code-fold html code blocks

[JosiahParry]

Description

From what I can tell, it is not possible to provide code folding for generic code chunks in quarto. Only code that is actually evaluated / is defined with a language chunk like so {r} or {python} can actually be folded.

Ideally I'd like to be able to have something like so:

## Exercise

- Create a new Rust crate called `intro-to-rust`

```bash
#| code-fold: true
#| code-summary: Show solution
cargo new intro-to-rust
```

It creates the following:

A work around is to write

```{r eval=FALSE}
#| code-fold: true
#| code-summary: Show solution
cargo new intro-to-rust
```

but then you lose syntax highlighting

[mcanouil]

Why do you change the language?
You should avoid mixing YAML an R inline syntax for code cells options. This is true also true in RMarkdown.

---
format: html
engine: knitr
---

```{bash}
#| eval: false
#| code-fold: true
#| code-summary: Show solution
cargo new intro-to-rust
```

[mcanouil]

There is a community-based extension to add details block anywhere: https://github.com/jmgirard/details

[JosiahParry]

Why do you change the language?

Because shell and rust are different languages than R or Python and I would like to have code bocks to show that.

This doesn't work:

```{rust}
#| code-fold: true
fn main() {
    println!("Hello, world!");
}
```

nor does

```{rust}
fn main() {
    println!("Hello, world!");
}
```

[mcanouil]

I meant, the knitr engine "supports" a lot of languages, so you don't need to change to a bad/wrong one.

---
format: html
engine: knitr
---

```{rust}
#| eval: false
#| code-fold: true
#| code-summary: Show solution
fn main() {
    println!("Hello, world!");
}
```

[mcanouil]

Note that there is an issue already opened:

• code-fold for non executable code #4693