Rspec integration signing in with Devise LDAP

So I'm trying to create integration tests for my rails 4.0 application, and I'm unsure how to authorize users (the application uses devise_ldap_authenticatable.

Initally, I attempted:

  setup do
    sign_in User.find_by_login('john.smith')
  end

  teardown do
    sign_out
  end


  test "can see index page" do
    get "/"
    assert_select "table[id=?]", "main_table"
  end

Which I can do inside normal rails code. However, this doesn't work. I then found this question, which provided answers for both controller and integration testing.

However, the problem is that the integration testing example:

post_via_redirect Rails.application.routes.url_helpers.user_session_path, 'user[email]' => user.email, 'user[password]' => user.password

Is for basic Devise, and doesn't take into account the use of an LDAP server (which therefore means I do not store passwords).

Does anyone know how to do integration tests when an LDAP server is involved, and login are required?