Talk given by Joseph Wilk at Scotland on Rails 2009. Examines how Cucumber and Rspec fit together in the testing workflow, how and why Cucumber is useful and how it works. Walks through a simple example based on renting DVDs showing how to use Cucumber and some of the best practices. Looks at how Webrat can drive Selenium to in-turn drive Cucumber features through the browser.

1. utside
in
Development
Cucumber Rspec
Joseph Wilk / http://blog.josephwilk.net

2. Why are you here?

3. Why are you here?
In order to ...

4. Why are you here?
In order to ...
As a Scotland on Rails attendee

5. Why are you here?
In order to ...
As a Scotland on Rails attendee
I want ...

6. What is your
Acceptance Criteria?

7. Scenario: Happy SoR attendees
Given people turned up
When Joseph talks
Then everyone should acquire some new knowledge
And no-one should fall asleep
And no rotten food should be thrown

8. Pass
Fail

9. Outside-in
User
Browser
Views
Controllers
Models

10. Cucumber
“The feature
you wished you
had” Views
Controllers
Rspec
Models “The
components
and the
interactions
you wish you
had”

11. Cucumber
“The feature
you wished you
had” Views
Controllers
Rspec
Models “The
components
and the
interactions
you wish you
had”

12. Cucumber
“The feature
you wished you
had” Views
Controllers
Rspec
Models “The
components
and the
interactions
you wish you
had”

13. Cucumber / Scenario

14. Cucumber / Scenario

15. Cucumber / Scenario
Rspec / code
examples

16. Cucumber / Scenario
Rspec / code
examples

17. Cucumber / Scenario
Rspec / code
examples

18. Cucumber / Scenario
Rspec / code
examples

19. Cucumber / Scenario
Rspec / code
examples

20. :rspec => route finder
:cucumber => destination
London Edinburgh

21. Behaviour Driven Development
with elegance and joy

22. Behaviour Driven Development
with elegance and joy
Just Cuke it!

23. Plaintext Ruby
Features step definitions

24. Cucumber Feature
Not
executed
Feature: Be awesome
Narrative
Scenario: title Example of
Given <some context> behaviour
And <yet more context>
When <some action>
And <more actions>
Then <some outcome>
And <more outcomes>

25. regexp match
Step
definition
Given /^we like (.*)$/i do |fruit|
fruit.should == 'cukes'
Ruby tests #assert_equal(fruit, 'cukes')
end
Plaintext Given we like cukes
Feature
Cucumber

26. Plug and Pray
Rspec
Plaintext Ruby tests
TestUnit
Cucumber
Ruby-Gnome2 Cucumber
Sinatra
Rails Merb iPhone

27. Cucumber English

28. огурец Russian Chinese
concombre French Korean
gurka Swedish
Japanese
German castravete Romanian
Gurke
ogórek
Cucumber English Polish
pepino Spanish
Italian
cetriolo
Danish
agurk
‫ﺍﳋﻴﺎﺭ‬ Arabic
Indonisean
ketimun

29. огурец Russian Chinese
concombre French Korean
gurka Swedish
Japanese
German castravete Romanian
Gurke
ogórek
Cucumber English Polish
pepino Spanish
Treetop Rocks
Italian
cetriolo
ANTLR
Danish
agurk
could rock
‫ﺍﳋﻴﺎﺭ‬ Arabic
Indonisean
harder
ketimun

30. Webrat
Love
visit home_path
click_link quot;Webquot;
fill_in quot;Emailquot;, :with => quot;Rat”
click_button quot;Lovequot;
Bansky

31. Return On Investment
Cucumber Feature

32. Return On Investment
Cucumber Feature
• Token Conversation

33. Return On Investment
Cucumber Feature
• Token Conversation
• Acceptance Criteria

34. Return On Investment
Cucumber Feature
• Token Conversation
• Acceptance Criteria
• Design

35. Return On Investment
Cucumber Feature
• Token Conversation
• Acceptance Criteria
• Design
• Documentation

36. Return On Investment
Cucumber Feature
• Token Conversation
• Acceptance Criteria
• Design
• Documentation
• Functional test

37. Return On Investment
Cucumber Feature
• Token Conversation
• Acceptance Criteria
• Design
• Documentation
• Functional test
• Integration test

