Running cells with `#| error: true` stops evaluation

[kylebutts]

Bug description

I am working on a quarto book and currently, I want to display some errors as part of the writing. This feature works when rendering the book. When I click "run all cells" or "run above", the code stops evaluating after an error. This means I can't easily run all the code.

It would be great if the quarto running cells takes notes of these errors and does not stop on these errors

Steps to reproduce

Reprex:

---
format: html
---

```{r}
#| error: true
mean()
```

```{r}
print("hello")
```

Click "Run all cells"

Actual behavior

No response

Expected behavior

No response

Your environment

No response

[juliasilge]

This will be pretty tough for the VS Code extension to do, because as currently designed, it does not have access to the special hash pipe comments easily. The extension creates these "virtual document" that are a regular .R or .py file containing only your regular old, say, R code. Respecting special Quarto comments for interactive code running will be a big job.

[cscheid]

@juliasilge FWIW, quarto-cli parses these out in a consistent way for all .qmd files in quarto inspect. Right now, quarto inspect is not meant for every-keystroke calling (because it invokes deno, etc etc). But if this is something we're interested in having Positron support well, quarto-cli could cache the results of quarto inspect in the .quarto directory or some other location, and then lookup would be fast.

[juliasilge]

I think we would be very interested in that kind of functionality, for example to support posit-dev/positron#3676.

[defuneste]

Similar but slightly different (should I open an other issue?).

It was discovered here: https://adv-r.hadley.nz/functions.html#on-exit (6.74) by Eamon Caddigan,

From: https://github.com/hadley/adv-r/blob/63ea8d94cdfbb13fd5dcee7d3d5e3b1e848dc7b3/Functions.Rmd#L959C1-L974C4

it is similar in quarto:

---
title: "bob"
format: html
---

```{r}
#| error = TRUE
j06 <- function(x) {
  cat("Hello\n")
  on.exit(cat("Goodbye!\n"), add = TRUE)
  
  if (x) {
    return(10)
  } else {
    stop("Error")
  }
}

j06(FALSE)
```

it will return:

Hello

Error in j06(FALSE): Error

Missing: Goodbye!

[juliasilge]

I think that is similar enough to track here as well, @defuneste. Thanks for the report!

[cderv]

@defuneste @juliasilge I do believe this is different and related to evaluate behavior:

• on.exit() not captured inside of a function r-lib/evaluate#251

The on.exit() won't be captured at all during evaluation, so won't show in quarto render, nor knitr::knit() or rmarkdown::render()

This issue here is about respecting #| error: true cell option when Running all cells.

[juliasilge]

Ah, thank you, @cderv! It looks like knitr uses the evaluate R package?

@defuneste Can you add your details to r-lib/evaluate#251 and point out how this plays out in a knitr document?

[cderv]

It looks like knitr uses the evaluate R package?

yes, all R evaluation in knitr goes through evaluate R package by default. knitr then process evaluate output. Sorry for not giving the precision, I assumed it was known.