The Behaviour-Driven Programmer

An introduction to Behaviour-Driven Development, the second-generation agile methodology that aims at delivering software that matters.

Most of us know that BDD has something to do with tests and the way code is produced. But what is it exactly? How does it differ from Test-Driven Development?

We’ll discover the technical principles and practices lying at the heart of BDD, as experienced from a naive programmer perspective.

But BDD is not only about writing better tests and code. It really holds higher purposes...

Transcript

1. !" B"#$v%&'r-Dr%v"( Pr&)r$**"r The first steps of a Behaviour-Driven Developer v0.1-alpha
2. Julien Biezemans @jbpros
3. Who?
4. You happen to write code...
5. useless,
6. delivered (too) late,
7. fragile,
8. difficult to deploy,
9. impenetrable,
10. hard to maintain.
11. BDD
12. Dan North @tastapod
13. “BDD is a second-generation, outside- in, pull-based, multiple-stakeholder, multiple-scale, high-automation, agile methodology.”
14. “It describes a cycle of interactions with well-defined outputs, resulting in the delivery of working, tested software that matters.”
15. Test-Driven Development
16. Red, Green, Refactor
17. Where to start?
18. What to test?
19. Behaviour
21. From Test to Behaviour
22. Most important missing behaviour today?
23. Business value
24. Story
25. As ... I want ... So that ...
26. Estimation
27. Acceptance criteria
28. Scenario
29. Context ➔ Event ➔ Outcome
30. Given ➔ When ➔ Then
31. Ubiquitous Language
32. BDD in Ruby/Rails
33. Stories + Scenarios = Cucumber features
34. Cucumber http://github.com/cucumber
35. Full-stack, deliverable
36. Outside-in
37. Acceptance tests Unit tests Code
40. Run feature
42. Missing step definition #fail
43. Write step definition
44. features/step_definitions/tamagotchi_steps.rb
45. bin/app.rb
46. Run feature
48. Missing code #fail
49. RSpec http://github.com/rspec
50. Write spec
51. spec/lib/tamagotchi_spec.rb
52. Run spec
54. Missing code #fail
55. Make it pass
56. lib/tamagotchi.rb
58. Refactor
59. Repeat until the feature passes
61. Design
62. spec/lib/tamagotchi_spec.rb
63. spec/lib/tamagotchi_spec.rb
65. lib/tamagotchi.rb
67. lib/tamagotchi.rb
69. spec/lib/tamagotchi_spec.rb
71. Stubs
72. spec/lib/tamagotchi_spec.rb
74. lib/tamagotchi.rb
76. spec/lib/tamagotchi_spec.rb
77. spec/lib/tamagotchi_spec.rb
80. Spec everything your step definitions need
81. spec/lib/tamagotchi_spec.rb
82. lib/tamagotchi.rb
85. spec/lib/tamagotchi_spec.rb
86. lib/tamagotchi.rb
89. features/step_definitions/tamagotchi_steps.rb
94. Living documentation
95. Ruby on Rails
96. View ➔ Controller ➔ Model
97. From Programmer to Developer
98. To provide (a machine) with a set of coded working instructions. program v.
99. develop v. To bring out the capabilities of; bring to a more advanced or effective state.
100. Deliberate discovery
101. Know what you don’t know
102. Know what you don’t know you don’t know
103. Learn the domains
104. Learn the tools
105. Know the people
106. Feedback
107. Real options
108. Practice
109. Your code is now...
110. useful,
111. delivered on time,
112. robust,
113. easily deployable,
114. intelligible,
115. maintainable,
116. A piece of software that matters.
117. Don’t deliver features
118. Ship capabilities!