R/use_msrv.R

In extendr/rextendr: Call Rust Code from R using the 'extendr' Crate

#' 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)
}