Exporting metrics

DESCRIPTION

@@ -45,6 +45,6 @@ Suggests:
     testthat,
     webmockr,
     jsonlite
-RoxygenNote: 7.2.3
+RoxygenNote: 7.3.2
 VignetteBuilder: knitr
 Config/testthat/edition: 3

NAMESPACE

@@ -76,6 +76,8 @@ S3method(pillar_shaft,pkg_metric_error)
 S3method(pkg_assess,list_of_pkg_ref)
 S3method(pkg_assess,pkg_ref)
 S3method(pkg_assess,tbl_df)
+S3method(pkg_metric_export,list)
+S3method(pkg_metric_export,tbl_df)
 S3method(pkg_score,list_of_pkg_metric)
 S3method(pkg_score,tbl_df)
 S3method(print,pkg_ref)
@@ -116,6 +118,8 @@ export(get_assessments)
 export(metric_score)
 export(pkg_assess)
 export(pkg_metric)
+export(pkg_metric_export)
+export(pkg_metric_import)
 export(pkg_ref)
 export(pkg_score)
 export(score_error_NA)

R/pkg_metric_export.R

@@ -0,0 +1,89 @@
+# Converts snake_case to PascalCase
+to_pascal_case <- function(x) {
+  words <- strsplit(x, "_")[[1]]
+  paste0(toupper(substring(words, 1, 1)), substring(words, 2), collapse = "")
+}
+
+#' Flatten scored metrics to DCF-style key-value pairs
+#'
+#' `pkg_metric_export()` converts scored package metrics into a flat list of
+#' character strings in DCF (Debian Control File) style. Each metric is
+#' written as a line in the form `Metric<Name>: <value>`, where `<Name>` is the
+#' PascalCase transformation of the metric name.
+#'
+#' This is useful for exporting results from `pkg_score()` into formats that
+#' require simple key-value structures.
+#'
+#' @param x A `tbl_df` or `list` returned by `pkg_score()`, containing scored
+#'   `pkg_metric` values. The input may come from `pkg_score.tbl_df()` (for
+#'   many packages) or `pkg_score.list_of_pkg_metric()` (for a single package).
+#' @param ... additional arguments unused
+#'
+#' @return A character vector, where each element is a DCF-style line
+#'   representing one scored metric (e.g., `"MetricHasNews: 1"`).
+#' @seealso pkg_metric_import
+#' @examples
+#' \dontrun{
+#' # For a single package
+#' metrics <- pkg_score(pkg_assess(pkg_ref("riskmetric")))[[1]]
+#' pkg_metric_export(metrics)
+#'
+#' # For a data frame of packages
+#' library(dplyr)
+#' scores <- pkg_score(pkg_assess(as_tibble(pkg_ref("riskmetric"))))
+#' pkg_metric_export(scores[1, ])  # flatten first package's results
+#' }
+#'
+#' @export
+pkg_metric_export <- function(x, ...) {
+  UseMethod("pkg_metric_export")
+}
+
+#' @export
+pkg_metric_export.list <- function(x, file = "PACKAGES", ...) {
+  record <- list()
+  for (name in names(x)) {
+    pascal_name <- paste0("Metric", to_pascal_case(name))
+    value <- as.character(x[[name]][1])
+
+    # Replace NA values with "NA" string
+    record[[pascal_name]] <- ifelse(is.na(value), "NA", value)
+  }
+
+  # Convert to one-row data frame
+  df <- as.data.frame(record, stringsAsFactors = FALSE)
+  write.dcf(df, file = file)
+  df
+}
+
+#' @export
+pkg_metric_export.tbl_df <- function(x, file = "PACKAGES", ...) {
+  x <- x[, setdiff(names(x), "pkg_ref")]
+
+  records <- lapply(seq_len(nrow(x)), function(i) {
+    row <- x[i, , drop = FALSE]
+    record <- list()
+
+    for (name in names(row)) {
+      value <- as.character(row[[name]])
+
+      # Replace NA values with "NA" string
+      value <- ifelse(is.na(row[[name]]), "NA", value)
+
+      # Leave Package and Version untouched
+      if (name %in% c("package", "version")) {
+        pascal_name <- paste0(toupper(substring(name, 1, 1)), substring(name, 2))
+        record[[pascal_name]] <- value
+      } else {
+        pascal_name <- paste0("Metric", to_pascal_case(name))
+        record[[pascal_name]] <- value
+      }
+    }
+
+    record
+  })
+
+  df <- do.call(rbind.data.frame, lapply(records, as.data.frame, stringsAsFactors = FALSE))
+  write.dcf(df, file = file)
+  df
+}

R/pkg_metric_import.R

@@ -0,0 +1,15 @@
+#' Import metrics
+#'
+#' @param file (`character`) Path to the file to import.
+#'
+#' @returns The object in the same format and class as generated by riskmetric.
+#' @export
+#' @seealso pkg_metric_export()
+pkg_metric_import <- function(file) {
+  if (!file.exists(file)) {
+    stop("Please provide a path to a file.")
+  }
+  dcf <- read.dcf(file)
+  dcf <- as.data.frame(dcf)
+  dcf
+}