changes for RNG consistency in #389 (#390)

* changes for RNG consistency in #389

* refactor RNG kind fixes

DESCRIPTION

@@ -37,6 +37,7 @@ Imports:
     tibble (>= 3.1.0),
     tidyr,
     vctrs (>= 0.3.0),
+    withr,
     workflows (>= 0.2.2),
     yardstick (>= 0.0.7)
 Suggests: 

NEWS.md

@@ -1,5 +1,7 @@
 # tune (development version)
 
+* When using `load_pkgs()`, packages that use random numbers on start-up do not affect the state of the RNG. We also added more control of the RNGkind to make it consistent with the user's previous value (#389). 
+
 # tune 0.1.5
 
 * Fixed a bug where the resampled confusion matrix is transposed when `conf_mat_resamped(tidy = FALSE)` (#372)

R/grid_code_paths.R

@@ -125,7 +125,11 @@ tune_grid_loop_iter <- function(iteration,
 
   # After package loading to avoid potential package RNG manipulation
   if (!is.null(seed)) {
+    # `assign()`-ing the random seed alters the `kind` type to L'Ecuyer-CMRG,
+    # so we have to ensure it is restored on exit
+    old_kind <- RNGkind()[[1]]
     assign(".Random.seed", seed, envir = globalenv())
+    on.exit(RNGkind(kind = old_kind), add = TRUE)
   }
 
   control_parsnip <- parsnip::control_parsnip(verbosity = 0, catch = TRUE)

R/load_ns.R

@@ -13,7 +13,7 @@ load_pkgs <- function(x, ...) {
 
 #' @export
 load_pkgs.character <- function(x, ...) {
-  load_namespace(x)
+  withr::with_preserve_seed(load_namespace(x))
 }
 
 #' @export

inst/WORDLIST

@@ -30,6 +30,7 @@ preprocessed
 preprocessor
 reprex
 RBF
+RNGkind
 stanford
 tibble
 tibbles

tests/testthat/test-extract.R

@@ -28,6 +28,7 @@ test_that('tune recipe only', {
   extr_1_1 <- function(x) {
     extract_recipe(x) %>% tidy(number = 2)
   }
+  before_kind <- RNGkind()[[1]]
   expect_error(
     res_1_1 <-
       workflow() %>%
@@ -36,6 +37,8 @@ test_that('tune recipe only', {
       tune_grid(resamples = mt_folds, control = control_grid(extract = extr_1_1)),
     NA
   )
+  after_kind <- RNGkind()[[1]]
+  expect_equal(before_kind, after_kind)
   expect_error(extract_1_1 <- dplyr::bind_rows(res_1_1$.extracts), NA)
 
   expect_true(all(names(extract_1_1) == c("num_comp", ".extracts", ".config")))