Use a Service Worker for your e2e testing

See the build in CircleCI

Test network activity using ServiceWorker and Selenium.

Bugs in network activity are hard to find before its too late. Here I'm about to share with you a non intrusive method for asserting on network request natively in the browser using Selenium and Service-Workers.

An example test

describe('Tracking requests', () => {
  it('Ad view tracking', () => {
    browser.url('/')
    browser.waitUntil(() => {
      const recordedRequests = this.browser.execute(() => {
        return window.__e2eFetchRequests
      }).value

      const trackingRequests = recordedRequests.map(request => {
        return request.url.indexOf('https://mytrackingservice.com/my/tracking/request')
      })
      return trackingRequests && trackingRequests.length === 1
    }, 2000, 'Must send tracking request', 200)
  })
})