Checks if there are missing value tags in any man pages

check_missing_value.R

# Function to run to check if you have any missing `\value{}` tags 
check_missing_value <- function(pkg = ".") {
  pkg_root <- rprojroot::find_package_root_file(path = pkg)
  # find exported functions
  ns <- readLines(file.path(pkg_root, "NAMESPACE"))
  exports <- ns[which(grepl("export", ns))]
  # https://stackoverflow.com/questions/8613237/extract-info-inside-all-parenthesis-in-r
  exported_fxs <- stringr::str_extract(exports, "(?<=\\().+?(?=\\))")
  
  # parse all man pages
  all_mans <- fs::dir_ls(file.path(pkg_root, "man"), type = "file")
  man_checks <- purrr::map(all_mans, has_value_tag, exported_fxs)
  
  man_checks |> 
    tibble::enframe() |> 
    tidyr::unnest_wider(value) |> 
    tidyr::unnest_longer(functions) |> 
    dplyr::arrange(value)
}


# Helper function to use per man page
has_value_tag <- function(help, exported_fxs) {
  man <- tools::parse_Rd(help) 
  get_tags <- purrr::attr_getter("Rd_tag")
  man_tags <- purrr::map_chr(man, get_tags)
  fx_names <- unlist(man[man_tags == "\\alias"])
  
  fxs <- fx_names[fx_names %in% exported_fxs]
  if (length(fxs) == 0) {
    return(list(functions = NA, value = NA))
  }
  
  has_value <- any(man_tags == "\\value")
  
  if (!has_value) cli::cli_alert_info("{fx_names} require `@return` tag")
  list(functions = fx_names, value = has_value)
}



# check your package
check_missing_value()