behat.yml

default:
    paths:
      features: src/Acme/MyBundle/Features
      bootstrap: %behat.paths.features%/bootstrap
    extensions:
        Behat\Symfony2Extension\Extension:
            mink_driver: true
            kernel:
              env: test
              debug: true
            bundle: AcmeMyBundle

        Behat\MinkExtension\Extension:
            default_session: symfony2

login.feature

Feature: Login system
    In order to access site's content
    As a user
    I want to login into the system

    Background:
        Given There is no "User" in database
        And the following users:
            | name  | password  | email         |
            | john  | john      | [email protected] |

    Scenario: User registration
        Given I am on "/register"
        Then I should see "Login"
        When I fill in the following:
         | Username      | my_user               |
         | Email         | [email protected]    |
         | Password      | my_password           |
         | Verification  | my_password           |
        And I press "Register"
        Then I should be on "/register/confirmed"