benchmarkjs 测试函数性能

安装

npm i --save benchmark

官方例子

var Benchmark = require("benchmark");

var suite = new Benchmark.Suite;

// add tests
suite
  .add("RegExp#test", function () {
    /o/.test("Hello World!");
  })
  .add("String#indexOf", function () {
    "Hello World!".indexOf("o") > -1;
  })
  // add listeners
  .on("cycle", function (event) {
    console.log("event", event)
    console.log(String(event.target));
  })
  .on("complete", function () {
    console.log("this", this)
    console.log("Fastest is " + this.filter("fastest").map("name"));
  })
  // run async
  .run({"async": true});

// logs:
// => RegExp#test x 4,161,532 +-0.99% (59 cycles)
// => String#indexOf x 6,139,623 +-1.00% (131 cycles)
// => Fastest is String#indexOf

自己测个demo

果然还是数组快

const Benchmark = require("benchmark");

const suite = new Benchmark.Suite;

function getStr() {
  return Math.random().toString(36).slice(2)
}

let s1 = getStr()
let s2 = "o" + getStr()
let s3 = "on" + getStr()

let list = [
  s1, s2, s3
]

// add tests
suite
  .add("String#startsWith", function () {
    list.map(
      s => s.startsWith("on")
    )
  })
  .add("Array#index", function () {
    list.map(
      s => s[0] === "o" && s[1] === "n"
    )
  })
  // add listeners
  .on("cycle", function (event) {
    // console.log("event", event)
    console.log(String(event.target));
  })
  .on("complete", function () {
    // console.log("this", this)
    console.log("Fastest is ", this.filter("fastest").map("name"));
    console.log("name is ", this.map("name"));
    console.log("mean is ", this.map("stats").map(x => x.mean));
    // console.log("times is ", this.map("times"));
  })
  // run async
  .run({"async": true});

// String#startsWith x 10,141,354 ops/sec ±1.20% (90 runs sampled)
// Array#index x 32,883,950 ops/sec ±0.98% (91 runs sampled)
// Fastest is  [ "Array#index" ]
// name is  [ "String#startsWith", "Array#index" ]
// mean is  [ 9.860616140762061e-8, 3.04099715762954e-8 ]