Cucumber steps - testing a repository

I have a stateless EJB that uses @PersistenceContext with a EntityManager, I'm writing a cucumber step definitions class that uses this repository to perform steps in testing finding users based upon supplied criteria.

So for example

@Stateless
public class UserRepository {

    @PersistenceContext
    private EntityManager em;

    public void add(String userName) {
        User user = new User(userName);
        em.persist(user);
    }    

    public List<User> findByName(String userName) {
        return em.createQuery("Select u from User as u WHERE u.name LIKE :userName").setParameter("userName", userName).getResultList();
    }

}

And a feature file that looks something like

Feature: Search

    Given a user with the name 'Jason Statham'
        And another user with the name 'Bill Gates'
        And another user with the name 'Larry Page'
    When the customer searches for a user with the name 'Jason'
    Then 1 users should have been found
        And User 1 should have a name of 'Jason Statham'

And a steps definition class

public class SearchStepsDefinitions {

   private List<User> userList = new ArrayList<>();
   private UserService userService = new UserService();

   @Given(value = ".+user with the name '(.+)'$")
   public void a_user_with_the_name(final String userName) {
       userService.add(userName);
   }

   @When(value = "^the customer searches for a user with the name '(.+)'$")
   public void the_customer_searches_for_a_user_with_the_name(final String name) {
       userList = userService.findByName(name); 
   }

   @Then(value = "(\\d+) users should have been found$")
   public void users_should_have_been_found(final int userCount) {
       assertThat(userList.size(), equalTo(userCount));
   }

   @Then(value = "User (\\d+) should have a name of '(.+)'$")
   public void should_have_a_name_of(final int position, final String name) {
       assertThat(userList.get(position - 1).getName(), equalTo(name)); 
   }

}

Now I understand that as the Repository is an EJB the EntityManager is injected via the @PersistenceContext.

My question is in the steps definition how should I be dealing with this dependency? Should I be mocking it and injecting this mock into the UserRepository, or should the UserRepository have a setter for the EntityManager and use a EntityManagerFactory to create one in the SearchStepsDefinitions?