Scenario: Create album
  Given I am logged in as "pepito"
  When I go to my profile page
  ...

Given /^the user (.*) exists$/ do |login_name|
  User.find_by_login(login_name) || Factory(:user_with_password, :login => login_name)
end

Given /^I log in as (.*)$/ do |login_name|
  user = User.find_by_login(login_name)
  # it is supposed that the user was generated by the :user_with_password fixture
  # that has the 'secret' password
  post "/session", :login => user.login, :password => 'secret'
end

Given /^I am logged in as "(.*)"$/ do |login_name|
  Given "the user #{login_name} exists"
  Given "I log in as #{login_name}"
end

When /^I go to (.+)$/ do |page_name|
  visit path_to(page_name)
end

def path_to(page_name)
  case page_name

  when /my profile page/i
    member_profile_path(:id => session[:user_id])

  ...
end

When I go to my profile page  # features/step_definitions/webrat_steps.rb:6
  You have a nil object when you didn't expect it!
  The error occurred while evaluating nil.session (NoMethodError)
     /usr/local/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_controller/test_process.rb:429:in `session'