Visual editor breaks GitHub style callouts in .md files

[Aariq]

Bug description

GitHub flavored markdown uses callouts like this:

>[!TIP]
>Callout text

If you have one of these in a .md document and switch to the visual editor it changes it to:

> \[!T
> IP\] Callout text

Steps to reproduce

In RStudio or Positron, create a .md document, paste in:

>[!TIP]
>Callout text

Then switch to visual mode and back to source mode.

Actual behavior

No response

Expected behavior

I'm not sure exactly why it recognizes that spot as a line break, but if it's not a bug per se, it would be nice to have a way to exempt things like this from auto-formatting by the visual editor.

Your environment

• IDE: RStudio Version 2025.09.1+401 (2025.09.1+401)
• OS: macOS 15.6.1 (24G90)

[Aariq]

Just to clarify, you can also reproduce this with arbitrary text like [!anything]

[cderv]

I think there needs to be some precision on this. This syntax is GFM only.

>[!TIP]
>Callout text

So it won't be valid in a quarto document either, nor pandoc directly.

For example

❯ pandoc -t gfm -f markdown
>[!TIP]
>Callout text
^Z
> \[!TIP\] Callout text

So the \ are added in [!anything] markup because [ are special characters.

Can you add some context on which document you are using this syntax ?

Is this in README.md file that are written in GFM directly? And not with .qmd documents for example?

it would be nice to have a way to exempt things like this from auto-formatting by the visual editor.

When working with Quarto and pandoc, there is. And the visual editor handles it too this way.

If you want to have such GFM syntax inside a quarto doc (which could be usual for format: gfm), it needs to be included as raw block (like you would for html or latex)

```{=markdown}
>[!TIP]
>Callout text
```

This way the block won't be parsed and output as is.

The visual editor will also see it as a raw block, and it won't be rewritten.

See also for context regarding using in Quarto.

• GitHub markdown alerts being escaped quarto-cli#10815

[cscheid]

(And, as we move to using quarto-markdown, it will become easier to provide linting and error messages in these situations.)

[Aariq]

Is this in README.md file that are written in GFM directly? And not with .qmd documents for example?

Yeah, exactly, this is in a README.md I was editing in visual mode just for convenience when I noticed this. I get why the \s are added, I just didn't expect the line break. It's really not a big deal, I just though I would report it in case it was a bug.

[cscheid]

Yeah, exactly, this is in a README.md I was editing in visual mode just for convenience when I noticed this.

We should proooobably warn users when opening an .md file that this is a "no warranties" situation :) We can't promise support for all markdown dialects, and the visual editor necessarily depends on a predictable input syntax.