fix: remove unused types from types.ts

[lumirlumir]

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What is the purpose of this pull request?

Hello,

While reviewing the types.ts file, I noticed that Message and RuleType are not used anywhere.

It seems these two types were not removed during the refactor.

I think removing unused types would be helpful, but I'm not sure if this should be considered a breaking change, since users can import types from types.ts via @eslint/markdown/types, and version 7 was just released.

On the other hand, since these types were likely included by mistake during a refactor, it might make sense to treat their removal as a fix.

I'd be interested to hear team's thoughts on how we should handle these unused types.

(Personally, I don't think these two types play an important role in the markdown plugins.)

What changes did you make? (Give an overview)

Related Issues

Is there anything you'd like reviewers to focus on?

[JoshuaKGoldberg]

In general, Knip is great at solving unused types and the like. Unfortunately it can't detect this specific issue because types.ts is an entry point per package.json > "exports". From Knip's perspective, anything that is exported from an entry point is "used". Sent: #466.

I suppose we could write a custom lint rule or similar for things that exist and are exported in one file, do not refer to existing types, and are not used elsewhere? That's quite niche.

[JoshuaKGoldberg]

✂️

[fasttime]

In general, Knip is great at solving unused types and the like. Unfortunately it can't detect this specific issue because types.ts is an entry point per package.json > "exports". From Knip's perspective, anything that is exported from an entry point is "used". Sent: #466.

I suppose we could write a custom lint rule or similar for things that exist and are exported in one file, do not refer to existing types, and are not used elsewhere? That's quite niche.

Exported types in src/types.ts are reflected in the generated file dist/esm/types.d.ts, and since that file is publicly exported, there is no way to determine automatically that some types in it are unused. In fact, all exported types could be imported and used by some consumers. Maybe a clearer description of the issue is to say that the Message and RuleType types are unnecessary because they duplicate types defined elsewhere, and they aren't used internally.

[lumirlumir]

The Message type was moved to processor.js internally after I made this change: #367. So, that was my mistake for not removing it.

As for RuleType, I found that it was added in #268, but I noticed it wasn’t actually used at that time either. So, I’m not sure where this type is currently being used.

I've also searched for it on GitHub, but it looks like ESLint doesn’t use this type internally.

https://github.com/search?q=%40eslint%2Fmarkdown%2Ftypes&type=code

[fasttime]

As for RuleType, I found that it was added in #268, but I noticed it wasn’t actually used at that time either. So, I’m not sure where this type is currently being used.

I think it's safe to remove RuleType in a regular fix since that type isn't documented or otherwise referenced in this plugin. There are also no indications that that type is used by externally.

[fasttime]

LGTM, thanks!