feat: System checks on systemRequirements (#379)

* feat: modifies `use_cran_defaults()` to perform system checks on cargo and rustc versions for CRAN compliance.

* docs: add missing `rust_source.Rd`, `use_crate.Rd` and `write_license_note.Rd`, and update NAMESPACE.

* chore: Bump dev version and update NEWS

* feat: Add tools directory and msrv.R template for CRAN compliance

* tests: Update snapshots for `use_cran_defaults()` and `use_extendr()`

* tests: update tests

* docs: Add `use_crate` to package development reference

* Update snapshots

* Update NEWS.md

---------

Co-authored-by: Josiah Parry <josiah.parry@gmail.com>

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: rextendr
 Title: Call Rust Code from R using the 'extendr' Crate
-Version: 0.3.1.9000
+Version: 0.3.1.9001
 Authors@R: 
     c(person(given = "Claus O.",
              family = "Wilke",
@@ -69,6 +69,6 @@ Config/testthat/edition: 3
 Config/testthat/parallel: true
 Encoding: UTF-8
 Roxygen: list(markdown = TRUE)
-RoxygenNote: 7.3.1
+RoxygenNote: 7.3.2
 SystemRequirements: Rust 'cargo'; the crate 'libR-sys' must compile
     without error

NAMESPACE

@@ -21,6 +21,7 @@ export(rust_sitrep)
 export(rust_source)
 export(to_toml)
 export(use_cran_defaults)
+export(use_crate)
 export(use_extendr)
 export(vendor_pkgs)
 export(write_license_note)

NEWS.md

@@ -14,6 +14,7 @@
 * Removed `use_try_from` as an option in `rust_function`, and added `use_rng` (#354)
 * Added `use_crate()` function to make adding dependencies to Cargo.toml easier within R, similar to `usethis::use_package()` (#361)
 * Fixed an issue in `rust_source()` family of functions that prevented usage of `r#` escape sequences in Rust function names (#374)
+* `use_cran_defaults()` now checks the `SystemRequirements` field in the `DESCRIPTION` file for cargo and rustc. It will display installation instructions if either is missing or provide the minimum required version if the installed version is outdated.
 
 # rextend 0.3.1
 

R/cran-compliance.R

@@ -5,7 +5,7 @@
 #' @details
 #'
 #' `use_cran_defaults()` modifies an existing package to provide CRAN complaint
-#' settings and files. It creates `configure` and `configure.win` files as well as
+#' settings and files. It creates `tools/msrv.R`, `configure` and `configure.win` files as well as
 #'  modifies `Makevars` and `Makevars.win` to use required CRAN settings.
 #'
 #' `vendor_pkgs()` is used to package the dependencies as required by CRAN.
@@ -52,6 +52,19 @@ use_cran_defaults <- function(path = ".", quiet = FALSE, overwrite = NULL, lib_n
     )
   }
 
+  # create tools directory if it does not exist
+  if (!dir.exists("tools")) {
+    dir.create("tools")
+  }
+
+  # add msrv.R template
+  use_rextendr_template(
+    "cran/msrv.R",
+    save_as = file.path("tools", "msrv.R"),
+    quiet = quiet,
+    overwrite = overwrite
+  )
+
   # add configure and configure.win templates
   use_rextendr_template(
     "cran/configure",

_pkgdown.yml

@@ -16,6 +16,7 @@ reference:
 - title: Package development
   contents:
   - use_extendr
+  - use_crate
   - document
   - register_extendr
   - write_license_note

inst/templates/cran/configure

@@ -1,21 +1,3 @@
 #!/usr/bin/env sh
-
-# https://github.com/eitsupi/prqlr/blob/main/configure
-export PATH="$PATH:$HOME/.cargo/bin"
-
-if [ ! "$(command -v cargo)" ]; then
-    echo "----------------------- [RUST NOT FOUND]---------------------------"
-    echo "The 'cargo' command was not found on the PATH. Please install rustc"
-    echo "from: https://www.rust-lang.org/tools/install"
-    echo ""
-    echo "Alternatively, you may install cargo from your OS package manager:"
-    echo " - Debian/Ubuntu: apt-get install cargo"
-    echo " - Fedora/CentOS: dnf install cargo"
-    echo " - macOS: brew install rustc"
-    echo "-------------------------------------------------------------------"
-    echo ""
-    exit 1
-fi
-
-exit 0
-
+: "${R_HOME=`R RHOME`}"
+"${R_HOME}/bin/Rscript" tools/msrv.R 

