chore: update benchmark script to include versions

package.json

@@ -73,7 +73,7 @@
     "pkijs": "^3.4.0"
   },
   "devDependencies": {
-    "@cantoo/pdf-lib": "^2.7.1",
+    "@cantoo/pdf-lib": "^2.9.1",
     "@google-cloud/kms": "^5.5.1",
     "@google-cloud/secret-manager": "^6.1.3",
     "@types/bun": "^1.3.14",

scripts/bench-comment.ts

@@ -9,6 +9,8 @@
 
 import { readFileSync } from "node:fs";
 
+import { getLibraryVersions } from "./bench-versions";
+
 interface Bench {
   name: string;
   mean: number;
@@ -116,7 +118,8 @@ const runner = process.env.BENCH_RUNNER ?? "local";
 lines.push(
   `<details><summary>Environment</summary>\n\n` +
     `- Runner: \`${runner}\`\n` +
-    `- Runtime: Bun ${process.versions.bun}\n\n` +
+    `- Runtime: Bun ${process.versions.bun}\n` +
+    `- Libraries: ${getLibraryVersions()}\n\n` +
     `*Results are machine-dependent.*\n` +
     `</details>`,
 );

scripts/bench-report.ts

@@ -14,6 +14,8 @@ import { execSync } from "node:child_process";
 import { existsSync, mkdirSync, readFileSync, writeFileSync } from "node:fs";
 import { cpus, platform, totalmem } from "node:os";
 
+import { getLibraryVersions } from "./bench-versions";
+
 // ─────────────────────────────────────────────────────────────────────────────
 // Types for vitest bench JSON output
 // ─────────────────────────────────────────────────────────────────────────────
@@ -122,6 +124,8 @@ function generateMarkdown(data: BenchmarkOutput): string {
   lines.push(`> Generated on ${dateStr} at ${timeStr} UTC`);
   lines.push(`>`);
   lines.push(`> System: ${getSystemInfo()}`);
+  lines.push(`>`);
+  lines.push(`> Libraries: ${getLibraryVersions()}`);
   lines.push("");
   lines.push("---");
   lines.push("");

scripts/bench-versions.ts

@@ -0,0 +1,64 @@
+/**
+ * Resolves installed versions of the libraries used in benchmark comparisons.
+ *
+ * Versions are read from node_modules at generation time, so reports always
+ * reflect the packages that actually ran, not the semver ranges in
+ * package.json.
+ */
+
+import { readFileSync } from "node:fs";
+import { join } from "node:path";
+
+/** Competitor libraries used in benchmarks/comparison.bench.ts. */
+export const COMPARISON_LIBRARIES = ["pdf-lib", "@cantoo/pdf-lib"] as const;
+
+function readPackageMetadata(path: string): { name?: string; version?: string } {
+  const value: unknown = JSON.parse(readFileSync(path, "utf-8"));
+
+  if (typeof value !== "object" || value === null) {
+    return {};
+  }
+
+  const name = "name" in value && typeof value.name === "string" ? value.name : undefined;
+  const version =
+    "version" in value && typeof value.version === "string" ? value.version : undefined;
+
+  return { name, version };
+}
+
+/**
+ * Read the installed version of a package from node_modules.
+ * Returns "unknown" if the package cannot be resolved.
+ */
+export function getInstalledVersion(name: string, root = process.cwd()): string {
+  try {
+    const pkgPath = join(root, "node_modules", name, "package.json");
+    const pkg = readPackageMetadata(pkgPath);
+
+    return pkg.version ?? "unknown";
+  } catch {
+    return "unknown";
+  }
+}
+
+/**
+ * Format a one-line summary of all benchmarked library versions,
+ * e.g. "@libpdf/core 0.1.0 (this repo), pdf-lib 1.17.1, @cantoo/pdf-lib 2.9.1".
+ */
+export function getLibraryVersions(root = process.cwd()): string {
+  let ownLabel = "@libpdf/core";
+
+  try {
+    const pkg = readPackageMetadata(join(root, "package.json"));
+
+    ownLabel = `${pkg.name ?? "@libpdf/core"} ${pkg.version ?? "unknown"} (this repo)`;
+  } catch {
+    ownLabel = "@libpdf/core unknown (this repo)";
+  }
+
+  const competitors = COMPARISON_LIBRARIES.map(
+    name => `${name} ${getInstalledVersion(name, root)}`,
+  );
+
+  return [ownLabel, ...competitors].join(", ");
+}