Acceptance Tests with Capybara

How and why we should write Acceptance Tests, with Capybara, for our Ruby/Rails web applications.

Transcript

1. Brian Hughes @brianvhughes What’s a Capybara?
2. Largest of all living rodents. Master of the Grasses! What’s a Capybara?
3. What is Capybara?
4. Ruby Acceptance Test framework for Rack-based web applications What is Capybara?
5. Ruby Acceptance Test framework for Rack-based web applications What is Capybara?
6. What’s an Acceptance Test?
7. What’s an Acceptance Test? Verify the functionality of your web app, from a user’s POV
8. Did we really need another kind of test?
9. Did we really need another kind of test?
10. Did we really need another kind of test? “Unit” tests Model specs Model Layer
11. Did we really need another kind of test? “Unit” tests Model specs Model Layer “Functional” tests Controller specs Controller Layer
12. Did we really need another kind of test? “Unit” tests Model specs Model Layer “Functional” tests Controller specs Controller Layer View tests/specs View Layer
13. Did we really need another kind of test? “Unit” tests Model specs Model Layer “Functional” tests Controller specs Controller Layer Route tests/specs Route Layer View tests/specs View Layer
14. Did we really need another kind of test? “Unit” tests Model specs Model Layer “Functional” tests Controller specs Controller Layer Route tests/specs Route Layer View tests/specs View Layer
15. Testing behavior from the developer’s PoV
16. Users don’t think like developers.
17. Users receive value from our apps.
18. User Value in Web Apps? Lives in the Web Browser Delivered via HTML, CSS, JavaScript Rendered as pages, links, forms, buttons Derived through interactions with these elements.
19. How do we verify that value is delivered? Hint: CMD-R in Safari/Chrome is not the answer.
20. Acceptance Tests with Capybara
21. Acceptance Tests with Capybara Provides methods to automate browser interactions Can drive both headless and GUI browsers Integrates with RSpec, TestUnit and Cucumber Lets us test drive our web apps “outside-in”
22. How do we write Acceptance tests? What’s the role of the user? What feature do they want to access? How does the user verify success? What are the browser steps that perform the feature? What’s the starting state of our app?
23. How do we write Acceptance tests? What’s the role of the user? What feature do they want to access? How does the user verify success? What are the browser steps that perform the feature? What’s the starting state of our app?
24. User Stories
25. User Stories Describe a single feature/function of the application The user’s PoV. State a goal and describe the feature needed for success. “As a <user_role>”, “In order to accomplish <goal>”, “I need to perform <new_feature>”. Defines the parameters for writing and verifying an Acceptance Test
26. User Story Example Voting for a Topic As an LVRUG Member In order to indicate that I want to see “Topic A” presented I want to vote for “Topic A”, so it rises higher in the Most Votes list
27. User Story Example Suggesting a Topic As an LVRUG Member In order to learn cool stuff I want to suggest a topic for members to vote on
28. User Story Example Assigning Presenter Bonus Points As an LVRUG Organizer In order to encourage more 1st time topic volunteers When a 1st time volunteer presents a topic, they should receive 10 extra bonus points.
29. Use the Story definition to help describe the Acceptance Test
30. But what about Capybara?
31. But what about Capybara? Drives a Browser to interact with your app Can visit URL paths and follow/click links Interacts with form fields and clicks buttons Can search HTML text via CSS and XPath Provides matchers to verify the presence of HTML elements and content
32. But what about Capybara? Provides a headless Rack App HTML browser Also supports Selenium web driver, for JavaScript interactions Can integrate with capybara-webkit gem, to have headless HTML + JavaScript browsing. Will use Launchy gem to save HTML as a rendered page for browser viewing
33. RSpec + Capybara Example Voting for a Topic As an LVRUG Member In order to indicate that I want to see “Topic A” presented I want to give my “vote” to Topic A, so that it has more votes than Topic B
34. RSpec + Capybara Example
35. RSpec + Capybara Example
36. RSpec + Capybara Example Suggesting a Topic As an LVRUG Member In order to learn cool stuff I want to suggest a topic for members to vote on
37. RSpec + Capybara Example
38. RSpec + Capybara Example
39. RSpec + Capybara Example
40. Capybara Resources https:/ /github.com/jnicklas/capybara https:/ /github.com/thoughtbot/capybara- webkit https:/ /github.com/copiousfreetime/launchy https:/ /github.com/jonleighton/poltergeist http:/ /www.elabs.se/blog/51-simple-tricks-to- clean-up-your-capybara-tests