The slides for my presentation at GeekCamp.sg 2009.

1. A LAZY Developer's
Guide to BDD
(with )
~ Ng Tze Yang (aka TY)

2. 2 weeks ago, i changed it to:
Everyone gets a little
of 's ♥
2

3. A LAZY Developer's
Guide to BDD
(with )
3

4. WTF is “LAZY” ??
4

5. LAZY= !(TATFT)
5

6. WTF is “TATFT” ??
6

7. 7

8. Why Not TATFT ??
8

9. Why Not TATFT ??
* What is most important for a
software ??
9

10. Why Not TATFT ??
* What is most important for a
software ??
=> Business Value
10

11. Why Not TATFT ??
* What is most important for a
software ??
=> Business Value
* How do we quantify BV ??
11

12. Why Not TATFT ??
* What is most important for a
software ??
=> Business Value
* How do we quantify BV ??
=> Behaviours
12

13. BDD
~ Behaviour Driven Development ~
13

14. BDD
~ Behaviour Driven Development ~
“BDD facilitates agile development,
which is an approach to develop functional
software, within reasonable timeline, making
everyone happy, without killing anyone, or
burning down any bank.”
14

15. BDD's Core Principles
15

16. BDD's Core Principles
* It's all behaviour
“ The business & technology people
should be speaking the same words
when referring to the same idea,
there should not be any translator.”
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17. BDD's Core Principles
* It's all behaviour
Behaviour: the addition of N values
should yield the summation of them
Example: the addition of 2 + 4 +1
should yield 8
17

18. BDD's Core Principles
* It's all behaviour
* Deliver stakeholder value
“ Whatever u are doing, it should be
delivering business value, or increasing
ur ability to deliver value, if the activity
doesn't acheive this, stop doing it”
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19. BDD's Core Principles
* It's all behaviour
* Deliver stakeholder value
“ Unit testing is important, as it makes
refactoring & regression testing easier, which
eases maintenace and enhance ur ability to
deliver newer features faster”
19

20. BDD's Core Principles
* It's all behaviour
* Deliver stakeholder value
* Enough is enough
“ Do not overengineer, do not overdo
upfront planning, analysis and design.
Do just enough to get things started in the
right direction”
20

21. BDD's Core Principles
* It's all behaviour
* Deliver stakeholder value
* Enough is enough
“ When i wanna go to sentosa from my AMK
home, i just goto gothere.sg to do a quick
check, and that's good enough, i don't need
to get down to switching lanes on CTE,
blah blah. ” 21

22. Cucumber ? Nice to Eat ?!
22

23. Cucumber ? Nice to Eat ?!
* a tool for functional testing
23

24. Cucumber ? Nice to Eat ?!
* a tool for functional testing
* by Aslak HellesØy, & many other
nice people
24

25. Cucumber ? Nice to Eat ?!
* a tool for functional testing
* by Aslak HellesØy, & many other
nice people
* allows non-technies to express
app's functions in plain text
25

26. Cucumber ? Nice to Eat ?!
* a tool for functional testing
* by Aslak HellesØy, & many other
nice people
* allows non-technies to express
app's functions in plain text
* plain text serves as documentation
& executable examples
26

27. Hmm .. Plain Text ?!
27

28. A Prettier Plain Text
28

29. The Title
29

30. The Narrative
30

31. Guideline for the Narrative
31

32. Guideline for the Narrative
* identify the stakeholder
“ Eg. The system administrator”
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33. Guideline for the Narrative
* identify the stakeholder
* describe the feature he wants
“ Eg. Trashing of all invalid purchase
orders in the system”
33

34. Guideline for the Narrative
* identify the stakeholder
* describe the feature he wants
* the reason for wanting it
“ Eg. Prevent data corruption”
34

