Record scenario screenshots for every step

[xurizaemon]

As a means to share step workflows with testers, I knocked together this extremely crude addition to ScreenshotContext this morning. It captures a screenshot of each step of a tagged scenario (probably erring on the side of too many screenshots, really), and means a tester can see the output frame by frame.

From here it would not be far to output a video artefact.

  use FeatureTrait, ScenarioTrait;

  /**
   * Record every step with a screenshot, if tagged with 'screenshot-vcr'.
   *
   * @AfterStep
   */
  public function recordStepScreenshots($event)
  {
    $tagName = 'screenshot-vcr';
    /** @var \Behat\Behat\Hook\Scope\BeforeStepScope $event */
    if (!$this->getScenario()->hasTag($tagName) && !$this->getFeature()->hasTag($tagName)) {
      return;
    }
    $driver = $this->getSession()->getDriver();
    $stepText = $event->getStep()->getText();
    $stepLine = $event->getFeature()->getFile() . '-' . $event->getStep()->getLine();
    $fileName = $this->makeFileName('html', preg_replace('/[^a-zA-Z0-9-]+/', '-', $stepLine . '-' . $stepText));
    try {
      $data = $driver->getContent();
    } catch (DriverException $exception) {
      // Do not do anything if the driver does not have any content - most
      // likely the page has not been loaded yet.
      return;
    }
    $this->saveScreenshotData($fileName, $data);
    try {
      $data = $driver->getScreenshot();
      // Preserve filename, but change the extension - this is to group
      // content and screenshot files together by name.
      $fileName = substr($fileName, 0, -1 * strlen('html')).'png';
      $this->saveScreenshotData($fileName, $data);
    } catch (UnsupportedDriverActionException $exception) {
      // Nothing to do here - drivers without support for screenshots
      // simply do not have them created.
    }
  }

Any thoughts on the approach @AlexSkrypnyk ? I'd love to contribute this in a way that makes sense alongside the rest of the project, or perhaps you know of existing solutions I'm not aware of.

Happy to turn into a PR if you want, but I don't feel it's at that level of quality yet 😁

[xurizaemon]

Closing for drevops/behat-screenshot#40 which is in the correct project.