Introduce box plot drawing script

extras/boxplot_xml.R

@@ -0,0 +1,34 @@
+library(XML)
+library(ggplot2)
+
+args <- commandArgs(trailingOnly = TRUE)
+data <- xmlParse(args[1])
+
+for (test_case in data["//TestCase"]) {
+  test_case_name <- xpathSApply(test_case, "./@name", paste)
+  results <- xpathSApply(test_case, ".//BenchmarkResults")
+  samples <- xpathSApply(test_case, ".//sample", xmlValue)
+  counts <- xpathSApply(test_case, ".//BenchmarkResults", function(r) {
+    xmlGetAttr(r, "samples", default = 0, converter = as.integer)
+  })
+  names <- xpathSApply(test_case, ".//BenchmarkResults/@name", paste)
+
+  if (length(names) == 0 || sum(counts) == 0) next
+  names <- rep(names, counts)
+
+  df <- data.frame(
+    methods = names,
+    samples = as.numeric(samples)
+  )
+
+  p <- ggplot(df, aes(x = methods, y = samples, fill = methods)) +
+    geom_boxplot(size = 0.5, staplewidth = 0.5) +
+    theme(axis.text.x = element_text(angle = -45, vjust = 1, hjust = 0)) +
+    labs(x = "Benchmark", y = "Time [ns]", title = test_case_name, fill = "Benchmark") +
+    scale_y_continuous(limits = c(0, NA))
+  print(p)
+  test_case_name |>
+    gsub(pattern = "\\s", replacement = "_") |>
+    paste(".png", sep = "") |>
+    ggsave()
+}

src/catch2/reporters/catch_reporter_xml.cpp

@@ -250,6 +250,12 @@ namespace Catch {
             .writeAttribute("lowSevere"_sr, benchmarkStats.outliers.low_severe)
             .writeAttribute("highMild"_sr, benchmarkStats.outliers.high_mild)
             .writeAttribute("highSevere"_sr, benchmarkStats.outliers.high_severe);
+        auto samples = m_xml.scopedElement("samples");
+        for (auto const& sample : benchmarkStats.samples) {
+            m_xml.startElement("sample", XmlFormatting::Indent)
+                .writeText(std::to_string(sample.count()), XmlFormatting::None)
+                .endElement(XmlFormatting::Newline);
+        }
         m_xml.endElement();
     }