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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.
• I have read the FAQ and my problem is not listed.

Relevant Package

types

ESLint Config

import tseslint from 'typescript-eslint';

// v8 alpha
export default tseslint.config(
  {
    languageOptions: {
      parserOptions: {
        projectService: {
          allowDefaultProject: ['./*.js'],
          defaultProject: './tsconfig.json',
        },
      },
    },
  },
);

// v7
export default tseslint.config(
  {
    languageOptions: {
      parserOptions: {
        EXPERIMENTAL_useProjectService: {
          allowDefaultProject: ['./*.js'],
          defaultProject: './tsconfig.json',
        },
      },
    },
  },
);

tsconfig

{
  "compilerOptions": {
    "allowJs": true,
    "checkJs": true,
  }
}

Expected Result

Config should not have a type error.

Actual Result

On line 7, there is an error.
On v8 alpha:

Type '{ allowDefaultProject: string[]; defaultProject: string; }' is not assignable to type 'boolean'.ts(2322)
parser-options.d.ts(30, 5): The expected type comes from property 'projectService' which is declared here on type 'ParserOptions'

On v7:

Type '{ allowDefaultProject: string[]; defaultProject: string; }' is not assignable to type 'boolean'.ts(2322)
parser-options.d.ts(25, 5): The expected type comes from property 'EXPERIMENTAL_useProjectService' which is declared here on type 'ParserOptions'

Additional Info

Config is adapted from https://typescript-eslint.io/blog/announcing-typescript-eslint-v8-beta/#project-service.
At a glance, it seems like there is a type mismatch between

Versions

v8 alpha

v7