Is it possible to have custom #| comments?

[etiennebacher]

Description

Hello, I'm writing an R linter (Jarl) that currently checks R files only but I'm in the middle of adding support for checking qmd/Rmd files.

This linter parses special comments such as # jarl-ignore to determine whether a particular rule violation will be reported or not. While using this comment in R code chunks works fine, I would like to be able to ignore violations in the code chunk without printing this special comment in the output (if echo: true). This is similar to a request in Air to hide fmt: skip comments in the printed output: posit-dev/air#463.

However, having a custom #| doesn't work:

```{r}
#| jarl-ignore-chunk any_is_na: reason
any(is.na(1))
```

ERROR: Validation of YAML cell metadata failed.
ERROR: In file test.qmd
(line 2, columns 4--31) property name jarl-ignore-chunk any_is_na is invalid
1: ```{r}
2: #| jarl-ignore-chunk any_is_na: reason
     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
3: any(is.na(1))

ERROR: Render failed due to invalid YAML.

I have seen quarto-dev/quarto#821, after which one might be able to do #| fmt: skip. However, it looks like this would be supported internally by Quarto and not part of a larger mechanism for custom #|.

Is it possible to support custom #|? If not, do you know any alternative to hide specific comments from the output?

[mcanouil]

By default unknown options (to knitr/Quarto) are passed on to the div as attributes.

Your issue here is not really that: comment + pipe comment is YAML, so your entry has to follow YAML: jarl-ignore-chunk any_is_na is invalid key because of the space.

What would/should work is an array:

#| jarl-ignore-chunk:
#|   - any_is_na: reason

[etiennebacher]

Aaah, I had no clue about that. That seems to work (the doc can compile, I just need to adapt my own parsing of #| jarl-ignore-chunk), thank you!