purrr to package whitelist

[medewitt]

When using data.table in an Rmd document and then trying to use purrr::map to apply the rmarkdown::render function the Rmd is nolonger data.table aware and rendering fails.

More details in https://github.com/tidyverse/purrr/issues/789#issue-682118090.

Minimal reproducible example

Reprex:

• an Rmd document
• an R script that renders the Rmd

---Rmarkdown contents saved as test.Rmd---

---
title: "Untitled"
output: html_document
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
```

```{r}
library(dplyr)
library(data.table)
.datatable.aware = TRUE

dat <- data.table(x = rnorm(100),
                  y = rnorm(100),
                  grouper = sample(letters, 100, replace = TRUE))

dat[ ,z:=x+y]

```

---

In a separate script I do the following:

x <- "test.Rmd"

# Fails---
purrr::map(x, rmarkdown::render)
#Quitting from lines 13-23 (dattableconflict.Rmd) 
#Error: `:=` can only be used within a quasiquoted argument

# Sucessful--
rmarkdown::render(x)

I tried all of the solutions proposed in this initial post. This behaviour does not seem to be isolated to :=, but also some of the NSE within data.table as well. For instance:

---
title: "Untitled"
output: html_document
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
```

```{r}
library(dplyr)
library(data.table)
.datatable.aware = TRUE

dat <- data.table(x = rnorm(100),
                  y = rnorm(100),
                  grouper = sample(letters, 100, replace = TRUE),
                  date = seq.Date(Sys.Date(), length.out = 100, by = 1))

dat[,.SD[which.min(date)], by = grouper]

```

With:

x <- "test.Rmd"

purrr::map(x, rmarkdown::render)
# Error in which.min(date) : 
#  cannot coerce type 'closure' to vector of type 'double'

The solution at this point from the purrr side is to use anonymous function, but maybe adding purrr to the whitelist would help other users.

Output of sessionInfo()

R version 3.6.1 (2019-07-05)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 17763)

Matrix products: default

locale:
[1] LC_COLLATE=English_United States.1252 
[2] LC_CTYPE=English_United States.1252   
[3] LC_MONETARY=English_United States.1252
[4] LC_NUMERIC=C                          
[5] LC_TIME=English_United States.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets 
[6] methods   base     

loaded via a namespace (and not attached):
[1] compiler_3.6.1 tools_3.6.1  

[medewitt]

closing issue as purrr development team will propose solution