inst/templates/cran/configure.win

@@ -1,15 +1,2 @@
-#!/bin/sh
-
-# https://github.com/eitsupi/prqlr/blob/main/configure.win
-export PATH="$PATH:$HOME/.cargo/bin"
-
-if [ ! "$(command -v cargo)" ]; then
-    echo "----------------------- [RUST NOT FOUND]---------------------------"
-    echo "The 'cargo' command was not found on the PATH. Please install rustc"
-    echo "from: https://www.rust-lang.org/tools/install"
-    echo "-------------------------------------------------------------------"
-    echo ""
-    exit 1
-fi
-
-exit 0
+#!/usr/bin/env sh
+"${R_HOME}/bin${R_ARCH_BIN}/Rscript.exe" tools/msrv.R

inst/templates/cran/msrv.R

@@ -0,0 +1,116 @@
+# read the DESCRIPTION file
+desc <- read.dcf("DESCRIPTION")
+
+if (!"SystemRequirements" %in% colnames(desc)) {
+  fmt <- c(
+    "`SystemRequirements` not found in `DESCRIPTION`.",
+    "Please specify `SystemRequirements: Cargo (Rust's package manager), rustc`"
+  )
+  stop(paste(fmt, collapse = "\n"))
+}
+
+# extract system requirements
+sysreqs <- desc[, "SystemRequirements"]
+
+# check that cargo and rustc is found
+if (!grepl("cargo", sysreqs, ignore.case = TRUE)) {
+  stop("You must specify `Cargo (Rust's package manager)` in your `SystemRequirements`")
+}
+
+if (!grepl("rustc", sysreqs, ignore.case = TRUE)) {
+  stop("You must specify `Cargo (Rust's package manager), rustc` in your `SystemRequirements`")
+}
+
+# split into parts
+parts <- strsplit(sysreqs, ", ")[[1]]
+
+# identify which is the rustc
+rustc_ver <- parts[grepl("rustc", parts)]
+
+# perform checks for the presence of rustc and cargo on the OS
+no_cargo_msg <- c(
+  "----------------------- [CARGO NOT FOUND]--------------------------",
+  "The 'cargo' command was not found on the PATH. Please install Cargo",
+  "from: https://www.rust-lang.org/tools/install",
+  "",
+  "Alternatively, you may install Cargo from your OS package manager:",
+  " - Debian/Ubuntu: apt-get install cargo",
+  " - Fedora/CentOS: dnf install cargo",
+  " - macOS: brew install rustc",
+  "-------------------------------------------------------------------"
+)
+
+no_rustc_msg <- c(
+  "----------------------- [RUST NOT FOUND]---------------------------",
+  "The 'rustc' compiler was not found on the PATH. Please install",
+  paste(rustc_ver, "or higher from:"),
+  "https://www.rust-lang.org/tools/install",
+  "",
+  "Alternatively, you may install Rust from your OS package manager:",
+  " - Debian/Ubuntu: apt-get install rustc",
+  " - Fedora/CentOS: dnf install rustc",
+  " - macOS: brew install rustc",
+  "-------------------------------------------------------------------"
+)
+
+# Add {user}/.cargo/bin to path before checking
+new_path <- paste0(
+  Sys.getenv("PATH"),
+  ":",
+  paste0(Sys.getenv("HOME"), "/.cargo/bin")
+)
+
+# set the path with the new path
+Sys.setenv("PATH" = new_path)
+
+# check for rustc installation
+rustc_version <- tryCatch(
+  system("rustc --version", intern = TRUE),
+  error = function(e) {
+    stop(paste(no_rustc_msg, collapse = "\n"))
+  }
+)
+
+# check for cargo installation
+cargo_version <- tryCatch(
+  system("cargo --version", intern = TRUE),
+  error = function(e) {
+    stop(paste(no_cargo_msg, collapse = "\n"))
+  }
+)
+
+# helper function to extract versions
+extract_semver <- function(ver) {
+  if (grepl("\\d+\\.\\d+(\\.\\d+)?", ver)) {
+    sub(".*?(\\d+\\.\\d+(\\.\\d+)?).*", "\\1", ver)
+  } else {
+    NA
+  }
+}
+
+# get the MSRV
+msrv <- extract_semver(rustc_ver)
+
+# extract current version
+current_rust_version <- extract_semver(rustc_version)
+
+# perform check
+if (!is.na(msrv)) {
+  # -1 when current version is later
+  # 0 when they are the same
+  # 1 when MSRV is newer than current
+  is_msrv <- utils::compareVersion(msrv, current_rust_version)
+  if (is_msrv == 1) {
+    fmt <- paste0(
+      "\n------------------ [UNSUPPORTED RUST VERSION]------------------\n",
+      "- Minimum supported Rust version is %s.\n",
+      "- Installed Rust version is %s.\n",
+      "---------------------------------------------------------------"
+    )
+    stop(sprintf(fmt, msrv, current_rust_version))
+  }
+}
+
+# print the versions
+versions_fmt <- "Using %s\nUsing %s"
+message(sprintf(versions_fmt, cargo_version, rustc_version))