r - "Could not find function" in Roxygen examples during CMD check

Question

I'm running a CMD check on a package in RStudio, part of which analyses the @examples in the inline Roxygen documentation.

I'm getting this error:

checking examples ... ERROR
Running examples in ‘packagename-Ex.R’ failed
The error most likely occurred in:

> base::assign(".ptime", proc.time(), pos = "CheckExEnv")
> ### Name: checkDate
> ### Title: Ensure that a date string is a valid date
> ### Aliases: checkDate
> 
> ### ** Examples
> 
> checkDate("2017-05-06")
Error: could not find function "checkDate"

Within my .R file, the documentation is defined as:

#' Ensure that a date string is a valid date
#'
#' @param dateString A string (eg. "2017-12-04").
#' @return TRUE or FALSE (and a warning if FALSE).
#' @examples
#' checkDate("2017-05-06")
#' checkDate("2017-05-40")

I am using devtools 1.13.2 and roxygen2 6.0.1, both of which I believe to be up-to-date at time of posting.

I have other packages using this same devtools/roxygen2 combination but have never before seen it fail to find a function name in @examples within its scope.

Someone else seems to have experienced something similar as an update to this question, but I can't see that anyone says how to fix it.

Answer 1

My guess is that you need to #' @export the function in the Roxygen comment, otherwise the function is not exported to the namespace of the package and it cannot be found.