[Internal Rule]: no-unused-messageId

Please describe what the rule should do: It should report whenever there is a message id defined in rule’s meta property but its not been used anywhere in the rule’s definition

What category of rule is this? (place an “X” next to just one item)

[ ] Warns about a potential error (problem) [ ] Suggests an alternate way of doing something (suggestion) [X] Enforces code style (layout) [ ] Other (please specify:)

Provide 2-3 code examples that this rule will warn about:

function checkMetaMessages(context, exportsNode) {
    if (!messages) {
        context.report({
            node: exportsNode,
            messageId: "used"
        });
      
    }
}


module.exports = {
    meta: {
        docs: {
            description: "",
            category: "Internal",
            recommended: false
        },
        schema: [],
        type: "suggestion",
        messages: {
          used: "Expected `meta.messages` property.",
          notUsed: "Expected `meta.messages` property."
      // ^^^ report here that this message id is not being used
        }
    },

    create(context) {
        return {
            "Program"(node) {
                checkMetaMessages(context, node);
            }
          
        };
    }
};

Why should this rule be included in ESLint (instead of a plugin)? Internal rule for eslint

Are you willing to submit a pull request to implement this rule? Yes, rough implementation

[aladdin-add]

it has been accepted in https://github.com/not-an-aardvark/eslint-plugin-eslint-plugin/issues/57

PRs are welcome! 😄

[anikethsaha]

Another suggestion: implement this rule into eslint-plugin-eslint-plugin.

yeah, this seems good as well 👍 .