Uninformative error when leaving an empty @param

[pierrecamilleri]

Hi,
Leaving an empty #' @param in a roxygen comment leads to an error with no information at all to identify the problem:
Error in FUN(X[[i]], ...) : index out of bound

I believe it could be useful to specify in which comment the error occurs in such situations.

[tbates]

Can't replicate in packageVersion("devtools") ‘2.0.2’. Help builds fine, and issues a helpful warning about @param needing a value.

Here's a repro file (which should have be provided with the original issue...) Need to save it as .R

#' Fn with hanging @@param
#' @param
#' @export
#' @family Data Functions
checkMe <- function() {}

I get

Warning: @param [/Users/tim/bin/umx/R/hang_param.R#3]: requires a value

hang_param.txt

[pierrecamilleri]

which should have be provided with the original issue...

Hum, yes, please accept my apologies for that.

Here is one: with an empty line after the @param line.

#' Fn with hanging @@param
#' @param
#'
#' @export
#' @family Data Functions
checkMe <- function() {}

I have put that function in the R directory of an empty "test" package and have run "devtools::document()", and get the aforementioned error (in French).

I indeed get no error and the proper warning with same procedure but without the additional empty line.
Devtools package version is 2.0.2 as well.

[tbates]

A nice user message for this error would require catching white space after param (including a new line), and trimming it out. Then would be treated as the no-value-provided case. (or else require that the value be on the same line as @param - but that would break this, which currently works:

#' param test
#'
#' @description
#' param on new line
#' @param
#' x here I am
#' @return - matrix
#' @export
tmp <- function(x) {
	matrix(1:4, nrow = 2)
}

[hadley]

Minimal reprex:

library(roxygen2)
roc_proc_text(rd_roclet(), "
  #' Title
  #' @param
  #'
  #' @export
  foo <- function() {}"
)
#> Error in FUN(X[[i]], ...): subscript out of bounds

^{Created on 2019-07-25 by the reprex package (v0.3.0)}