no visible binding for global variable ‘Cloaked’

[bnsh]

Hi. I'm sure that this is a misunderstanding of mine, since I'm not really an R programmer...

I have my code here: https://gist.github.com/bnsh/3839c4eb2c6b31e32c39ec312014b2b8

#! /usr/bin/env Rscript

library(R6)

Cloaked <- R6Class("Cloaked",
  public = list(
    msg = function() {
      return(paste(
        "this code _works_, but lintr (https://github.com/jimhester/lintr) complains that",
        "external.R:6:8: warning: no visible binding for global variable ‘Cloaked’",
        "when I try to use Cloaked within a function.",
        "It's fine tho, if I use it _outside_ a function."
      ))
    }
  )
)

main <- function() {
  c <- Cloaked$new()
  c$msg()
}

main()

It works... But, lintr complains: "cloak.R:19:8: warning: no visible binding for global variable ‘Cloaked’"

Why? What do I have to do to satisfy lintr?

Thanks!

[jimhester]

There isn't really anything to do, this is the expected behavior. You can either turn off the object linter or use #nolint on that line.

[bnsh]

Thanks @jimhester ! (I didn't know if it was a real problem, and that just doing '#nolint start' / '#nolint end' would just mask the problem...)

Is this a similar issue then? (It complains about "no visible global function definition for 'cloaked'..)

 #! /usr/bin/env Rscript

cloaked <- function() {
  return(paste(
    "this code _works_, but lintr (https://github.com/jimhester/lintr)",
    "complains that external.R:13:3: warning: no visible global function",
    "definition for ‘cloaked’ when I try to use cloaked within a function.",
    "It's fine tho, if I use it _outside_ a function."
  ))
}

main <- function() {
  cloaked()
}

main()

Is that also expected behavior?

Thanks!

[jimhester]

Yes, that is expected.

[infotroph]

Can you say more about why this example is expected when #27 isn't? I don't follow whether this is a parsing limitation or if I missed a memo that using locally-defined functions is bad practice.

[jimhester]

It is expected in that it is a known issue, ideally this would be fixed, but it requires changing how the files are processed and the object linter is structured.