38. Token for Conversation

40. Feature Request
I want members to be able to
rent a movie with a priority
indicating how much they
want to see the film

41. Show me the _ _ _ _ _

42. Show me the VA L U _
____E

43. Root Cause Analysis

44. Root Cause Analysis
Why? So we can maximise allocation of
films

45. Root Cause Analysis
Why? Keep customers happy
Why? So we can maximise allocation of
films

46. Root Cause Analysis
Why? So they continue with their
subscriptions
Why? Keep customers happy
Why? So we can maximise allocation of
films

47. Root Cause Analysis
Why? So they continue with their
subscriptions
Why? Keep customers happy
Why? So we can maximise allocation of
films

48. Lets write our
Cucumber feature

49. Feature (terrible)
Value
Feature: select a movie to rent with priority
In order to maximise allocation of films
The website user
Needs to be able to add movies to their rental list with a priority
Role Feature

50. Feature (terrible)
Value
Feature: select a movie to rent with priority
In order to maximise allocation of films
Narrative
The website user
Needs to be able to add movies to their rental list with a priority
Role Feature

51. Feature (terrible)
Value
Feature: select a movie to rent with priority
In order to maximise allocation of films
The website user
Needs to be able to add movies to their rental list with a priority
Role Feature

52. Feature (terrible)
Feature: select a movie to rent with priority
In order to maximise allocation of films
The website user
Needs to be able to add movies to their rental list with a priority

53. Feature (terrible)
Feature: select a movie to rent with priority
In order to maximise allocation of films
The website user
Needs to be able to add movies to their rental list with a priority
Noise

54. Feature (terrible)
Feature: select a movie to rent with priority
In order to maximise allocation of films
The website user
Needs to be able to add movies to their rental list with a priority
Too generic
role

55. Feature (terrible)
Feature: select a movie to rent with priority
In order to maximise allocation of films
The website user Film member
Needs to be able to add movies to their rental list with a priority
Too generic
role

56. Feature (terrible)
Role can change
feature
Feature: select a movie to rent with priority
In order to maximise allocation of films
The website user Film member
Needs to be able to add movies to their rental list with a priority

57. Feature (terrible)
Role can change
feature
Film Member selects a movie to rent with priority
Feature: select a movie to rent with priority
In order to maximise allocation of films
The website user Film member
Needs to be able to add movies to their rental list with a priority

58. Nice
Feature (terrible)
Film Member selects a movie to rent with priority
Feature: select a movie to rent with priority
In order to maximise allocation of films
The website user Film member
Needs to be able to add movies to their rental list with a priority

59. Acceptance
Definition of Done.

60. Scenarios
Feature: Film Member selects a movie to rent with priority
In order to maximise allocation of films
The Film member
Needs to add movies to their rental list with a priority
Scenario: High priority

61. Scenarios
Feature: Film Member selects a movie to rent with priority
In order to maximise allocation of films
The Film member
Needs to add movies to their rental list with a priority
Scenario: High priority
Then I should see quot;My rental listquot;
And I should see quot;Casshernquot; in my rental list
And quot;Casshernquot; should be marked as quot;High priorityquot;

62. Scenarios
Feature: Film Member selects a movie to rent with priority
In order to maximise allocation of films
The Film member
Needs to add movies to their rental list with a priority
Scenario: High priority
When I choose quot;High priorityquot;
And I press quot;Rentquot;
Then I should see quot;My rental listquot;
And I should see quot;Casshernquot; in my rental list
And quot;Casshernquot; should be marked as quot;High priorityquot;

63. Scenarios
Feature: Film Member selects a movie to rent with priority
In order to maximise allocation of films
The Film member
Needs to add movies to their rental list with a priority
Scenario: High priority
Given I'm logged in
And I am viewing the movie quot;Casshernquot;
When I choose quot;High priorityquot;
And I press quot;Rentquot;
Then I should see quot;My rental listquot;
And I should see quot;Casshernquot; in my rental list
And quot;Casshernquot; should be marked as quot;High priorityquot;

