Designing End To End Test https://www.websequencediagrams.com/

designing_end_to_end_test.txt

title Designing End To End Test
Test->ApplicationRunner: perform_foobar_for(order)
ApplicationRunner->OrderPage: perform_action(Order::ACTION_FOOBAR)
OrderPage->CapybaraPage: visit('/orders/order.id')
OrderPage->CapybaraPage: click(text)
Test->ApplicationRunner: has_shown_foobar_status_for(order)
ApplicationRunner->OrderPage: shows_status(Order::STATUS_FOOBAR)
OrderPage->CapybaraPage: visit('/orders/order.id')
OrderPage->CapybaraPage: assert_text(text)

note left of Test
    Review of Concerns (reasons for change):
    
    * Test: when behaviour need be changed
    * ApplicationRunner: when application internal
      ...details changes, such as constant or new pages added
    * OrderPage: when order page UI need be changed
      ...or when capybara interface (DSL) changes

    What if we remove OrderPage?
    
    * application runner will need to know about UI
      and when UI change, it will need be changed in turn,
      thing will get more "interesting" with
      more objects/pages
      
    What if we remove ApplicationRunner?
    
    * test will need to know about order page and
      application details
      
    Excersice:
    
    Draw diagram for above cases,
    i.e. remove one or two collaborators and
    see how messages distributed between remainign objects
    asses concerns (reason for change) for each object
    compare results
end note

sample_spec.rb

# Sample Implementation with RSpec
describe "Orders Management", type: :feature, js: true do
  let(:application) { ApplicationRunner.new }
  let(:order) { Fabricate :order }

  it 'performs foobar on the order' do
    application.perform_foobar_for(order)
    expect(application).to have_shown_foobar_status_for order
  end

  # notice cohesion with page object "page_for"
  class ApplicationRunner
    def perform_foobar_for(order)
      page_for(order).perform_action Order::FOOBAR_ACTION
    end

    def has_shown_foobar_status_for?(order)
      page_for(order).shows_status Order::STATUS_FOOBAR
    end

    private

    def page_for(order)
      OrderPage.new(order)
    end

    # notice cohesion with capybara DSL "page"
    class OrderPage
      include Capybara::DSL

      def initialize(order)
        navigate_to order
      end

      def shows_status(text)
        # usually more complicated, i.e. with selectors, etc.
        page.assert_text text
      end

      def perform_action(name)
        page.click name
      end

      private

      def navigate_to(order)
        page.visit "/orders/#{order.id}"
      end
    end
  end
end