Dollar sign (`$`) breaks markdown syntax highlighting, completion and auto-formatting

[rmscode]

Context

No response

Bug description

Markdown that follows a dollar sign is no longer highlighted. In addition, completion of links and auto-formatting no longer works in the editor (after the $).

VS Code and VS Code Insiders
Windows 11

Related links

• Report a bug

Reproduction

reproduction.zip

Steps to reproduce

In a new profile in VS Code with only the Zensical Studio extension installed, do the following:

1. Write some markdown...
2. Include a $ somewhere in the document.
3. Write some more markdown following the $
4. Observe the noted issues

Editor

Visual Studio Code

Before submitting

• I have read and followed the bug reporting guidelines.
• I have attached links to the documentation, and possibly related issues.
• I have attached a .zip file with a minimal reproduction.
• I have read and accepted the Zensicals Terms of Service and the Zensical Studio End User License Agreement.

[squidfunk]

Thanks for reporting this. This was a tough one. Fixed in 6a9544f. We could reproduce the issue and tracked it down to an interaction with VS Code’s built-in Markdown math highlighting.

The short version is: VS Code injects its own math grammar for $...$ and $$...$$ into Markdown-like scopes. That is convenient when it works, but it is also fairly loose and can interfere with normal Markdown tokenization after a stray or unmatched dollar sign. When that happens, syntax highlighting, link completion, and editor behaviors that depend on the token stream can all degrade.

We have a few options here, and each has a trade-off:

• keep inheriting VS Code’s Markdown scope:

  • best compatibility with existing themes
  • but we also inherit its math injections and edge cases

• move to a fully separate scope:

  • full control over math handling
  • but worse theme compatibility and less reuse of existing Markdown behavior

• provide our own stricter math rules:

  • better behavior for explicit forms
  • but we still cannot reliably override all of VS Code’s built-in $ rules while staying in the Markdown scope family

For now, the practical direction is to keep theme compatibility and make our own math support stricter for the explicit forms we control, while treating the loose dollar-sign behavior as an upstream VS Code limitation. So this is understood, but the real constraint here is not just our grammar – it is how VS Code layers built-in Markdown math into editor tokenization.

We also added support for \(...\)and \[...\] syntax as supported by Python Markdown.

[squidfunk]

Here's how it looks now:

[squidfunk]

The fixes have been released as part of Zensical Studio 0.1.3. Please let us know if you encounter anything else!