make Remark rehype options available in astro config

[gtnbssn]

Changes

• Allows to set remark-rehype options in astro.config.mjs
• See options here https://github.com/remarkjs/remark-rehype#options
• Astro has {allowDangerousHtml: true, passThrough: ["raw", "mdxTextExpression", "mdxJsxTextElement", "mdxJsxFlowElement"]} by default, this keeps them and will extend the values with what goes in the astro.config.mjs
• This should allow to set other options, notably footerLabel to close 🐛 BUG: footnotes in markdown generate a <h2 id="footnote-label" class="sr-only">Footnotes</h2> that cannot be translated or removed #3163

Testing

Add this in astro.config.mjs

markdown: {
  remarkRehype: {
    footnoteLabel : "other title for footnotes",
    footnoteBackLabel: 'other text for the link back to content',
  }
}

Create a markdown page with a least one footnote and check that the title for the footnotes section has been updated.

Docs

I'll update (if necessary) and reopen docs#445 if this passes.

[changeset-bot]

🦋 Changeset detected

Latest commit: 2f2271d

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 15 packages

Name	Type
astro	Minor
@astrojs/markdown-remark	Minor
@e2e/astro-component	Patch
@e2e/error-react-spectrum	Patch
@e2e/error-sass	Patch
@e2e/errors	Patch
@e2e/hydration-race	Patch
@e2e/lit-component	Patch
@e2e/preact-component	Patch
@e2e/react-component	Patch
@e2e/solid-component	Patch
@e2e/solid-recurse	Patch
@e2e/svelte-component	Patch
@e2e/e2e-tailwindcss	Patch
@e2e/ts-resolution	Patch

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[gtnbssn]

@EiffelFly i think this is it! I had to explicitly import the types for handlers and add them back in the RemarkRehype type.

I don't think the failing tests are related to this patch so hopefully this is ok.

[bholmesdev]

Making a note to pull this from the MDX integration! I'll make a separate PR for that when this is merged 👍

[backflip]

@bholmesdev, should this work with MDX already? The following config does not overwrite the title for me when using .mdx files:

export default defineConfig({
  integrations: [
    mdx(),
  ],
  markdown: {
    remarkRehype: {
      footnoteLabel: "Hi Ben",
    },
  },
});

@astro/mdx@0.11.6

[backflip]

@bholmesdev, I guess we would have to pass remarkRehypeOptions: config.markdown.remarkRehype to https://github.com/withastro/astro/blob/main/packages/integrations/mdx/src/index.ts#L65

Is this something you would want to combine with custom remarkRehypeOptions on mdxOptions and something like extendOptions to define the inheritance behavior?

[bholmesdev]

@backflip Ah, right you are! I agree this should be applied when extendPlugins: 'markdown' is set in your MDX config (which is the default). We'd likely apply the remark-rehype plugin alongside your other remark plugins if this option is set.