Fix cases for JSX-like expressions in code blocks of headings

[nokazn]

Changes

I fixed cases to render incorrectly JSX-like expressions in code blocks of headings.
See also #3491 for details.

Testing

Add test cases including JSX-like expressions in code blocks of headings like below.

# `{frontmatter.title}`

# `{ foo }` is a shorthand for `{ foo: foo }`

###### `{}` is equivalent to `Record<never, never>` <small>(at TypeScript v{frontmatter.version})</small>

Docs

N/A

Related

• close 🐛 BUG: JSX-like expressions in code blocks are rendered incorrectly in headings #3491

[changeset-bot]

🦋 Changeset detected

Latest commit: fb69531

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

This PR includes changesets to release 2 packages

Name	Type
@astrojs/markdown-remark	Minor
astro	Patch

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[matthewp]

I think that the way you are doing this but skipping any nodes where the parent is a code/pre entirely will cause there to be no id if there is only a codeblock and nothing else.

To test this, create a test for:

await renderMarkdown(`# \`{frontmatter.title}\``, {})

That should still render some id. In my branch that was making the id be "frontmattertitle". See https://github.com/withastro/astro/pull/3510/files

Happy to go with your approach in general, just want to make sure we handle this case.

[matthewp]

please use an object or Set here to avoid an unnecessary O(2) lookup.

[nokazn]

changed to use Set to scan parent.tagName in fb69531

[nokazn]

@matthewp
Thank you for your feedback.

I think that the way you are doing this but skipping any nodes where the parent is a code/pre entirely will cause there to be no id if there is only a codeblock and nothing else.

This case was not considered, then fixed by fb69531

[matthewp]

Looks great, thanks!