MDX with frontmatter reports errors on wrong line

[nmattia]

Astro Info

Astro                    v4.13.4
Node                     v20.9.0
System                   macOS (x64)
Package Manager          npm
Output                   static
Adapter                  none
Integrations             @astrojs/sitemap
                         @astrojs/mdx

If this issue only occurs in one browser, which browser is a problem?

No response

Describe the Bug

When an .mdx page with an error uses a frontmatter, the error is reported on the wrong line (frontmatter is not included):

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 */})

  ...

blog/hello.mdx:2:2

---
title: "hello"
 ^
og_image: /images/hello.jpg
description: "hello"
pubDate: 2024-08-13
draft: true
tags:
  - "hello1"
  - "hello2"
---

<!-- hello! I cause an issue -->

What's the expected result?

Error should be reported on the actual problematic line (12)

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 */})

  ...

blog/hello.mdx:12:2

---
title: "hello"
og_image: /images/hello.jpg
description: "hello"
pubDate: 2024-08-13
draft: true
tags:
  - "hello1"
  - "hello2"
---

<!-- hello! I cause an issue -->
 ^

Link to Minimal Reproducible Example

https://stackblitz.com/github/withastro/astro/tree/latest/examples/basics?file=astro.config.mjs

Participation

• I am willing to submit a pull request for this issue.

[nmattia]

@bluwy thanks for the quick fix!