feat: create csv reporter

README.md

@@ -277,6 +277,35 @@ const suite = new Suite({
 });
 ```
 
+### CSV Reporter
+
+The `csvReport` plugin generates benchmark results in CSV format.
+It includes columns for key performance metrics like `ops/sec`, `samples`, `min` and `max` times,
+as well as any reporter data provided by your plugins.
+
+Example output:
+
+```csv
+name,ops/sec,samples,plugins,min,max
+Using delete property,"7,732,517",10,v8-never-optimize=true,127.91ns,129.95ns
+Using delete property (proto: null),"24,636,631",10,v8-never-optimize=true,39.57ns,40.91ns
+Using delete property (cached proto: null),"7,497,893",11,v8-never-optimize=true,132.25ns,134.89ns
+Using undefined assignment,"132,093,600",11,v8-never-optimize=true,7.53ns,7.64ns
+Using undefined assignment (proto: null),"28,231,374",9,v8-never-optimize=true,35.27ns,35.42ns
+Using undefined property (cached proto: null),"60,843,193",10,v8-never-optimize=true,16.24ns,16.65ns
+[Managed] Using undefined property (cached proto: null),"35,394,060",10,v8-never-optimize=true,27.90ns,28.54ns
+```
+
+**Usage:**
+
+```cjs
+const { Suite, csvReport } = require('bench-node');
+
+const suite = new Suite({
+  reporter: csvReport,
+});
+```
+
 ### Custom Reporter
 
 Customize data reporting by providing a `reporter` function when creating the `Suite`:

lib/index.js

@@ -2,7 +2,13 @@ const { Worker } = require("node:worker_threads");
 const { types } = require("node:util");
 const path = require("node:path");
 
-const { textReport, chartReport, htmlReport, jsonReport } = require("./report");
+const {
+	textReport,
+	chartReport,
+	htmlReport,
+	jsonReport,
+	csvReport,
+} = require("./report");
 const {
 	getInitialIterations,
 	runBenchmark,
@@ -229,4 +235,5 @@ module.exports = {
 	textReport,
 	htmlReport,
 	jsonReport,
+	csvReport,
 };

lib/report.js

@@ -2,10 +2,12 @@ const { textReport } = require("./reporter/text");
 const { chartReport } = require("./reporter/chart");
 const { htmlReport } = require("./reporter/html");
 const { jsonReport } = require("./reporter/json");
+const { csvReport } = require("./reporter/csv");
 
 module.exports = {
 	chartReport,
 	textReport,
 	htmlReport,
 	jsonReport,
+	csvReport,
 };

lib/reporter/csv.js

@@ -0,0 +1,36 @@
+const { timer } = require("../clock");
+
+const formatter = Intl.NumberFormat(undefined, {
+	notation: "standard",
+	maximumFractionDigits: 2,
+});
+
+function csvReport(results) {
+	process.stdout.write("name,ops/sec,samples,plugins,min,max\n");
+
+	for (const result of results) {
+		const opsSecReported =
+			result.opsSec < 100 ? result.opsSec.toFixed(2) : result.opsSec.toFixed(0);
+
+		process.stdout.write(`${result.name},`);
+
+		process.stdout.write(`"${formatter.format(opsSecReported)}",`);
+
+		process.stdout.write(`${result.histogram.samples},`);
+
+		process.stdout.write(
+			`"${result.plugins
+				.filter((p) => p.report)
+				.map((p) => p.report)
+				.join(",")}",`,
+		);
+
+		process.stdout.write(`${timer.format(result.histogram.min)},`);
+
+		process.stdout.write(`${timer.format(result.histogram.max)}\n`);
+	}
+}
+
+module.exports = {
+	csvReport,
+};

test/reporter.js

@@ -2,7 +2,13 @@ const { describe, it, before } = require("node:test");
 const assert = require("node:assert");
 const fs = require("node:fs");
 
-const { Suite, chartReport, htmlReport, jsonReport } = require("../lib");
+const {
+	Suite,
+	chartReport,
+	htmlReport,
+	jsonReport,
+	csvReport,
+} = require("../lib");
 
 describe("chartReport outputs benchmark results as a bar chart", async (t) => {
 	let output = "";
@@ -190,3 +196,70 @@ describe("jsonReport should produce valid JSON output", async () => {
 		}
 	});
 });
+
+describe("csvReport", () => {
+	it("should generate valid CSV output", async (t) => {
+		const fn = t.mock.method(process.stdout, "write");
+
+		// noop
+		fn.mock.mockImplementation(() => {});
+
+		csvReport([
+			{
+				opsSec: 749625.5652171721,
+				iterations: 374813,
+				histogram: {
+					samples: 10,
+					min: 1322.2615873857162,
+					max: 1345.4275821344213,
+				},
+				name: "single with matcher",
+				plugins: [
+					{
+						name: "V8NeverOptimizePlugin",
+						result: "enabled",
+						report: "v8-never-optimize=true",
+					},
+				],
+			},
+			{
+				opsSec: 634284.7401772924,
+				iterations: 317148,
+				histogram: {
+					samples: 11,
+					min: 1552.562466504839,
+					max: 1612.7852084972462,
+				},
+				name: "Multiple replaces",
+				plugins: [
+					{
+						name: "V8NeverOptimizePlugin",
+						result: "enabled",
+						report: "v8-never-optimize=true",
+					},
+				],
+			},
+		]);
+
+		const callArgs = process.stdout.write.mock.calls.map(
+			(call) => call.arguments[0],
+		);
+
+		assert.strictEqual(process.stdout.write.mock.callCount(), 13);
+		assert.deepStrictEqual(callArgs, [
+			"name,ops/sec,samples,plugins,min,max\n",
+			"single with matcher,",
+			'"749,626",',
+			"10,",
+			'"v8-never-optimize=true",',
+			"1.32us,",
+			"1.35us\n",
+			"Multiple replaces,",
+			'"634,285",',
+			"11,",
+			'"v8-never-optimize=true",',
+			"1.55us,",
+			"1.61us\n",
+		]);
+	});
+});