I am trying to develop a R package that calls functions in an asynchronous way using future::future. Here is a dummy example:

library(future)
plan(multisession)

test_fun <- function(str) {
  Sys.sleep(5)
  cat(str)
}

test_future <- function() {
  future({test_fun("test")})
}

Calling the function works fine as expected

> f <- test_future()
> value(f)
# test

Nevertheless, if I put these functions in a package structure and load them (for testing) with devtools::load_all(".") I get an error upon calling the test_future function.

> devtools::load_all(".")
# ℹ Loading

> f <- test_future()
> value(f)
Error in test_fun("test") : could not find function "test_fun"

I guess its has something to do with the issue that the namespace environment is not available for the future process, but I do not understand how to come around this.

In the installed package it works fine, but I don’t understand how to test and develop using my normal workflow : implement ➡ load_all ➡ test