BUG: findGlobals(local({ f <- function(x) x; x })) fails to identify 'x' as a global variable

[HenrikBengtsson]

Despite fixing the following in globals 0.14.0 (Issue #69):

> globals::findGlobals({ f <- function(x) x; x }, substitute = TRUE)
[1] "{"  "<-" "x"

it fails when wrapped inside other calls:

> globals::findGlobals(local({ f <- function(x) x; x }), substitute = TRUE)
[1] "local" "{"     "<-"

> globals::findGlobals(tryCatch({ f <- function(x) x; x }), substitute = TRUE)
[1] "tryCatch" "{"        "<-"

> globals::findGlobals(lapply(1:2, function(idx) { f <- function(x) x; x }), substitute = TRUE)
[1] "lapply" ":"      "{"      "<-" 

Because of this, future map-reduce calls like:

> future::plan("cluster", workers = 1L)
> x <- 42

> y <- future.apply::future_lapply(1:2, function(idx) { f <- function(x) x; x })
Error in ...future.FUN(...future.X_jj, ...) : object 'x' not found

> y <- furrr::future_map(1:2, function(idx) { f <- function(x) x; x })
Error in ...furrr_fn(...) : object 'x' not found

> library(foreach)
> doFuture::registerDoFuture()
> y <- foreach(idx=1:2) %dopar% { f <- function(x) x; x }
Error in { : task 1 failed - "object 'x' not found"

The latter is adapted from futureverse/doFuture#46

[HenrikBengtsson]

A slightly smaller version of this problem is:

> globals::findGlobals(local({ function(x) x; x }), substitute = TRUE)
[1] "local" "{"

We also note that ordering matters:

> globals::findGlobals(local({ x; function(x) x }), substitute = TRUE)
[1] "local" "{"     "x"