Add missing dependency for types

[Methuselah96]

Initial checklist

• I read the support docs
• I read the contributing guide
• I agree to follow the code of conduct
• I searched issues and couldn’t find anything (or linked relevant results below)
• If applicable, I’ve added docs and tests

Description of changes

Fix these build errors:

ERROR in ../../.yarn/cache/mdast-util-gfm-npm-2.0.0-177231f942-70c35ee810.zip/node_modules/mdast-util-gfm/index.d.ts 12:44-70
TS2307: Cannot find module 'mdast-util-from-markdown' or its corresponding type declarations.
    10 |   options?: import('mdast-util-gfm-table').Options | undefined
    11 | ): ToMarkdownExtension
  > 12 | export type FromMarkdownExtension = import('mdast-util-from-markdown').Extension
       |                                            ^^^^^^^^^^^^^^^^^^^^^^^^^^
    13 | export type ToMarkdownExtension = import('mdast-util-to-markdown').Options
    14 | export type Options = import('mdast-util-gfm-table').Options
    15 |

ERROR in ../../.yarn/cache/mdast-util-gfm-npm-2.0.0-177231f942-70c35ee810.zip/node_modules/mdast-util-gfm/index.d.ts 13:42-66
TS2307: Cannot find module 'mdast-util-to-markdown' or its corresponding type declarations.
    11 | ): ToMarkdownExtension
    12 | export type FromMarkdownExtension = import('mdast-util-from-markdown').Extension
  > 13 | export type ToMarkdownExtension = import('mdast-util-to-markdown').Options
       |                                          ^^^^^^^^^^^^^^^^^^^^^^^^
    14 | export type Options = import('mdast-util-gfm-table').Options
    15 |

[wooorm]

FromMarkdownExtension and ToMarkdownExtension are not supposed to be exported types.
Unfortunately, in TS through JSDoc, you can’t differentiate between local and exported typedefs.
One way to solve that is by putting stuff in a lib/ and exporting only intentional things from there: https://github.com/remarkjs/remark-rehype/blob/main/index.js.
I’m hoping that would also work in this case, and for your plug and play problems?

[Methuselah96]

I don't think that will work because the gfmFromMarkdown and gfmToMarkdown function types still need to reference those types by importing them from mdast-util-from-markdown and mdast-util-to-markdown. Would it make sense to have a mdast-util-types package where the types could be shared without having to depend on the logic?

[wooorm]

This sounds like a bunch of work that is meaningless and inexplicable to anyone else, but specifically meant to solve a TS issue which only occurs with pnp.

Say someone else makes an extension, how would they know about this?

Perhaps you can not use pnp? Or you can use skipLibCheck?

[Methuselah96]

This sounds like a bunch of work that is meaningless and inexplicable to anyone else, but specifically meant to solve a TS issue which only occurs with pnp.

This is not a TS or Yarn PnP issue. The issue is that this package imports a type from another package that it doesn't have a dependency on. That's an issue for the same reason it would be an issue to import a JS function from a package with npm without having a dependency on it, right?

[wooorm]

My last comment was in response to your idea for introducing mdast-util-types, and I conflated this PR with some of your other PRs (notable react-markdown) in my head.

Reading this particular code again, my earliest assessment was incorrect (#1 (comment)). This utility does expose extensions. Still, my proposed lib/ would also help clean types and prevent FromMarkdownExtension and ToMarkdownExtension from being exported on their own.

[Methuselah96]

Makes sense, sorry for the confusion. Is syntax-tree/mdast-util-gfm-table#2 in the same boat?

[wooorm]

Thanks, released!