Mastering React Test-Driven Development

Streaming events with redux-saga

We'll repeat a lot of the same techniques in this section. There are two new concepts: first, pulling out the search param for the watcher ID, and second, using eventChannel to subscribe to the WebSocket onmessage callback:

1. Write a new describe block at the bottom of test/middleware/sharingSagas.test.js, but still nested inside the main describe block:

describe('watching', () => {  beforeEach(() => {    Object.defineProperty(window, 'location', {      writable: true,      value: {        host: 'test:1234',        pathname: '/index.html',        search: '?watching=234'      }    });  });  it('opens a socket when the page loads', () => {    store.dispatch({ type: 'TRY_START_WATCHING' });    expect(socketSpyFactory).toHaveBeenCalledWith( 'ws://test:1234/share' ...