Drupal 8 BDD with Behat

behat.yml

default:
  suites:
    default:
      contexts:
        - FeatureContext
        - Drupal\DrupalExtension\Context\DrupalContext
        - Drupal\DrupalExtension\Context\MinkContext
        - Drupal\DrupalExtension\Context\MessageContext
        - Drupal\DrupalExtension\Context\DrushContext
        - NuvoleWeb\Drupal\DrupalExtension\Context\AutocompleteContext
  extensions:
    DMore\ChromeExtension\Behat\ServiceContainer\ChromeExtension: ~
    Behat\MinkExtension:
      goutte: ~
      default_session: goutte
      javascript_session: default
      browser_name: chrome
      base_url: "http://localhost:8888"
      sessions:
        default:
          chrome:
            api_url: "http://localhost:9222"
    Bex\Behat\ScreenshotExtension:
      screenshot_taking_mode: failed_steps
      image_drivers:
        local:
          screenshot_directory: ./features/screenshots
          clear_screenshot_directory: true
    NuvoleWeb\Drupal\DrupalExtension:
      blackbox: ~
      api_driver: drupal
      drupal:
        drupal_root: .

contact-form.feature

# Located at ./features/

Feature: Contact form
  In order to send a message to the site administrators
  As a visitor
  I should be able to use the site-wide contact form

  Scenario: A visitor can use the site-wide contact form
    Given I am at "contact/feedback"
    When I fill in the "name" field with "John Doe"
    And I fill in the "email address" field with "[email protected]"
    And I fill in the "subject" field with "Hello world"
    And I fill in the "message" field with "Lorem Ipsum"
    And I press "Send message"
    Then I should see the text "Your message has been sent."

  @api
  Scenario: A authenticated can use the site-wide contact form
    Given I am logged in as a user with the "Authenticated user" role
    And I am at "contact/feedback"
    And I should not see the "name" field
    And I should not see the "email address" field
    And I fill in the "subject" field with "Hello world"
    And I fill in the "message" field with "Lorem Ipsum"
    And I press "Send message"
    Then I should see the text "Your message has been sent."

create-article.feature

# Located at ./features/

Feature: Article administration
  In order administer articles
  As an administrator
  I should be the proper permissions

  @api @javascript
  Scenario: An administrator can create an article
    Given I am logged in as a user with the "Administrator" role
    And I am at "node/add/article"
    When I fill in "Title" with "Tofu is the best"
    And I fill in the autocomplete "Tags" with "Vegan"
    And I press "Save"
    Then I should see the text "Article Tofu is the best has been created."
    And I should see the text "Vegetarian"

FeatureContext.php

<?php

use Behat\Mink\Exception\ExpectationException;
use Behat\MinkExtension\Context\RawMinkContext;

// Located at ./features/bootstrap/

/**
 * FeatureContext class defines custom step definitions for Behat.
 */
class FeatureContext extends RawMinkContext
{
    /**
     * Initializes context.
     *
     * Every scenario gets its own context instance.
     * You can also pass arbitrary arguments to the
     * context constructor through behat.yml.
     */
    public function __construct()
    {
    }

    /**
     * @When I fill in the :arg1 field with :arg2
     */
    public function iFillInTheFieldWith($name, $value)
    {
      $selector = $this->getFieldSelector($name);
      $field = $this->fixStepArgument($selector);
      $value = $this->fixStepArgument($value);
      $this->getSession()->getPage()->fillField($field, $value);
    }

    /**
     * @Given I should not see the :name field
     */
    public function iShouldNotSeeTheField($name)
    {
      $selector = $this->getFieldSelector($name);
      $field = $this->fixStepArgument($selector);
      $element = $this->getSession()->getPage()->findField($field);
      if ($element) {
        throw new ExpectationException(sprintf("The field '%s' was present on the page %s and was not supposed to be", $element, $this->getSession()->getCurrentUrl()), $this->getSession());
      }
    }
  
    /**
     * Returns selector for specified field/
     *
     * @param string $field
     *
     * @return string
     */
    protected function getFieldSelector($field) {
      $selector = $field;
  
      switch ($field) {
        case 'email address':
          $selector = 'mail';
          break;
  
        case 'subject':
          $selector = 'subject[0][value]';
          break;
  
        case 'message':
          $selector = 'message[0][value]';
          break;
      }
  
      return $selector;
    }
  
    /**
     * Returns fixed step argument (with \\" replaced back to ")
     *
     * @param string $argument
     *
     * @return string
     */
    protected function fixStepArgument($argument)
    {
      return str_replace('\\"', '"', $argument);
    }
}