Cannot parse `<!-- HTML comment -->`

[ferdinandant]

Subject of the issue

I updated my blog to use @mdx-js/loader v2.0.0-next.9, and it suddenly unable to parse HTML comments. (I used comments to put <!-- prettier-ignore -->)

Unexpected character `!` (U+0021) before name, expected a character that can start a name, such as a letter, `$`, or `_` (note: to create a comment in MDX, use `{/* text */}`)

Removing all <!-- --> in the file will fix the issue.

Your environment

• OS: MacOS 11.3.1 (20E241)
• Packages: @mdx-js/loader@2.0.0-next.9, next@11.1.2, react@17.0.2, react-dom@17.0.2
• Env: Firefox 93.0, node v15.5.1

Steps to reproduce

You can recreate the error in mdx-js playground: https://mdxjs.com/playground/

# Hello, world!

<!-- Hello! -->
<button>Here is a button</button>

example.mdx
  3:2  error  Unexpected character `!` (U+0021) before name, expected a character that can start a name, such as a letter, `$`, or `_` (note: to create a comment in MDX, use `{/* text */}`)  unexpected-character  micromark-extension-mdx-jsx

✖ 1 error

Expected behaviour

Parsing should succeed

Actual behaviour

Throws syntax error

[ferdinandant]

whoops, sorry the error log made it clear: Closing this now :bow:

note: to create a comment in MDX, use {/* text */}

Side note

if anyone stumbles with prettier keeps formatting your code, try {/** **/}\ (but it won't work for prettier-ignore since it will add a new newline):