@jetshop/core/experiments/useExperiment.test.js

import React from 'react';
import { render, cleanup } from '@testing-library/react';
import useExperiment from './useExperiment';
import { StaticRouter } from 'react-router';
import { CookiesProvider } from 'react-cookie';
import Cookies from 'universal-cookie';
import ExperimentsProvider from './ExperimentsProvider';
import AnalyticsProvider from '../analytics/AnalyticsProvider';
import { ConfigProvider } from '../components/ConfigProvider';
import { ChannelProvider } from '../components/ChannelContext';
import { ChannelHandler } from '../ChannelHandler/ChannelHandler';
import { selectedChannel, channels } from '../test-utils/variables';
import { HelmetProvider } from 'react-helmet-async';
afterEach(cleanup);

const Collector = ({ report, id, variant }) => {
  const data = useExperiment(id, variant);
  report(data);
  return null;
};

const setup = ({ report, id, variant, cookies }) => {
  const channelHandler = new ChannelHandler({
    selectedChannel,
    channels
  });
  return render(
    <StaticRouter>
      <CookiesProvider cookies={cookies}>
        <HelmetProvider context={{}}>
          <ChannelProvider channelHandler={channelHandler}>
            <ConfigProvider config={{}}>
              <AnalyticsProvider config={{}}>
                <ExperimentsProvider>
                  <Collector report={report} id={id} variant={variant} />
                </ExperimentsProvider>
              </AnalyticsProvider>
            </ConfigProvider>
          </ChannelProvider>
        </HelmetProvider>
      </CookiesProvider>
    </StaticRouter>
  );
};

describe('useExperiment', () => {
  it('returns false if no cookie is set', () => {
    const cookies = new Cookies({});

    const report = jest.fn();
    setup({
      cookies,
      report,
      id: null,
      variant: null
    });

    expect(report).toHaveBeenCalledTimes(1);
    expect(report).toHaveBeenCalledWith(false);
  });

  it('returns false if cookie does not match provided experiment and variant', () => {
    const cookies = new Cookies({
      optimizeExperiment: 'test.0'
    });
    const report = jest.fn();
    setup({
      cookies,
      report,
      id: 'test',
      variant: 1
    });

    expect(report).toHaveBeenCalledTimes(1);
    expect(report).toHaveBeenCalledWith(false);
  });

  it('returns true if cookie matches provided experiment and variant', () => {
    const cookies = new Cookies({
      optimizeExperiment: 'test.0'
    });
    const report = jest.fn();
    setup({
      cookies,
      report,
      id: 'test',
      variant: 0
    });

    expect(report).toHaveBeenCalledTimes(1);
    expect(report).toHaveBeenCalledWith(true);
  });
});