R/check_package.R

In NorwegianVeterinaryInstitute/NVIcheckmate: Extension of checkmate with argument checking adapted for NVIverse

#' @title Check if an object is an installed or attached package
#' @description Check if a package is installed and if it is installed, check if the version is equal
#'     to or higher than the required version or check if a package is attached.
#'
#' @templateVar fn package
#' @template x
#' @param version \[character(1)\]\cr
#'     The required version of the installed package. May be \code{NULL}.
#' @param type \[character(1)\]\cr
#'  Type of formal check(s) to perform on the package.
#'  \describe{
#'  \item{installed:}{Checks if \code{x} is installed.}
#'  \item{attached:}{Checks if \code{x} is attached.}
#'  }

#' @template checker
#' @export
#' @examples
#' # returns TRUE i.e. no error message
#' check_package(x = "checkmate", version = "2.0.0", type = "installed")
#'
#' # returns an error message
#' check_package(x = "nopackage", type = "installed")
#' check_package(x = "nopackage", type = "attached")
check_package <- function(x, version = NULL, type = "installed") {
  # ARGUMENT CHECKING ----
  # Object to store check-results
  checks <- checkmate::makeAssertCollection()

  # Perform checks
  checkmate::assert_character(x = x, len = 1, min.char = 2, add = checks)
  checkmate::assert_character(x = version, len = 1, null.ok = TRUE, add = checks)
  checkmate::assert_choice(x = type, choices = c("attached", "installed"), add = checks)

  # Report check-results
  checkmate::reportAssertions(checks)

  # PERFORM CHECK
  if (type == "installed") {
    # if the package is not installed
    if (!nchar(system.file(package = x))) {
      res <- paste0("The package '", x, "' is not installed")
    } else {
      if (is.null(version)) {
        res <- TRUE
      } else {
        # Check if the required version is  installed
        installed_version <- utils::packageDescription(x)$Version
        if (utils::compareVersion(installed_version, version) == -1) {
          res <- paste0("The package '", x, "' version '", installed_version, "' is installed, while version '", version, "' is required.")
        } else {
          res <- TRUE
        }
      }
    }
  }
  if (type == "attached") {
    # TRUE if the package is attached
    if (x %in% (.packages())) {
      res <- TRUE
      # message if the package is not attached
    } else {
      res <- paste0("The package '", x, "' is not attached")
    }
  }
  return(res)

}


#' @export
#' @include makeAssertionFunction.R
#' @template assert
#' @rdname check_package
assert_package <- makeAssertionFunction(check_package)