ESLint version

v9.22.0

What problem do you want to solve?

Hello,

Currently, the Rule.RuleModule type is not generic, which prevents me from extending the ExtRuleDocs property with custom properties.

Please take a look at the source code below.

https://github.com/eslint/eslint/blob/main/lib/types/index.d.ts#L554-L562

For example:

// @ts-check

/**
 * @typedef {import("eslint").Rule.RuleModule} RuleModule
 */

/** @type {RuleModule} */
export default {
  meta: {
    docs: {
      'my-custom-property': 'my-custom-property' // ❌This line causes a type error❌
      recommended: true,
    },
  },
}

When I try to add my-custom-property to meta.docs, I get a type error because ExtRuleDocs is simply initialized as {} with no way to extend its functionality.

I’d like to suggest adding support for generic types in Rule.RuleModule to allow for greater flexibility.

What do you think is the correct solution?

• Before: The RuleModule type cannot be extended.

-   type RuleModule = RuleDefinition<{
        LangOptions: Linter.LanguageOptions,
        Code: SourceCode,
        RuleOptions: any[],
        Visitor: NodeListener,
        Node: ESTree.Node,
        MessageIds: string,
-       ExtRuleDocs: {}
    }>;

• After: The RuleModule type can be extended using generics, allowing users to define custom types.

+   type RuleModule<ExtRuleDocs = {}> = RuleDefinition<{
        LangOptions: Linter.LanguageOptions,
        Code: SourceCode,
        RuleOptions: any[],
        Visitor: NodeListener,
        Node: ESTree.Node,
        MessageIds: string,
+       ExtRuleDocs: ExtRuleDocs,
    }>;

As a result, We can define a custom ExtRuleDocs type like the code below:

/**
 * @typedef {import("eslint").Rule.RuleModule<{ 'my-custom-property'?: string }>} RuleModule
 */

Please note that this change does not affect ESLint's current behavior. Looking forward to your comments on this!

Participation

• I am willing to submit a pull request for this change.

Additional comments

No response