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• 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.
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Relevant Package

utils

Playground Link

https://www.typescriptlang.org/play/?#code/PTAEAEBcGcFoGMAWBTeBrAUBglgWwA4D2ATpKDMtADbYB2ZAZsYbqAESQCe+l8x2+SLEo16bANw4CJMgG9QdeFQCuAE2QBJAOa0SyAGLYqyUAF9QTFu3Ai6kYPBb4AhpAlZkADyKlQ6hs7KVGQU1HYAdI60DNhaABSKKurausQGRshxbFrYkLGpyGwAlEWSQA

Repro Code

// @ts-check

import tseslint from "typescript-eslint";
import { includeIgnoreFile } from "@eslint/compat";

export default tseslint.config(includeIgnoreFile("gitignore"));

ESLint Config

n/a

tsconfig

{
  "compilerOptions": {
    "allowJs": true,
    "module": "NodeNext",
    "skipLibCheck": true,
    "noEmit": true
  }
}

Expected Result

There should be no type errors.

Actual Result

$ pnpm tsc
eslint.config.js:6:32 - error TS2345: Argument of type 'FlatConfig' is not assignable to parameter of type 'ConfigWithExtends'.
  The types of 'languageOptions.globals' are incompatible between these types.
    Type 'Globals' is not assignable to type 'GlobalsConfig'.
      'string' index signatures are incompatible.
        Type 'GlobalConf' is not assignable to type 'GlobalVariableOption'.
          Type '"readable"' is not assignable to type 'GlobalVariableOption'.

6 export default tseslint.config(includeIgnoreFile("gitignore"));
                                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


Found 1 error in eslint.config.js:6

Additional Info

What's happening is that we don't allow 'readable or 'writeable', while @types/eslint does.

On the typescript-eslint side:

type GlobalVariableOptionBase = 'off' | 'readonly' | 'writable';
type GlobalVariableOption = GlobalVariableOptionBase | boolean;
interface GlobalsConfig {
    [name: string]: GlobalVariableOption;
}

On the @types/eslint side:

type GlobalConf = boolean | "off" | "readable" | "readonly" | "writable" | "writeable";

interface Globals {
    [name: string]: GlobalConf;
}

From https://archive.eslint.org/docs/7.0.0/user-guide/configuring:

For historical reasons, the boolean value false and the string value "readable" are equivalent to "readonly". Similarly, the boolean value true and the string value "writeable" are equivalent to "writable". However, the use of older values is deprecated.

I think this means we'll need to add the two deprecated string literal types?

Originally reported by @romanstetsyk in https://discord.com/channels/1026804805894672454/1270028825857626193/1270028825857626193. Thanks! 🙌

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