From 49198d486c66ba3efff95b00b74722db14836610 Mon Sep 17 00:00:00 2001
From: Salim B <git@salim.space>
Date: Mon, 11 Mar 2024 17:05:51 +0100
Subject: [PATCH] Fix setting `seed` in `build_reference()` (#2355)

And test that it works
---
 DESCRIPTION                                 |  1 +
 NEWS.md                                     |  1 +
 R/build-reference.R                         |  2 +-
 tests/testthat/_snaps/build-reference.md    |  8 ++++++++
 tests/testthat/assets/reference/DESCRIPTION |  2 +-
 tests/testthat/assets/reference/R/funs.R    |  6 ++++++
 tests/testthat/assets/reference/man/f.Rd    | 15 +++++++++++++++
 tests/testthat/test-build-reference.R       | 13 +++++++++++++
 8 files changed, 46 insertions(+), 2 deletions(-)
 create mode 100644 tests/testthat/assets/reference/man/f.Rd

diff --git a/DESCRIPTION b/DESCRIPTION
index ae63aff587..0d1d1e36b5 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -55,6 +55,7 @@ Suggests:
     rsconnect,
     rstudioapi,
     rticles,
+    rvest,
     sass,
     testthat (>= 3.1.3),
     tools
diff --git a/NEWS.md b/NEWS.md
index c0b32ce0c6..130e633951 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -11,6 +11,7 @@
 * 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).
 * Fix BS5 navbar template to get `navbar.type: dark` to work with bslib 0.6+ / Bootstrap 5.3+ (@tanho63, #2388)
+* Fix setting `seed` in `build_reference()`. The seed was reset too early, before. (@salim-b, #2355)
 * Translates citation sections (@eliocamp, #2410).
 * Topic names that conflict with selector functions can now be listed as references in `_pkgdown.yml` (@dmurdoch, #2397).
 
diff --git a/R/build-reference.R b/R/build-reference.R
index 3ebb37c222..5d915fbc71 100644
--- a/R/build-reference.R
+++ b/R/build-reference.R
@@ -227,7 +227,7 @@ examples_env <- function(pkg, seed = 1014, devel = TRUE, envir = parent.frame())
   withr::local_dir(path(pkg$dst_path, "reference"), .local_envir = envir)
   width <- purrr::pluck(pkg, "meta", "code", "width", .default = 80)
   withr::local_options(width = width, .local_envir = envir)
-  withr::local_seed(seed)
+  withr::local_seed(seed, .local_envir = envir)
   if (requireNamespace("htmlwidgets", quietly = TRUE)) {
     htmlwidgets::setWidgetIdSeed(seed)
   }
diff --git a/tests/testthat/_snaps/build-reference.md b/tests/testthat/_snaps/build-reference.md
index 31f9b6a921..b7f436bd5a 100644
--- a/tests/testthat/_snaps/build-reference.md
+++ b/tests/testthat/_snaps/build-reference.md
@@ -44,3 +44,11 @@
       Reading man/a.Rd
       Writing reference/a.html
 
+# examples are reproducible by default, i.e. 'seed' is respected
+
+    Code
+      cat(examples)
+    Output
+      testpackage:::f()
+      #> [1] 0.080750138 0.834333037 0.600760886 0.157208442 0.007399441
+
diff --git a/tests/testthat/assets/reference/DESCRIPTION b/tests/testthat/assets/reference/DESCRIPTION
index 8e969ae067..564f9eab77 100644
--- a/tests/testthat/assets/reference/DESCRIPTION
+++ b/tests/testthat/assets/reference/DESCRIPTION
@@ -3,4 +3,4 @@ Version: 1.0.0
 Title: A test package
 Description: A test package
 Authors@R: person("Hadley Wickham")
-RoxygenNote: 7.2.0
+RoxygenNote: 7.2.3
diff --git a/tests/testthat/assets/reference/R/funs.R b/tests/testthat/assets/reference/R/funs.R
index a537ae407f..b5ead798d2 100644
--- a/tests/testthat/assets/reference/R/funs.R
+++ b/tests/testthat/assets/reference/R/funs.R
@@ -21,3 +21,9 @@ c <- function() {}
 #' E
 #' @name e
 NULL
+
+#' F
+#' @keywords internal
+#' @examples
+#' testpackage:::f()
+f <- function() {runif(5L)}
diff --git a/tests/testthat/assets/reference/man/f.Rd b/tests/testthat/assets/reference/man/f.Rd
new file mode 100644
index 0000000000..f093faac2e
--- /dev/null
+++ b/tests/testthat/assets/reference/man/f.Rd
@@ -0,0 +1,15 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/funs.R
+\name{f}
+\alias{f}
+\title{F}
+\usage{
+f()
+}
+\description{
+F
+}
+\examples{
+testpackage:::f()
+}
+\keyword{internal}
diff --git a/tests/testthat/test-build-reference.R b/tests/testthat/test-build-reference.R
index 43356f1368..1366c8ae1f 100644
--- a/tests/testthat/test-build-reference.R
+++ b/tests/testthat/test-build-reference.R
@@ -94,6 +94,19 @@ test_that("pkgdown html dependencies are suppressed from examples in references"
   expect_length(bs_css_href, 1)
 })
 
+test_that("examples are reproducible by default, i.e. 'seed' is respected", {
+  pkg <- local_pkgdown_site(test_path("assets/reference"))
+  suppressMessages(build_reference(pkg, topics = "f"))
+
+  examples <- xml2::read_html(file.path(pkg$dst_path, "reference", "f.html")) %>%
+    rvest::html_node("div#ref-examples div.sourceCode") %>%
+    rvest::html_text() %>%
+    # replace line feeds with whitespace to make output platform independent
+    gsub("\r", "", .)
+
+  expect_snapshot(cat(examples))
+})
+
 test_that("get_rdname handles edge cases", {
   expect_equal(get_rdname(list(file_in = "foo..Rd")), "foo.")
   expect_equal(get_rdname(list(file_in = "foo.rd")), "foo")