Feature Testing

Capybara & Sinatra

Warmup

• What are we testing so far in our FilmFile app?
• What aren’t we testing?
• Assuming that our tests will have some setup, executation, assertions, and teardown, what might be included in each phase?

Feature Tests

• Mimic the behavior of the user
• Shouldn’t have to know about underlying code
• Based on user stories

User Stories

• As a user
• When I visit the home page
• And I fill in title
• And I fill in description
• And I click submit
• Then my task is saved

User Stories

• As a user
• When I visit the home page
• And I fill in title
• And I fill in description
• And I click submit
• Then I see a page with my task on it

User Stories

• As a [user/user-type]
• When I [action]
• And I [action]
• And I [action]
• And I [action]
• Then I [action]

Create User Stories

• Adding a Film to FilmFile
• Viewing only the Films associated with a specific Genre
• Signing up for a new account
• Logging into an account

Capybara

• Test Framework
• Allows you to test any rack-based app
• Used for feature tests
• Helps you query and interact with the DOM

Capybara Methods

• visit(‘path’)
• expect(page).to have_content(“Content”)
• expect(page).to have_css(“CSS”)
• within(“CSS”) {Expectations or Actions}

Highlighted item are intended to change based on the actual example.

In Code

describe "When a user visits a film show page" do
  it "they should see information about the film" do
    film = Film.create(title: "Fargo", year: 2017, box_office_sales: 4)

    visit "/films/#{film.id}"

    within "#description" do
      expect(page).to have_content("Fargo")
    end
  end
end

Setup & First Test

On your own or with a partner:

• Follow the instructions in the lesson plan to set up your first feature test
• Try to see if you can create a test and make it pass

Share

Launchy

• Gem that allows us to open a page in the middle of a test
• In your Gemfile: gem 'launchy'
• When you want to use in your test: save_and_open_page

Forms & Buttons

• fill_in(“identifier”, with: “content”)
• click_link(“identifier”)
• click_button(“identifier”)
• click_link_or_button(“identifier”)
• click_on(“identifier”)
• expect(current_path).to eq(“identifier”)

Workshop

Write Feature Tests For:

• The process of creating a Film
• That all films are displayed on the Film index
• That a Genre’s total winnings are displayed on their page

When do I write a feature test?

• Opinions vary
• To help drive development
• To ensure user stories are functioning
• To ensure user stories continue to function
• If it’s important and you don’t want it to break, test it

Takeaways

• Feature tests mimic user behavior
• User stories help us figure out what to put in a feature test
• Capybara allows us to
  • interact with a page
  • interpret results in our tests
• Launchy helps us debug