Slides for talk presented at OSDC 2008 in Sydney.

1. Automated Testing
with Ruby
Keith Pitty
Open Source Developers’ Conference, Sydney 2008
4th December

2. Once upon a time...

3. way back in 1983...

5. a young programmer made his way
from the world
of Unix at university...

7. to the world of
IBM mainframe programming.

9. He learnt to use such
weird and wonderful
technologies as...

10. PL/I, IMS, CICS, TSO and ISPF/PDF.

11. Fortunately he had a good mentor
who taught him about
modular programming...

12. and how to write unit tests with...

13. Job Control Language

14. “JCL is the stuff of nightmares for
many programmers and operators.”
From editorial review for “MVS JCL in Plain English”

15. fast forward to 2001

16. Our programmer was
not so young any more...

17. but he had moved on
from mainframe progamming...

18. to the exciting new world of Java...

19. and...

20. as a byproduct of
eXtreme Programming...

21. he had fallen in love with...

22. JUnit

23. He loved using JUnit to do
test-driven development
and refactoring...

24. and encouraged others to use it
whenever he had the opportunity.

25. fast forward to 2005

26. By now our hero had
begun to explore...

28. and...

30. He liked the way
tests were “baked in”
and how you could
run them with rake.

31. Then, one day in 2007,
a fellow Rails programmer
enquired...

32. “Are you using autotest?”

33. Sheepishly he admitted
he hadn’t even heard of it...

34. We’ll leave our story there for now.

35. Autotest

36. “a continuous testing facility
meant to be used during development.”

37. sudo gem install ZenTest
cd path/to/railsapp
autotest

38. “As soon as you save a file,
autotest will run the
corresponding dependent tests.”

39. Test::Unit

40. an implementation of xUnit

41. the default Ruby testing tool

42. distributed with Ruby since 2001

43. also the default testing tool for Rails

44. assert_kind_of BowlingAnalysis, @bowling_analysis
assert_equal quot;Brett Leequot;, @bowling_analysis.player.full_name
assert_equal quot;9.3quot;, @bowling_analysis.overs.to_s
assert_equal 1, @bowling_analysis.maidens
assert_equal 2, @bowling_analysis.wickets
assert_equal 50, @bowling_analysis.runs

45. Rails by default provides
unit, functional and integration tests

46. RSpec

48. RSpec allows you to specify behaviour

49. Specifying a model

50. describe Player do
before(:each) do
@valid_attributes = {
:first_name => quot;value for first_namequot;,
:last_name => quot;value for last_namequot;,
:active => true
}
end
it quot;should create a new instance given valid attributesquot; do
Player.create!(@valid_attributes)
end
end

51. Specifying a controller

52. describe PlayersController do
# missing code here will be revealed soon
it quot;should respond successfully to get 'index' with list of
playersquot; do
Player.should_receive(:find).and_return(@players)
get 'index'
response.should be_success
assigns[:players].should == @players
end
end

53. What makes a
good test?

55. 1. Isolated
2. Automated
Kent Beck suggests: 3. Quick to write
4. Quick to run
5. Unique

56. describe PlayersController do
before(:each) do
@player_1 = mock(Player, {:first_name => quot;Gregquot;,
:last_name => quot;Normanquot;,
:active => true})
@player_2 = mock(Player, {:first_name => quot;Adamquot;,
:last_name => quot;Scottquot;,
:active => true})
@players = [@player_1, @player_2]
end
it quot;should respond successfully to get 'index' with list of
playersquot; do
Player.should_receive(:find).and_return(@players)
get 'index'
response.should be_success
assigns[:players].should == @players
end
end

57. Mocks

58. Mocks mimic real objects

59. Mocks allow tests to be isolated

60. For more see “Mock Dialogue”
by Jim Weirich and Joe O’Brien

61. Other Mock
Frameworks

62. mocha
flexmock
rr

63. Autospec

64. Autospec rather than autotest
since RSpec 1.1.5

65. More on RSpec

66. Can also specify views
or
integrate views with controller specs

68. Integration
Testing

69. Can use Test::Unit
but I prefer...

70. Cucumber

72. A replacement for RSpec Story Runner

73. based on definition of
scenarios within features

74. Feature: Name of feature
In order to derive some business value
As a user
I want to take certain actions
Scenario: Name of scenario
Given a prerequisite
When I take some specific action
Then I should notice the expected outcome

75. cucumber
or
AUTOFEATURE=true autospec

76. can be used in conjunction with tools like
Webrat and Selenium

77. Webrat

78. simulates in-browser testing
by leveraging the DOM
without performance hit

79. Feature: Player belongs to group
In order for a player to be included
As a recorder
I want to record when a player joins or leaves
Scenario: Record when a new player joins
Given a player is not in the system
When I request a list of active players
And I follow quot;Add Playerquot;
And I fill in quot;player_first_namequot; with quot;Gregquot;
And I fill in quot;player_last_namequot; with quot;Normanquot;
And I press quot;Save Playerquot;
Then I should see quot;Active Playersquot;
And I should see quot;Greg Normanquot;

80. makes use of
Cucumber step definitions
for Webrat, for example...

