Quick benchmarking utility function

test.js

/**
// HOW TO USE IT 
const test = require('./wherever/it/is/test')
function myFunc1 (a,b) { ... }
function myFunc2 (a,b) { ... }
const benchs = [{
    in: [[1,2,3.4], 'test'],
    out: true
}, ...]
test(
    benchs,
    [myFunc1, myFunc2],
    {iterations:1e3, stepDetail: false}// default
)
*/
const formatX = (map, base) => (s, prec = 2) => {
        if (s == 0) return `0 ${base}`;
        let n = 0, nInt = 0;
        for (let i in map) {
            if (s >= map[i]) {
                n = parseFloat((s / map[i]).toFixed(prec), 10);
                nInt = parseInt(n, 10);
                n =  n == nInt ? nInt : n;
                return `${n} ${i}`;
            }
        }
    },
    formatSize = formatX({GB: 2 << 29, MB: 2 << 19, KB: 2 << 9, B: 1}, 'B'),
    formatTime = formatX({m: 60e3, s: 1e3, ms: 1, µs: 1e-3, ns: 1e-6}, 'ms');

module.exports =  (bs, imp, options = {}) => {
    const iterations = options.iterations || 1e3,
        stepDetail = options.stepDetail || false,
        impls = (imp.constructor.name === 'Array') ? imp : [imp],
        globs = [];
    impls.forEach(impl => {
        const name = impl.name;
        console.log(`› Testing \`${name}\``);
        const out = {ok: 0, ko : 0},
            times = [],
            sym = ['\u2717','\u2713' ],
            upStart = + new Date();
        bs.forEach((b, i) => {
            const start = +new Date();
            let j = 0, r;
            while (j++ < iterations) r = impl(...b.in);
            const end = +new Date();
            times[i] = end - start;
            
            const spent = formatTime(times[i] / iterations);
            if (JSON.stringify(r) === JSON.stringify(b.out)){
                stepDetail && console.log(`${sym[1]} test #${i+1} passed ${spent}`);
                out.ok++;
            } else {
                if (stepDetail) {
                    console.log(`${sym[0]} test #${i+1} failed ${spent}`);
                    console.log('| expected:', b.out);
                    console.log('| received:', r);
                    console.log('\'+-------');
                }
                out.ko++;
            }
        })
        var upEnd = + new Date(),
            globTime = upEnd - upStart;
        console.log(`Passed ${out.ok} | Failed ${out.ko}`);
        console.log(`Total time ${formatTime(globTime, 1)}`);
        if (!out.ko) {
            globs.push({name, time : globTime})
        }
        console.log(`Consuming ~${formatSize(process.memoryUsage().heapUsed)}`)
        console.log('')
    })
    if (globs.length > 1) {
        console.log('∆ PODIUM')
        globs.sort((a,b) => a.time - b.time).forEach((impl, i) => {
            console.log(`${i+1}${['st','nd','rd',][i] || 'th'} place to ${impl.name} : ${formatTime(impl.time)}`)
        })
    }
}