Set RNG seed for htmlwidgets IDs (r-lib#2294)

`htmlwidgets::setWidgetIdSeed()` needs to be explicitly called for this due to how `htmlwidgets:::createWidgetId()` works

NEWS.md

@@ -4,6 +4,7 @@
 * Remove redundant entries in the documentation index when multiple explicit `@usage` tags are provided (@klmr, #2302)
 * The article index now sorts vignettes and non-vignette articles alphabetically by their filename (literally, their `basename()`), by default (@jennybc, #2253).
 * Add Catalan translation (@jmaspons, #2333)
+* Set RNG seed for htmlwidgets IDs. This reduces noise in pkgdown reference HTML output when examples generate htmlwidgets (@salim-b, #2294).
 
 # pkgdown 2.0.7
 

R/build-reference.R

@@ -139,8 +139,8 @@
 #'   rapidly prototype. It is set to `FALSE` by [build_site()].
 #' @param run_dont_run Run examples that are surrounded in \\dontrun?
 #' @param examples Run examples?
-#' @param seed Seed used to initialize so that random examples are
-#'   reproducible.
+#' @param seed Seed used to initialize random number generation so that
+#'   examples are reproducible.
 #' @param devel Determines how code is loaded in order to run examples.
 #'   If `TRUE` (the default), assumes you are in a live development
 #'   environment, and loads source package with [pkgload::load_all()].
@@ -223,6 +223,9 @@ examples_env <- function(pkg, seed = 1014, devel = TRUE, envir = parent.frame())
   width <- purrr::pluck(pkg, "meta", "code", "width", .default = 80)
   withr::local_options(width = width, .local_envir = envir)
   withr::local_seed(seed)
+  if (requireNamespace("htmlwidgets", quietly = TRUE)) {
+    htmlwidgets::setWidgetIdSeed(seed)
+  }
 
   examples_env <- child_env(globalenv())
   if (file_exists(pre_path)) {

vignettes/test/widgets.Rmd

@@ -15,7 +15,7 @@ Test spacing above widget.
 
 ```{r, echo=FALSE}
 # set seed for reproducible widget id
-if (requireNamespace("htmltools", quietly = TRUE)) {
+if (requireNamespace("htmlwidgets", quietly = TRUE)) {
   htmlwidgets::setWidgetIdSeed(42)
 }