Support augmented global properties

[Shinigami92]

Vue has something like this: https://vuejs.org/guide/typescript/options-api.html#augmenting-global-properties

@antfu suggested to try out to support this, so plugin authors can define their own TypeScript definitions and eslint-define-config would then just use these.

So code in the specific plugin projects would look like this:

import type { DeprecationRuleConfig } from './rules/deprecation/deprecation';

declare module 'eslint-define-config' {
  interface Rules {
    /**
     * Do not use deprecated APIs.
     *
     * @see [deprecation](https://github.com/gund/eslint-plugin-deprecation)
     */
    'deprecation/deprecation'?: DeprecationRuleConfig;
  }
}

import type { AdjacentOverloadSignaturesRuleConfig } from './rules/typescript-eslint/adjacent-overload-signatures';
// ...

declare module 'eslint-define-config' {
  interface Rules {
    /**
     * Require that function overload signatures be consecutive.
     *
     * @see [adjacent-overload-signatures](https://typescript-eslint.io/rules/adjacent-overload-signatures)
     */
    '@typescript-eslint/adjacent-overload-signatures'?: AdjacentOverloadSignaturesRuleConfig;
    // ...
  }
}

[ST-DDT]

When this is explored, maybe it is time to move this library/feature to the eslint main repository. 🤔

[antfu]

That would be nice, especially now with the Flat Config users can alias plugins to have different prefixes, this would also such configs still provide type safety

[Shinigami92]

More context: https://www.typescriptlang.org/docs/handbook/declaration-merging.html#module-augmentation

[Shinigami92]

Started some first experiments, and it seems to work 🚀