Never lower an R version requirement in use_data() (#2083)

* Introduce failing test

* Use NA when there's no minimum version stated for R

* Never lower minimum R version via use_data()

* Don't attempt to pass NA to numeric_version()

Apparently this works only in R >= 4.2

R/data.R

@@ -44,11 +44,13 @@ use_data <- function(...,
 
   objs <- get_objs_from_dots(dots(...))
 
-  if (version < 3) {
-    use_dependency("R", "depends", "2.10")
-  } else {
-    use_dependency("R", "depends", "3.5")
+  original_minimum_r_version <- pkg_minimum_r_version()
+  serialization_minimum_r_version <- if (version < 3) "2.10" else "3.5"
+  if (is.na(original_minimum_r_version) ||
+      original_minimum_r_version < serialization_minimum_r_version) {
+        use_dependency("R", "depends", serialization_minimum_r_version)
   }
+
   if (internal) {
     use_directory("R")
     paths <- path("R", "sysdata.rda")

R/release.R

@@ -534,10 +534,11 @@ author_has_rstudio_email <- function() {
 pkg_minimum_r_version <- function() {
   deps <- proj_desc()$get_deps()
   r_dep <- deps[deps$package == "R" & deps$type == "Depends", "version"]
-  if (length(r_dep) == 0) {
-    return(numeric_version("0"))
+  if (length(r_dep) > 0) {
+    numeric_version(gsub("[^0-9.]", "", r_dep))
+  } else {
+    NA_character_
   }
-  numeric_version(gsub("[^0-9.]", "", r_dep))
 }
 
 # Borrowed from pak, but modified also retain user's non-cran repos:

R/upkeep.R

@@ -243,14 +243,15 @@ tidy_upkeep_checklist <- function(last_upkeep = last_upkeep_year(),
     )
   }
 
+  minimum_r_version <- pkg_minimum_r_version()
   bullets <- c(
     bullets,
     "### To finish",
     "",
     todo("`usethis::use_mit_license()`", grepl("MIT", desc$get_field("License"))),
     todo(
       '`usethis::use_package("R", "Depends", "{tidy_minimum_r_version()}")`',
-      tidy_minimum_r_version() > pkg_minimum_r_version()
+      is.na(minimum_r_version) || tidy_minimum_r_version() > minimum_r_version
     ),
     todo("`usethis::use_tidy_description()`"),
     todo("`usethis::use_tidy_github_actions()`"),

tests/testthat/test-data.R

@@ -95,3 +95,14 @@ test_that("use_data_raw() does setup", {
 
   expect_true(is_build_ignored("^data-raw$"))
 })
+
+test_that("use_data() does not decrease minimum version of R itself", {
+  create_local_package()
+
+  use_package("R", "depends", "4.1")
+  original_minimum_r_version <- pkg_minimum_r_version()
+
+  use_data(letters)
+
+  expect_true(pkg_minimum_r_version() >= original_minimum_r_version)
+})