Unable to pass NULL as target value

[odaniel1]

Prework

• Read and abide by drake's code of conduct.
• Search for duplicates among the existing issues, both open and closed.
• [] I am reasonably sure this is a genuine bug in drake and most likely not a user error. (If you run into an error and do not know the cause, please submit a "Trouble" issue instead.)
• Be considerate of the maintainer's time and make it as easy as possible to troubleshoot any problems you identify. Read here and here to learn about minimal reproducible examples. Format your code according to the tidyverse style guide to make it easier for others to read.

Description

Passing NULL directly to drake as a target value returns a safe_deparse error.

Reproducible example

library(drake)
plan <- drake_plan(a = NULL)
make(plan)
#> Error in safe_deparse(x, backtick = TRUE): argument "x" is missing, with no default

Expected result

drake can handle NULL when returned as a value from a function; I had anticipated the same behaviour as the below:

library(drake)
f <- function(){return(NULL)}
plan <- drake_plan(a = f())
make(plan)
#> ▶ target a

Session info

#> ─ Session info ───────────────────────────────────────────────────────────────
#>  setting  value                       
#>  version  R version 3.6.3 (2020-02-29)
#>  os       Ubuntu 18.04.4 LTS          
#>  system   x86_64, linux-gnu           
#>  ui       X11                         
#>  language en_GB:en                    
#>  collate  en_GB.UTF-8                 
#>  ctype    en_GB.UTF-8              
#>  date     2020-07-22 

[odaniel1]

I tried to re-tag as trouble but can't edit the label myself (I don't think!). Likely should be tagged as that instead - sorry!

[wlandau]

Thanks, should be fixed now.