title: CucumberJS/Protractor screenshot comparison after each step
body: <p>I integrated CucumberJS with Protractor to write E2E tests for an <strong>Angular</strong> (not AngularJS) application.
  Is there any easy way (maybe an already existing package) to take screenshots after each step (Given, When, Then) and compare them with some reference images? If reference images are not present, then to register the screenshot as a reference image.
  The step should fail if the images are too different.</p>
  <p>Before asking this question I read <a href="https://stackoverflow.com/questions/40832067/cucumberjs-take-screenshot-after-each-step">CucumberJS: Take screenshot after each step</a>, but that question is about taking a screenshot, not comparing.</p>