feat: add fastest/slowest value for feature parity with benchmark.js

* chore: Rename analysis file from baseline.js -> analyze.js

Implements #101

* chore: Formatting fixups.

Author: jdmarshall

lib/reporter/chart.js

@@ -1,6 +1,6 @@
 const { platform, arch, availableParallelism, totalmem } = require("node:os");
 const { styleText } = require("../utils/styleText");
-const { analyze } = require("../utils/baseline.js");
+const { analyze } = require("../utils/analyze.js");
 
 /**
  * Draws a bar chart representation of a benchmark result

lib/reporter/pretty.js

@@ -1,7 +1,7 @@
 const { styleText } = require("../utils/styleText");
 const { timer } = require("../clock");
 const os = require("node:os");
-const { analyze } = require("../utils/baseline");
+const { analyze } = require("../utils/analyze.js");
 
 const formatter = Intl.NumberFormat(undefined, {
 	notation: "standard",

lib/reporter/text.js

@@ -1,6 +1,6 @@
 const { styleText } = require("../utils/styleText");
 const { timer } = require("../clock");
-const { analyze } = require("../utils/baseline.js");
+const { analyze } = require("../utils/analyze.js");
 
 const formatter = Intl.NumberFormat(undefined, {
 	notation: "standard",

lib/utils/baseline.js lib/utils/analyze.jslib/utils/baseline.js renamed to lib/utils/analyze.js

@@ -7,20 +7,31 @@ function analyze(results, sorted = true) {
 		return output;
 	}
 
-	if (sorted) {
-		output.sort((a, b) => {
-			if (a.baseline) return -1;
-			if (b.baseline) return 1;
-			return (a.opsSec || 0) - (b.opsSec || 0);
-		});
-	}
-
 	const baselineHz = baselineResult.opsSec;
+	let min = Number.MAX_SAFE_INTEGER;
+	let max = Number.MIN_SAFE_INTEGER;
+
+	let fastest;
+	let slowest;
 
 	for (const result of output) {
-		if (!result.baseline && result.opsSec !== undefined) {
-			const benchmarkHz = result.opsSec;
+		const benchmarkHz = result.opsSec;
+
+		if (benchmarkHz === undefined) {
+			continue;
+		}
 
+		if (benchmarkHz > max) {
+			max = benchmarkHz;
+			fastest = result;
+		}
+
+		if (benchmarkHz < min) {
+			min = benchmarkHz;
+			slowest = result;
+		}
+
+		if (!result.baseline) {
 			if (benchmarkHz > baselineHz) {
 				result.comparison = (benchmarkHz / baselineHz).toFixed(2);
 			} else {
@@ -29,6 +40,22 @@ function analyze(results, sorted = true) {
 		}
 	}
 
+	if (fastest !== undefined) {
+		fastest.fastest = true;
+	}
+
+	if (slowest !== undefined) {
+		slowest.slowest = true;
+	}
+
+	if (sorted) {
+		output.sort((a, b) => {
+			if (a.baseline) return -1;
+			if (b.baseline) return 1;
+			return (a.opsSec || 0) - (b.opsSec || 0);
+		});
+	}
+
 	return output;
 }
 

test/reporter.js

@@ -12,6 +12,8 @@ const {
 	textReport,
 } = require("../lib");
 
+const { analyze } = require("../lib/utils/analyze.js");
+
 describe("chartReport outputs benchmark results as a bar chart", async (t) => {
 	let output = "";
 
@@ -285,6 +287,42 @@ describe("prettyReport outputs a beautiful report", async (t) => {
 	});
 });
 
+describe("analyse", async (t) => {
+	let analysis;
+
+	before(async () => {
+		// Create a new Suite with the pretty reporter
+		const suite = new Suite({});
+
+		// Add benchmarks with one being the baseline
+		suite
+			.add("baseline-test", { baseline: true }, () => {
+				// Medium-speed operation
+				for (let i = 0; i < 10000; i++) {}
+			})
+			.add("other-test", () => {
+				// Faster operation
+				for (let i = 0; i < 1000; i++) {}
+			})
+			.add("faster-test", () => {
+				// Slower operation
+				for (let i = 0; i < 100; i++) {}
+			});
+
+		// Run the suite
+		const results = await suite.run();
+		analysis = analyze(results, false);
+	});
+
+	it("annotates the fastest result", () => {
+		assert.equal(analysis[2].fastest, true, "fastest result");
+	});
+
+	it("annotates the slowest result", () => {
+		assert.equal(analysis[0].slowest, true, "slowest result");
+	});
+});
+
 describe("baseline comparisons", async (t) => {
 	let results;
 
@@ -311,6 +349,22 @@ describe("baseline comparisons", async (t) => {
 		results = await suite.run();
 	});
 
+	describe("analyze", () => {
+		let analysis;
+
+		before(() => {
+			analysis = analyze(results);
+		});
+
+		it("annotates the fastest result", () => {
+			assert.equal(results[1].fastest, true, "fastest result");
+		});
+
+		it("annotates the slowest result", () => {
+			assert.equal(results[2].slowest, true, "slowest result");
+		});
+	});
+
 	describe("for prettyReport", async (t) => {
 		let output = "";