[R-pkg-devel] Is using global assignment in package tests allowed?

[Duncan Murdoch]

On 27/01/2022 10:56 a.m., James Pustejovsky wrote:
> But I am not using global variables at all in the package code (in
> /R)---only for unit testing. Is this distinction relevant? Or do I need to
> avoid global assignment even in the unit tests?

CRAN may let you do what you are doing, but as Dirk and Jeff said, it 
could come back to bite you later.  For example, you may create a 
variable named foo containing extremely valuable data, and then run your 
test.  (Tests can be run outside of R CMD check.)  If your test stomps 
on foo, you'll lose all that data.

It's worth using some trick like Dirk's to avoid this possibility.

Duncan Murdoch
> 
> On Thu, Jan 27, 2022 at 9:40 AM Dirk Eddelbuettel <edd using debian.org> wrote:
> 
>>
>> On 27 January 2022 at 07:20, Jeff Newmiller wrote:
>> | I don't know the answer to your question, but "beyond my ken" doesn't
>> sound like a very convincing reason. Mucking with any environment that
>> isn't yours is asking for trouble... the behavior you depend on today may
>> come into conflict with the code you are coordinating with when you least
>> expect it.
>>
>> Right on.
>>
>> Yes a number of packages (of mine and other people) use a different
>> approach
>> to maintain 'global state' without ... using 'global variables' (== bad).
>>
>> The trick is something like `pkgenv <- new.env()` in R/zzz.R and to then
>> also
>> set an option or two you need in .onLoad as eg  `pkgenv[["prefence"]] <-
>> "foo"`
>> which you can later test for, alter, ... at will.
>>
>> All without running afould of what `R CMD check --as-cran` may hate, all
>> the
>> while maintaining your logic flow.
>>
>> Dirk
>>
>> --
>> https://dirk.eddelbuettel.com | @eddelbuettel | edd using debian.org
>>
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-package-devel using r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-package-devel