81. When /^I follow quot;(.*)quot;$/ do |link|
clicks_link(link)
end
When /^I fill in quot;(.*)quot; with quot;(.*)quot;$/ do |field, value|
fills_in(field, :with => value)
end
When /^I press quot;(.*)quot;$/ do |button|
clicks_button(button)
end
Then /^I should see quot;(.*)quot;$/ do |text|
response.body.should =~ /#{text}/m
end

82. Selenium

83. • runs tests via a browser
• handles JavaScript

84. a little more effort than
just installing the Selenium gem

85. Feature: Check OSDC Site
In order to keep track of conference details
A participant
Should be able to browse the OSDC site
Scenario: Check the home page
Given I am on the OSDC home page
Then I should see the text quot;Welcome to the
Open Source Developers' Conferencequot;

86. require 'spec'
require 'selenium'
Before do
@browser = Selenium::SeleniumDriver.new(quot;localhostquot;,
4444, quot;*chromequot;, quot;http://localhostquot;, 15000)
@browser.start
end
After do
@browser.stop
end
Given /I am on the OSDC home page/ do
@browser.open 'http://www.osdc.com.au/'
end
Then /I should see the text quot;(.*)quot;/ do |text|
@browser.is_text_present(text).should == true
end

87. Fixtures

88. allow data for automated tests
to be defined using yaml

89. can be a pain to maintain

90. Machinist

91. Blueprints to generate
ActiveRecord objects

92. Hole.blueprint do
number 1
end
(1..18).each {|n| Hole.make(:number => n) }

93. Machinist with Sham

94. Sham.name { Faker::Name.name }
Sham.date do
Date.civil((2005..2009).to_a.rand,
(1..12).to_a.rand, (1..28).to_a.rand)
end
Player.blueprint do
first_name { Sham.name }
last_name { Sham.name }
active true
end
Round.blueprint do
date_played { Sham.date }
end

95. use blueprints in cucumber steps

96. now available as a gem on github

97. Other Tools

98. JavaScript
Unit Testing

99. Rails plugins:
javascript_test
javascript_test_autotest

100. js_autotest

101. see Dr Nic’s blog post

102. Shoulda

103. Extends Test::Unit
with the idea of contexts

104. Testing
Philosophy

105. How much effort
is warranted?

106. Is it taking
too much effort
to learn this
new testing tool?

107. My Opinion

108. Automated testing
can be viewed as a trade-off.

109. E <= ΔQ
Effort invested in automated tests
should result in at least
an equivalent improvement
in software quality.

110. I think it is worth striving
to continually improve my command
of automated testing tools...

111. always remembering
the business context.

112. Quotes

113. “Producing successful, reliable software
involves mixing and matching
an all-too-variable number
of error removal approaches,
typically the more of them the better.”
Robert L. Glass
Facts and Fallacies of Software Engineering

114. “Whether you are a hard-core
‘test first’ person is not the point.
The point is that everyone
can benefit from tests that are
automated, easy to write,
and easy to run.”
Hal Fulton
The Ruby Way

115. References

116. • Hal Fulton. The Ruby Way. Addison-Wesley, 2007
• Obie Fernandez. The Rails Way. Addison-Wesley,
2008
• David Chelimsky et al. The RSpec Book: Behaviour
Driven Development with Ruby. The Pragmatic
Programmers, 2009
• Robert L. Glass. Facts and Fallacies of Software
Engineering. Addison-Wesley, 2003

117. • http://zentest.rubyforge.org/ZenTest/
• http://rspec.info
• http://rubyhoedown2008.confreaks.com/02-joe-
obrien-and-jim-weirich-mock-dialogue.html
• http://www.infoq.com/news/2008/10/
qualities_good_test
• http://github.com/aslakhellesoy/cucumber

118. • http://github.com/brynary/webrat
• http://github.com/aslakhellesoy/cucumber/wikis/
setting-up-selenium
• http://github.com/notahat/machinist
• http://toolmantim.com/article/2008/10/27/
fixtureless_datas_with_machinist_and_sham

119. • http://drnicwilliams.com/2008/01/04/autotesting-
javascript-in-rails/
• http://www.thoughtbot.com/projects/shoulda
• http://pragdave.blogs.pragprog.com/pragdave/
2008/04/shoulda-used-th.html

120. Thanks for listening!
http://keithpitty.com