Making a page object class for use in feature tests

00_README.md

Feature tests can oftentimes get long, complicated, and hard to maintain. One common strategy that I use to break them apart is to use "page object classes". These classes may contain methods to find elements on the page, methods to interact with those elements, and methods to make assertions about what the user sees after those interactions are made.

This gist demonstrates what these page object classes look like. One thing to note is that Capybara methods like find and RSpec methods such as expect are automatically available in the class. This is made possible by having the class inherit from SimpleDelegator and then having the test pass self to the class initializer when an object is created. self is the context in which the test is running, and by receiving it, the page object can access method that the feature test can access. Now, there's a second way you could accomplish this: you could include RSpec::Matchers and Capybara::DSL instead of inheriting from SimpleDelegator. But this approach has one downside, which is applicable if you've configured RSpec to include custom modules in your feature tests. In this case, the functionality those modules provide won't be available in your page object class, because that class isn't a feature example group class.

01_page_object_class.rb

module Features
  class MyPageObjectClass < SimpleDelegator
    def some_container_element
      find(".whatever")
    end
    
    def expect_to_do_something
      expect(page).to have_css(".something")
    end
  end
end

02_feature_spec.rb

require "rails_helper"

feature "Some great feature" do
  scenario "Some awesome scenario" do
    my_page = Features::MyPageObjectClass.new
    
    within my_page.some_container_element do
      # do something
    end
    
    my_page.expect_to_do_something
  end
end