Как вы тестируете omni -auth facebook с помощью rspec?

Я просмотрел вики gem и следовал инструкциям, но по какой-то причине я получаю nilпри выполнении теста omniauth:

user _сеансы _контроллер _spec.rb:

require 'spec_helper'

describe UserSessionsController, "OmniAuth" do
  before do
    request.env["omniauth.auth"] = OmniAuth.config.mock_auth[:facebook]
  end

  it "sets a session variable to the OmniAuth auth hash" do
    request.env["omniauth.auth"]['uid'].should == '123545'
  end
end

spec _helper.rb:

RACK_ENV = ENV['ENVIRONMENT'] ||= 'test'
OmniAuth.config.test_mode = true
omniauth_hash =
    {:provider => "facebook",
     :uid      => "1234",
     :info   => {:name       => "John Doe",
                 :email      => "johndoe@email.com"},
     :credentials => {:token => "testtoken234tsdf"}}

OmniAuth.config.add_mock(:facebook, omniauth_hash)

spec result:

Failures:

  1) UserSessionsController OmniAuth sets a session variable to the OmniAuth auth hash
     Failure/Error: request.env["omniauth.auth"]['uid'].should == '123545'
     NoMethodError:
       You have a nil object when you didn't expect it!
       You might have expected an instance of Array.
       The error occurred while evaluating nil.[]
     #./spec/controllers/user_sessions_controller_spec.rb:10:in `block (2 levels) in <top (required)>'