35. The Acceptance Criterion
35

36. The Scenario's Title
36

37. The Scenario's Steps
37

38. Given | When | Then
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39. Given | When | Then
* GIVEN ... setting up system to a
known state
“ Eg 1. Database setup ...
Given the following users already exists”
“ Eg 2. Visiting a Url ...
Given I am on users management page”
“ Eg 3. Ensure User's Login ...
Given I already login as “HappyMan””
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40. Given | When | Then
* GIVEN ... setting up system to a
known state
* WHEN ... exercising an event
“ Eg. Pressing Button ...
When I press “Help Me””
40

41. Given | When | Then
* GIVEN ... setting up system to a
known state
* WHEN ... exercising an event
* THEN ... verifying an outcome
“ Eg. Seeing a message ...
Then I should see “Login Successful””
41

42. Save & Execute It !!
* Save at:
<PROJECT_ROOT>
`~ features/
`- sign_up.feature
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43. Save & Execute It !!
* Save at:
<PROJECT_ROOT>
`~ features/
`- sign_up.feature
* Run with:
#$ cucumber features
43

44. P1
P2
44

45. 45

46. 46

47. 47

48. 48

49. 49

50. 50

51. 51

52. Step Definitions
52

53. Save & Execute It !!
* Save as:
<PROJECT_ROOT>
`~ features/
`- steps.rb
53

54. Save & Execute It !!
* Save as:
<PROJECT_ROOT>
`~ features/
`- steps.rb
* Run with:
#$ cucumber features
54

55. 55

56. 56

57. 57

58. The Functional Test Model
58

59. The Generic Model
Cucumber
* cucumber exec
* features/*.feature
* features/*.rb
59

60. The Generic Model
Cucumber
* cucumber exec Target App
* features/*.feature
* features/*.rb
60

61. The Generic Model
Cucumber
* cucumber exec Target App
* features/*.feature
* features/*.rb
Driver
61

62. The Generic Webapp Model
Cucumber
* cucumber exec
* features/*.feature
* features/*.rb
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63. The Generic Webapp Model
Cucumber Webapp
* cucumber exec * web server
* features/*.feature * deployed app
* features/*.rb * web browser
63

64. The Generic Webapp Model
Cucumber Webapp
* cucumber exec * web server
* features/*.feature * deployed files
* features/*.rb * web browser
Driver
* selenium (server+client)
64

65. FAST FOWARD
(Completed: Step Definitions)
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66. Before
After
66

67. Before
After
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68. Before
After
68

69. Before
After
69

70. Before
After
70

71. A New *.rb File
<PROJECT_ROOT>
`~ features/
`- selenium.rb
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72. 72

73. 73

74. 74

75. 75

76. 76

77. OK, Let's Run It !!
#$ cucumber features
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78. 78

79. 79

80. Run Selenium Server
#$ selenium
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81. Run Selenium Server
#$ selenium
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82. 82

83. Let's Try Again
#$ cucumber features
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84. 84

85. 85

86. The Missing Part ??
~ Our Application ~
86

87. FAST FOWARD AGAIN
(Completed: Application)
87

88. Let's Run the Webapp
#$ ruby app.rb
88

89. Let's Run the Webapp
#$ ruby app.rb
89

90. 90

91. Let's Try Once Again
#$ cucumber features
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92. Let's Try Once Again
#$ cucumber features
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93. Revision Time
93

94. Summing Up
1) Capturing user's requirements
in a feature file
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95. Feature's Title
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96. Feature's Narrative
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97. Feature's Narrative
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98. Feature's Narrative
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99. Feature's Narrative
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100. Feature's Acceptance Criterion
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101. Feature's Acceptance Criterion
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102. Feature's Acceptance Criterion
102

103. Summing Up
1) Capturing user's requirements
in a feature file
2) Complete the missing step
defintions
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104. Step Definitions
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105. Summing Up
1) Capturing user's requirements
in a feature file
2) Complete the missing step
defintions
3) Implement the application
105

106. Useful Links
* Cucumber's Wiki
http://wiki.github.com/aslakhellesoy/cucumber
* Cucumber's Homepage
http://cukes.info/
* BDD @ Wikipedia
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107. Recommended Video
107

108. THE END
108