react-experiment-hoc/src/api.js

Simple hoc to provide a/b-test features.

import weighted from './weighted';

export const getVariant = (variants, experiment, fallback, persistent, setCookie, getCookie) => {
  const key = `experiment_${experiment}${persistent}`;
  const cookieIndex = getCookie(key);
  let index = cookieIndex;
  
  if (!index || !variants[index] || persistent < 0)
    index = weighted(variants.map(v => v.weight));

  if (!cookieIndex && !fallback && persistent >= 0)
    setCookie(key, index, {
      path: '/',
      expires: !persistent ? null : new Date(Date.now()+(60 * 60 * 24 * 365 * 10 * 1000)),
    });

  return variants[index].name;
}