given_when_then

group :test do
  gem 'given_when_then'
  # ...
end

bundle

describe 'Signing up' do
  Given 'there is a guest user' do
    let(:user) { stub('user', :name => 'Mr XY', :email => 'xy@example.com', :password => 'secret' ) }

    When 'he goes to the home page' do
      before { visit root_path }

      Then 'he should see the navigational links' do
        page.should have_content 'Sign up or Log in'
      end

      When 'he clicks the Sign up link' do
        before { visit signup_path }

        Then 'he should be presented with a signup form' do
          page.should have_selector 'div[id="signup_form"]'
        end

        When 'he clicks the Sign up button without filling in his credentials' do
          Then 'he should see an error message' do
            click_button 'Sign up'
            page.should have_content('errors prohibited')
            User.count.should == 0
          end

          And 'the path to the form should be the signup_path (see routes.rb)' do
            current_path.should == signup_path
          end
        end

        When 'he fills the form with his credentials and clicks the Sign up button' do
          before do
            fill_in 'Name', :with => user.name
            fill_in 'Email', :with => user.email
            fill_in 'Password', :with => user.password
            fill_in 'Confirm Password', :with => user.password
            click_button 'Sign up'
          end

          Then 'he should be signed up successfully' do
            page.should have_content('Signed up!')
            current_path.should == root_path
            User.count.should == 1
          end
        end
      end
    end
  end
end

Signing up
  Given there is a guest user
    When he visits the home page
      Then he should see the navigational links
      When he clicks the Sign up link
        Then he should be presented with a signup form
        When he clicks the Sign up button without filling in his credentials
          Then he should see an error message
          And the path to the form should be the signup_path (see routes.rb)
        When he fills the form with his credentials and clicks the Sign up button
          Then he should be signed up successfully