redux-ab-test/src/utils/select-variation.jest.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

import Immutable from 'immutable';
import createCacheStore from './create-cache-store';
import selectVariation from './select-variation';

const variation_original = {
  name:   'Original',
  weight: 5000,
};
const variation_a = {
  name:   'Variation #A',
  weight: 5000,
};
const variation_b = {
  name:   'Variation #B',
  weight: 0,
};
const experiment = {
  name:       'Test-Name',
  variations: [
    variation_original,
    variation_a,
    variation_b,
  ],
};


describe('utils/select-variation.js', () => {

  it('exists', () => {
    expect(selectVariation).not.toBeUndefined;
    expect(typeof selectVariation).toEqual('function');
  });

  it('chooses the active variation from redux store w/o cacheStore', () => {
    const output = selectVariation({
      active:               Immutable.fromJS({'Test-Name': 'Variation #B'}),
      experiment:           Immutable.fromJS(experiment),
      defaultVariationName: null,
    });
    expect(output).not.toBeUndefined;
    expect(output.toJSON()).toEqual(variation_b);
  });

  it('chooses the active variation from redux store w/cacheStore', () => {
    const cacheStore = createCacheStore();
    const output = selectVariation({
      active:               Immutable.fromJS({'Test-Name': 'Variation #B'}),
      experiment:           Immutable.fromJS(experiment),
      defaultVariationName: null,
      cacheStore:           cacheStore,
    });
    expect(output).not.toBeUndefined;
    expect(output.toJSON()).toEqual(variation_b);
    // Cache does not have the selected variation, since it is stored in redux state!
    expect(Object.keys(cacheStore.cache()).length).toEqual(0);
  });

  it('chooses the defaultVariationName variation', () => {
    const cacheStore = createCacheStore();
    const output = selectVariation({
      active:               Immutable.fromJS({}),
      experiment:           Immutable.fromJS(experiment),
      defaultVariationName: 'Variation #B',
      cacheStore:           cacheStore,
    });
    expect(output).not.toBeUndefined;
    expect(output.toJSON()).toEqual(variation_b);
    // Cache has the selected variation
    expect(cacheStore.cache().length).not.toEqual(0);
    expect(cacheStore.cache()[experiment.name]).toEqual(output.toJSON().name);
  });

  it('chooses the active variation from :cacheStore', () => {
    const cacheStore = createCacheStore();
    cacheStore.setItem(experiment.name, variation_b.name);
    const output = selectVariation({
      active:               Immutable.fromJS({}),
      experiment:           Immutable.fromJS(experiment),
      defaultVariationName: null,
      cacheStore:           cacheStore,
    });
    expect(output).not.toBeUndefined;
    expect(output.toJSON()).toEqual(variation_b);
    // Cache has the selected variation
    expect(cacheStore.cache().length).not.toEqual(0);
    expect(cacheStore.cache()[experiment.name]).toEqual(output.toJSON().name);
  });

  it('randomly assigns a variation, ignoring weight=0 records', () => {
    const cacheStore = createCacheStore();
    const output = selectVariation({
      active:               Immutable.fromJS({}),
      experiment:           Immutable.fromJS(experiment),
      defaultVariationName: null,
      cacheStore,
    });
    expect(output).not.toBeUndefined;
    expect(output.toJSON()).not.toEqual(variation_b);
    // Cache has the selected variation
    expect(cacheStore.cache().length).not.toEqual(0);
    expect(cacheStore.cache()[experiment.name]).toEqual(output.toJSON().name);
  });
});