redux-ab-test/dist/utils/random-variation.js

A/B testing React components with Redux and debug tools. Isomorphic with a simple, universal interface. Well documented and lightweight. Tested in popular browsers and Node.js. Includes helpers for React, Redux, and Segment.io

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.toRanges = exports.toRange = exports.toTotal = exports.toWeight = undefined;

var _stringify = require('babel-runtime/core-js/json/stringify');

var _stringify2 = _interopRequireDefault(_stringify);

exports['default'] = randomVariation;

var _immutable = require('immutable');

var _immutable2 = _interopRequireDefault(_immutable);

var _logger = require('./logger');

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { 'default': obj }; }

// Helper to convert variation => weight:number
var toWeight = exports.toWeight = function () {
  function toWeight(variation) {
    return variation.get('weight') || 0;
  }

  return toWeight;
}();

// Calculate the total weight
var toTotal = exports.toTotal = function () {
  function toTotal(variations) {
    return variations.reduce(function (total, variation) {
      return total + toWeight(variation);
    }, 0);
  }

  return toTotal;
}();

// Generate the next range in the series
var toRange = exports.toRange = function () {
  function toRange(list, counter) {
    var startAt = list.count() <= 0 ? 0 : list.last().last() + 1;
    var range = _immutable2['default'].Range(startAt, startAt + counter);
    return list.push(range);
  }

  return toRange;
}();

// Geneate a contigious range of scores
var toRanges = exports.toRanges = function () {
  function toRanges(variations) {
    return variations.map(toWeight).reduce(toRange, _immutable2['default'].List([]));
  }

  return toRanges;
}();

function randomVariation(experiment) {
  var random = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : Math.random;

  var variations = experiment.get('variations').sortBy(toWeight).reverse();
  var weightTotal = toTotal(variations);
  var weightRanges = toRanges(variations);
  var weightRandom = Math.round(weightTotal * random());
  (0, _logger.logger)(__filename + ' randomVariation experiment.name=\'' + experiment.get('name') + '\', variations=\'' + (0, _stringify2['default'])(variations) + '\'');
  (0, _logger.logger)(__filename + ' randomVariation experiment.name=\'' + experiment.get('name') + '\', weightTotal=\'' + (0, _stringify2['default'])(weightTotal) + '\'');
  (0, _logger.logger)(__filename + ' randomVariation experiment.name=\'' + experiment.get('name') + '\', weightRanges=\'' + (0, _stringify2['default'])(weightRanges) + '\'');
  (0, _logger.logger)(__filename + ' randomVariation experiment.name=\'' + experiment.get('name') + '\', weightRandom=\'' + (0, _stringify2['default'])(weightRandom) + '\'');

  // Find the range that contains our score
  var index = weightRanges.findIndex(function (range) {
    return range.includes(weightRandom);
  });
  (0, _logger.logger)(__filename + ' randomVariation experiment.name=\'' + experiment.get('name') + '\', index=\'' + (0, _stringify2['default'])(index) + '\'');

  // Return the matching variation.  Returns variations.last() if random() was out of range [0, 1)
  var variation = variations.get(index, variations.last());
  (0, _logger.logger)(__filename + ' randomVariation experiment.name=\'' + experiment.get('name') + '\', variation.name=\'' + (variation && variation.get('name')) + '\'');
  return variation;
}