Allow to skip formatting code in specific cells

[hfrick]

Description

I'm preparing slides via quarto and generally use air to format my code. For some of the code cells, I'd like to skip the formatting. I can do that with air's # fmt: skip, but then it shows up on the resulting slide. Since these are workshop slides, I'd like to avoid this since it would probably be a distraction to learners. Is there a way to skip formatting specific cells without it showing on the slide? Would something like #| format: skip be possible?

I have seen #12082 but I think it's related but different.

[mcanouil]

Formatters are currently handled on the IDE side with for instance the VSCode/Positron extension.
That's not something controlled by Quarto CLI.

Note that (minus the few known issues), you can format your code at cell level.

The repository of the extension and where the integration with formatters is done is: https://github.com/quarto-dev/quarto

[cscheid]

Context

Quarto has some precedent for doing similar things, specifically with the echo: fenced value in metadata. Consider:

---
format: html
---

## Code cell 1
```{r}
#| echo: fenced
#| error: true
# fmt: skip
cat("with echo")
```

## Code cell 2

```{r}
#| echo: false
cat("without echo")
```

output

Note how echo: fenced doesn't itself show in that output.

With this said, the code that implements this is pretty hacky and I wouldn't want to try to make it more general without rethinking it all for a bit. (In other words, we won't be able to do this for conf)

Workaround

On the other hand, you could do this removal yourself with a Lua filter that removes the comment from the CodeBlock node:

function CodeBlock(code)
  if not code.classes:includes("cell-code") then
    return nil
  end
  code.text = code.text:gsub("# fmt: skip\n", "")
  return code
end

Then, add

filters:
  - remove_fmt.lua

to your document.

Result