restarting my IDE and the issue persists.
• I have updated to the latest version of the packages.
• I have searched for related issues and found none that matched my issue.
• I have read the FAQ and my problem is not listed.

Relevant Package

typescript-eslint

Playground Link

No response

Repro Code

I am trying to update my project to the latest version of eslint-plugin-react-hooks and in doing so had to redo my entire eslint.config.js. See config below. I stripped everything out to the minimum to still reproduce the error. When I run the linter, I get the error shown in Actual Result. I've searched for it and can't find another instance of it.

ESLint Config

import { defineConfig } from 'eslint/config';
import tseslint from '@typescript-eslint/eslint-plugin';

export default defineConfig(
  {
    files: ['**/*.ts', '**/*.tsx', '**/*.js'],
    extends: [
      tseslint.configs.recommended,
    ]
  }
);

tsconfig

{
  "compilerOptions": {
    // ...
  }
}

Expected Result

I don't have a nested extends, so I would expect the linter to work with my config.

Actual Result

❯ npm run lint

> vite-project@0.0.0 lint
> eslint .


Oops! Something went wrong! :(

ESLint: 9.39.1

TypeError: Nested 'extends' is not allowed.
    at processExtends (./node_modules/@eslint/config-helpers/dist/cjs/index.cjs:462:10)
    at ./node_modules/@eslint/config-helpers/dist/cjs/index.cjs:504:38
    at Array.flatMap (<anonymous>)
    at processConfigList (./node_modules/@eslint/config-helpers/dist/cjs/index.cjs:504:20)
    at defineConfig (./node_modules/@eslint/config-helpers/dist/cjs/index.cjs:540:9)
    at file://./eslint.config.js?mtime=1762380747314:5:16
    at ModuleJob.run (node:internal/modules/esm/module_job:371:25)
    at async onImport.tracePromise.__proto__ (node:internal/modules/esm/loader:669:26)
    at async dynamicImportConfig (./node_modules/eslint/lib/config/config-loader.js:186:17)
    at async loadConfigFile (./node_modules/eslint/lib/config/config-loader.js:276:9)

Additional Info

No response

Versions

package	version
TypeScript	5.9.3
ESLint	9.39.1
node	24.6.0

[vbeffa]

It also appears that a directive like

    extends: [
      reactHooks.configs['recommended-latest']
    ],

is not recognized, as I get the error

ESLint: 9.39.1


A config object has a "plugins" key defined as an array of strings. It looks something like this:

    {
        "plugins": ["react-hooks"]
    }

Flat config requires "plugins" to be an object, like this:

    {
        plugins: {
            react-hooks: pluginObject
        }
    }

[vbeffa]

I can, however, successfully run the linter with

import reactRefresh from 'eslint-plugin-react-refresh';

...

    extends: [
      reactRefresh.configs.vite
    ],
...

[bradzacher]

https://typescript-eslint.io/getting-started/

You're importing our config from the wrong package.
Please review our getting started guide for details on how to correctly setup your config.