A/B testing 2 different approaches

ab-testing.js

function createSamples(name, createVariation) {
    const sampleCount = 10000;
    const variations = [];

    for (let i = 0; i < sampleCount; i++) {
        variations.push(createVariation());
    }

    const countData = variations.reduce((accum, curr) => {
        if (accum[curr]) {
            accum[curr]++;
        } else {
            accum[curr] = 1;
        }

        return accum;
    }, {});

    const countPercent = Object.entries(countData).reduce((accum, curr) => {
        const percentage = (curr[1] / sampleCount) * 100;
        accum[curr[0]] = `${Math.round(percentage * 100) / 100}%`;
        return accum;
    }, {});

    console.group(name);
    console.log(countPercent);
    console.groupEnd();
}

// ================ First approach ================

function getRandomVariation1(experimentNeeded) {
    const indexes = [];

    for (let variationName in experimentNeeded) {
        for (let i = 0; i < experimentNeeded[variationName]; i++) {
            indexes.push(variationName);
        }
    }

    const randomKey = indexes[Math.floor(Math.random() * indexes.length)];

    return randomKey;
}

const experimentNeeded = {
    V1: 25,
    V2: 25,
    V3: 25,
    V4: 25
};

// ================ Second approach ================

const randomVariations = ['V1', 'V2', 'V3', 'V4'];

function getRandomVariation2(variations) {
    function getRandomIntInclusive(min, max) {
        min = Math.ceil(min);
        max = Math.floor(max);
        return Math.floor(Math.random() * (max - min + 1) + min);
    }

    return variations[getRandomIntInclusive(0, variations.length - 1)];
}

// ================ Running experiments ================

for (let i = 1; i < 6; i++) {
    console.group(`
Experiment ${i}`);
    createSamples('First Approach', () => getRandomVariation1(experimentNeeded));
    createSamples('Second Approach', () => getRandomVariation2(randomVariations));
    console.groupEnd();
    console.log('=============================================');
}