user_login.feature

Feature: User login

  Scenario: User is greeted upon login
    Given a user with an account
    When he logs in
    Then he should be greeted

user_login.rb

module UserLoginSteps
  def create_user(user = FactoryGirl.build(:user))
    user.save_without_session_maintenance
    user
  end

  def login(user)
    visit login_path
    fill_in 'Email', :with => user.email
    fill_in 'Password', :with => user.password
    click_on 'Log in'
  end
end

World UserLoginSteps

RSpec::Matchers.define :be_greeted do
  match do |user|
    greeting_message = "Welcome, #{user.name}"
    page.has_content? greeting_message
  end

  failure_message_for_should do
    "expected the user to see a greeting message"
  end
end

user_login_steps.rb

Given /^a user with an account$/ do
  @user = create_user
end

When /^he logs in$/ do
  login @user
end

Then /^he should be greeted$/ do
  @user.should be_greeted
end

user_logout.feature

Feature: User logout

  Scenario: User is kicked off from his account upon logout
    Given a logged in user
    When he logs out
    Then he should be kicked off from his account

user_logout.rb

module UserLogoutSteps
  def logout(user)
    visit logout_path
  end
end

World UserLogoutSteps

RSpec::Matchers.define :be_kicked_off do
  match do |user|
    !UserSession.find && current_path != account_path
  end

  failure_message_for_should do |user|
    "expected the user to be kicked off from his account"
  end
end

user_logout_steps.rb

Given /^a logged in user$/ do
  @user = create_user
  login @user
end

When /^he logs out$/ do
  logout @user
end

Then /^he should be kicked off from his account$/ do
  @user.should be_kicked_off
end

Note that these scenarios are declarative and not imperative.