use_msrv()

NAMESPACE

@@ -23,6 +23,7 @@ export(to_toml)
 export(use_cran_defaults)
 export(use_crate)
 export(use_extendr)
+export(use_msrv)
 export(vendor_pkgs)
 export(write_license_note)
 importFrom(dplyr,"%>%")

R/use_msrv.R

@@ -0,0 +1,85 @@
+#' Set the minimum supported rust version (MSRV)
+#'
+#' `use_msrv()` sets the minimum supported rust version for your R package.
+#'
+#' @param version character scalar, the minimum supported Rust version.
+#' @param path character scalar, path to folder containing DESCRIPTION file.
+#' @param overwrite default `FALSE`. Overwrites the `SystemRequirements` field if already set when `TRUE`.
+#' @details
+#'
+#' The minimum supported rust version (MSRV) is determined by the
+#' `SystemRequirements` field in a package's `DESCRIPTION` file. For example, to
+#' set the MSRV to `1.67.0`, the `SystemRequirements` must have
+#' `rustc >= 1.67.0`.
+#'
+#' By default, there is no MSRV set. However, some crates have features that
+#' depend on a minimum version of Rust. As of this writing the version of Rust
+#' on CRAN's Fedora machine's is 1.69. If you require a version of Rust that is
+#' greater than that, you must set it in your DESCRIPTION file.
+#'
+#' It is also important to note that if CRAN's machines do not meet the
+#' specified MSRV, they will not be able to build a binary of your package. As a
+#' consequence, if users try to install the package they will be required to
+#' have Rust installed as well.
+#'
+#' To determine the MSRV of your R package, we recommend installing the
+#' `cargo-msrv` cli. You can do so by running `cargo install cargo-msrv`. To
+#' determine your MSRV, set your working directory to `src/rust` then run
+#' `cargo msrv`. Note that this may take a while.
+#'
+#' For more details, please see
+#' [cargo-msrv](https://github.com/foresterre/cargo-msrv).
+#'
+#' @return `version`
+#' @export
+#'
+#' @examples
+#' \dontrun{
+#' use_msrv("1.67.1")
+#' }
+#'
+use_msrv <- function(version, path = ".", overwrite = FALSE) {
+  check_string(version, class = "rextendr_error")
+  check_string(path, class = "rextendr_error")
+  check_bool(overwrite, class = "rextendr_error")
+
+  msrv_call <- rlang::caller_call()
+  version <- tryCatch(numeric_version(version), error = function(e) {
+    cli::cli_abort(
+      "Invalid version provided",
+      class = "rextendr_error",
+      call = msrv_call
+    )
+  })
+
+  desc_path <- rprojroot::find_package_root_file("DESCRIPTION", path = path)
+
+  if (!file.exists(desc_path)) {
+    cli::cli_abort(
+      "{.arg path} ({.path {path}}) does not contain a DESCRIPTION",
+      class = "rextendr_error"
+    )
+  }
+
+  cur <- paste("Cargo (Rust's package manager), rustc", paste(">=", version))
+
+  prev <- desc::desc_get("SystemRequirements", file = desc_path)[[1]]
+  prev <- stringi::stri_trim_both(prev)
+  prev_is_default <- identical(prev, "Cargo (Rust's package manager), rustc")
+
+  # if it isn't set update the description or if overwrite is true
+  if (is.na(prev) || overwrite || prev_is_default) {
+    update_description("SystemRequirements", cur, desc_path = desc_path)
+  } else if (!identical(cur, prev) && !overwrite) {
+    cli::cli_ul(
+      c(
+        "The SystemRequirements field in the {.file DESCRIPTION} file is
+        already set.",
+        "Please update it manually if needed.",
+        "{.code SystemRequirements: {cur}}"
+      )
+    )
+  }
+
+  invisible(version)
+}

_pkgdown.yml

@@ -22,6 +22,7 @@ reference:
   - write_license_note
   - clean
   - cran
+  - use_msrv
 
 - title: Various utility functions
   contents:

tests/testthat/test-use_msrv.R

@@ -0,0 +1,18 @@
+test_that("use_msrv() modifies the MSRV in the DESCRIPTION", {
+  skip_if_not_installed("usethis")
+
+  path <- local_package("testpkg")
+
+  # capture setup messages
+  withr::local_options(usethis.quiet = FALSE)
+
+  use_extendr(path, quiet = TRUE)
+  use_msrv("1.70", path)
+
+  d <- desc::desc("DESCRIPTION")
+
+  expect_identical(
+    "Cargo (Rust's package manager), rustc >= 1.70",
+    d$get_field("SystemRequirements")
+  )
+})