65. Let there be Cuking

66. Demo
High Resolution:
http://www.screencast.com/t/aG1sE4N3Zq
Low Resolution:
http://www.vimeo.com/3910617

67. Here’s one I
Cuked earlier

68. Demo
High Resolution:
http://www.screencast.com/t/tlBYxkKci
Low Resolution
http://www.vimeo.com/3911104

69. Installing Cucumber
$ sudo gem install cucumber
$ script/plugin install git://github.com/aslakhellesoy/
cucumber.git
$ gem sources -a http://gems.github.com
$ sudo gem install aslakhellesoy-cucumber

70. Fixtures
Scenario: search results found Given /^the Movies$/i do |movie_hash|
Given the Movies #{:title => quot;The colour whitequot;},
| title | #{:title => quot;The colour redquot;},
| The colour white | #{:title => quot;Casshernquot;}
| The colour red | movies.hashes.each do |values|
| Casshern | Movie.create!(values)
When I search for quot;colourquot; end
Then I will see 2 results end
Scenario: search results found
Given 2 films with quot;colourquot; in the title
When I search for quot;colourquot;
Then I will see 2 results

71. Stick it to the World
module NavigationHelpers
def path_to(page_name)
case page_name
when /the homepage/
root_path
else
raise quot;Can't find mapping from quot;#{page_name}quot; to a path.quot;
end
end
end
World do |world|
world.extend NavigationHelpers
world
end

72. Hooks
Hooks are GLOBAL!
Before do
# do something before each scenario.
end
After do
#do something after each scenario
end

73. How many scenarios is
enough?
• Given/When/Then
“Finite state machine” Uncle Bob
• What’s the Return on Investment?

74. Cowcumbers (Bad smells)
“fit only for consumption by cows”

75. Cowcumbers
Given /^dirty state$/ do
@movie = Movie.create!
Relying on state (too much) end
Given /^coupled by state$/ do
@movie.title = quot;yuckyquot;
end
Given /^does a user care$/ do
response.current_url == ‘silly’
end
Tests without user value Given /^checking the db$/ do
Movie.find(1).should_not == nil
end

76. Building your DSL

77. Concrete vs Abstract
Scenarios
Given I'm logged in
Given I go to the login page
And I fill in quot;usernamequot; with quot;josephquot;
And I fill in quot;passwordquot; with quot;cukerquot;
And I click quot;loginquot;
Domain understanding
Concrete Abstract

78. Calling steps from steps
Given /I’m logged in/ do
User.create!(:user => 'josephwilk', :password => quot;passquot;)
Given 'I fill in quot;passwordquot; with quot;josephwilkquot;'
Given 'I fill in quot;passwordquot; with quot;passquot;'
Given 'I click quot;loginquot;'
end

79. Feature Request
Can you add some of that
funky AJAX stuff for the
rent button

80. JavaScript kills Webrat

81. Watir, Selenium &
Celerity
Browser based Headless Browser
• •
Watir Celerity
• •
Selenium Culerity - http://
github.com/langalex/
culerity/tree/master

82. Webrat / Selenium
# Sets up the Rails environment for Cucumber
ENV[quot;RAILS_ENVquot;] ||= quot;seleniumquot;
require File.expand_path(File.dirname(__FILE__) + '/../../config/environment')
require 'cucumber/rails/world'
require 'cucumber/formatters/unicode'
Turn off
#Cucumber::Rails.use_transactional_fixtures
require 'webrat'
Webrat.configure do |config|
Switch to Selenium
config.mode = :selenium
end
require 'cucumber/rails/rspec'
require 'webrat/core/matchers'
Before do
Movie.delete_all
Manually cleanup
RentalRequest.delete_all
end

83. Organising
@in-progress
Feature: Verify billing
Tag @js
Scenario: Missing product description
Scenario: Several products
cucumber --profile rails --tags ~@js
cucumber --profile browser --tags @js

84. Demo
High Resolution:
http://www.screencast.com/t/1jRSI6TvXWu
Low Resolution:
http://www.vimeo.com/3911241

85. Further reading
• http://cukes.info
• http://wiki.github.com/
aslakhellesoy/cucumber
• http://rspec.info/
• http://blog.josephwilk.net

86. Thanks
joe@josephwilk.net
http://github.com/josephwilk