Merge pull request #955 from mitchelloharawild/rng-attach

Add withr preserve seed for .onAttach random tip

DESCRIPTION

@@ -21,6 +21,7 @@ Imports:
   timeDate,
   tseries,
   urca,
+  withr,
   zoo
 Suggests:
   forecTheta,

NEWS.md

@@ -1,4 +1,5 @@
 # forecast (development version)
+  * Prevented RNG state changing when the package is attached (#954, #955).
 
 # forecast 8.22.0
   * hfitted now much faster for ARIMA models (danigiro, #949)

R/attach.R

@@ -1,5 +1,5 @@
 .onAttach <- function(...) {
-  if (!interactive() || stats::runif(1) > 0.2) return()
+  if (!interactive() || withr::with_preserve_seed(stats::runif(1)) > 0.2) return()
 
   tips <- c(
     "Use suppressPackageStartupMessages() to eliminate package startup messages.",
@@ -9,7 +9,7 @@
     "Want to stay up-to-date? Read the Hyndsight blog:\n  https://robjhyndman.com/hyndsight/",
     "Want to meet other forecasters? Join the International Institute of Forecasters:\n  http://forecasters.org/"
   )
-  tip <- sample(tips, 1)
+  tip <- withr::with_preserve_seed(sample(tips, 1))
   msg <- paste("This is forecast", packageVersion("forecast"), "\n ", tip)
   packageStartupMessage(msg)
 }