Before You File a Proposal Please Confirm You Have Done The Following...

• I have searched for related issues and found none that match my proposal.
• I have searched the current rule list and found no rules that match my proposal.
• I have read the FAQ and my problem is not listed.

Relevant Package

parser

My proposal is suitable for this project

• I believe my proposal would be useful to the broader TypeScript community (meaning it is not a niche proposal).

Description

I expect that these should throw (when validating parser options):

import tseslint from 'typescript-eslint';

export default tseslint.config(
  tseslint.configs.strictTypeChecked,
  {
    languageOptions: {
      parserOptions: {
        projectService: true,
        tsconfigRootDir: 'not/an/absolute/path',
      }
    }
  }
);

(or tsconfigRootDir: 42, or tsconfigRootDir: '.').

In other words, I think the following...

...should have (roughly)

assert(
  tsestreeOptions.tsconfigRootDir == null ||
    (typeof tsestreeOptions.tsconfigRootDir === "string" &&
      path.isAbsolute(tsestreeOptions.tsconfigRootDir)),
);

Additional Info

Relates to #11414, #11429