fix-perf.js

"use strict";

/* eslint no-console: off */

const fs = require("fs");
const cp = require("child_process");

const TEST_FILE_DATA = JSON.stringify(
    Array.from({ length: 1024 }, () => ({
        aaa: Math.random(),
        bbb: Math.random(),
        ccc: Math.random()
    })),
    null,
    4
);
const N = 7;

console.log("started.");

const times = [];

for (let i = 0; i < N; ++i) {
    fs.writeFileSync(".test.js", TEST_FILE_DATA);

    const start = Date.now();

    cp.spawnSync(process.execPath, ["bin/eslint.js", "--fix", "--no-ignore", ".test.js"], { stdio: "ignore" });

    const time = Date.now() - start;

    times.push(time);
    console.log(`[${i + 1}]`, time, "ms");
}

console.log("----------------");
console.log("[#]", times.sort()[N / 2 | 0], "ms");

fs.unlinkSync(".test.js");

A result:

~\Documents\GitHub\eslint [refactor-fix]> node test.js
started.
[1] 1898 ms
[2] 1876 ms
[3] 1862 ms
[4] 1853 ms
[5] 1879 ms
[6] 1871 ms
[7] 1869 ms
----------------
[#] 1871 ms
~\Documents\GitHub\eslint [refactor-fix]> git checkout master
Your branch is up-to-date with 'origin/master'.
Switched to branch 'master'
~\Documents\GitHub\eslint [master ≡]> node test.js
started.
[1] 2406 ms
[2] 2299 ms
[3] 2408 ms
[4] 2367 ms
[5] 2347 ms
[6] 2366 ms
[7] 2363 ms
----------------
[#] 2366 ms