benchmate

Benchmate is a small but mighty benchmarking library for JavaScript.

Comes with sensible defaults and tries to figure out the best parameters on its own.
Supports duration and iteration count targeting.
Works with both process.hrtime and performance.now.
Has hooks for setup and teardown (before and after the entire test, not each execution).
Has async support, but you really shouldn't benchmark async functions.
Returns the metrics and prints the output nicely (optional).

Demo

Installation

Benchmate is published on the NPM registry: https://npmjs.com/package/benchmate

npm install -D benchmate
pnpm install -D benchmate
yarn add -D benchmate

Usage

Notes:

Don't disable batching if you want accurate measurements. Metrics like min, max, and percentiles will me meaningless, as you get a single measurement.
Don't expect accurate timings for fast async functions, but you can compare their performance.

import { Bench } from "benchmate";

// The default options are sensible,
const bench = new Bench({
  iterations: "auto", // number of iterations, must be "auto" when using time 
  time: 1000, // target running time for tasks                              
  batching: { // batching improves accuracy by a <lot>
    enabled: true,
    size: "auto" // number of iterations per batch or "auto"
  },
  warmup: {
    enabled: true,
    size: "auto", // number of warmup iterations or "auto" for (iterations / 10)
  },
  method: "auto", // "auto" | "hrtime" | "performance.now" - measurement method, defaults to best available
  testSleepDuration: 0, // how long to sleep between tasks (ms)
  quiet: false, // don't print anything, defaults to `true` in browsers, `false` in Node
  setup: () => Promise<void> | void, // function to run before each test
  teardown: () => Promise<void> | void, // function to run after each test
});

bench.add("RegExp#test", () => {
  if (!/o/.test("Hello World!")) console.log("nop");
});

bench.add("String#indexOf", () => {
  if ("Hello World!".indexOf("o") === -1) console.log("nop");
});

await bench.run();
// ^ returns an array of benchmark results:
// type BenchmarkResult = {
//   name: string;
//   stats: {
//     samples: number;
//     batches: number;
//     time: { // all timings are in milliseconds
//       total: number;
//       min: number;
//       max: number;
//       average: number;
//       percentile50: number;
//       percentile90: number;
//       percentile95: number;
//     };
//     opsPerSecond: {
//       average: number;
//       max: number;
//       min: number;
//       margin: number; // percentage
//     };