Split testing

The purpose of this module is to aid in split testing node.js based
applications, whether it's in the browser, or backends.

Scope

This module provides a generic way to setup and measure experiments
with weighted outcomes.

Conclusions of what outcome performed the best cannot be determined
only by using this module.

Example usage

``js
import { Experiment } from 'eleanor-split-test';

// setup the experiment
const experiment = new Experiment({
// Name of this test, to be able to distinguish between tests when running
// multiple at the same time.
name: 'green-vs-red-btn',
// Configure the different outcomes that you want to test, along with a
// weight that tells how likely the outcome is.
outcomes: [
['green', 0.5],
['red', 0.5],
],
// Supply a function that will be triggered when evaluating an experiment.
report: (experimentName, outcomeName, userId) => {
console.log('Send to your favorite analytics service');
},
// (Optional) Persisting functions, when you want the first outcome be become
// sticky for this particular user.
persist: {
read,
write,
},
// (Optional) Used in multi-user contexts, such as backend applications to
// distinguish between users when persisting the outcome.
userId: 3,
});

// evaluate the actual experiment
experiment.evaluate().then(outcomeName => {
console.log('Lets go with the', outcomeName, 'button');
});

// Example of persisting functions
const fakeDb = {};

function read(key) {
return Promise.resolve(fakeDb[key]);
}

function write(key, outcome) {
fakeDb[key] = outcome;
return Promise.resolve();
}
``