BDD, from feature to unit testing

More and more software developers and companies are looking to adopt testing as a way to improve the quality and stability of written code.

Behavior-driven development (BDD) is a technique that was created to try to improve communication between business/product and engineering, enabling business/product to better contribute to software specification so that engineering can use these specifications to write code.

When applied to automated testing, BDD offers some "best practices" for writing great tests.

BDD can, and should, be used in conjunction with Test Driven Development and Unit Testing techniques, as it offers detailed specifications that will be extremely useful in the test writing process.

Transcript

1. BDD, from feature to unit testing Henrique Valcanaia
2. BDD, from feature to unit testing Henrique Valcanaia
3. Henrique Valcanaia
4. programming since '09
5. ~10y writing "hacks"
6. Computer Engineering @ UFRGS
7. Apple Developer Academy 2015/2016
8. iOS ~5 years ⌚
10. https://bit.ly/projetobdd
12. how this talk was born?
13. what's the goal with this talk
14. awesome experience to end user
15. robust applications
16. define: robustness
17. ability to withstand or overcome adverse conditions or rigorous testing
18. how did I start seeking robustness?
19. ~la garantia soy yo~
20. I DON'T MAKE MISTAKES
21. next professional step? ❓
22. tests, of course ❗
23. let's see how test works
25. I don't do TDD ❌
26. I don't always do TDD
27. things that change constantly
28. business rules
29. critical systems ⏱
30. critical and real time systems???
31. define: critical system
32. "a system which must be highly reliable and retain this reliability as they evolve without incurring prohibitive costs" 2010 17th IEEE International Conference and Workshops on Engineering of Computer-Based Systems Evolving Critical Systems: a Research Agenda for Computer-Based Systems Mike Hinchey and Lorcan Coyle Lero—the Irish Software Engineering Research Centre University of Limerick, Ireland Email: mike.hinchey@lero.ie, lorcan.coyle@lero.ie https://ulir.ul.ie/bitstream/handle/10344/2085/2010_Hinchey,M.pdf?sequence=2
33. "increasingly software can be considered to be critical, due to the business or other functionality which it supports" 2010 17th IEEE International Conference and Workshops on Engineering of Computer-Based Systems Evolving Critical Systems: a Research Agenda for Computer-Based Systems Mike Hinchey and Lorcan Coyle Lero—the Irish Software Engineering Research Centre University of Limerick, Ireland Email: mike.hinchey@lero.ie, lorcan.coyle@lero.ie https://ulir.ul.ie/bitstream/handle/10344/2085/2010_Hinchey,M.pdf?sequence=2
34. "upgrades or changes to such software are expensive and risky, primarily because the software has not been designed and built for ease of change" 2010 17th IEEE International Conference and Workshops on Engineering of Computer-Based Systems Evolving Critical Systems: a Research Agenda for Computer-Based Systems Mike Hinchey and Lorcan Coyle Lero—the Irish Software Engineering Research Centre University of Limerick, Ireland Email: mike.hinchey@lero.ie, lorcan.coyle@lero.ie https://ulir.ul.ie/bitstream/handle/10344/2085/2010_Hinchey,M.pdf?sequence=2
35. "expertise, tools and methodologies which support the design and implementation of software systems that evolve without risk (of failure or loss of quality) are essential" 2010 17th IEEE International Conference and Workshops on Engineering of Computer-Based Systems Evolving Critical Systems: a Research Agenda for Computer-Based Systems Mike Hinchey and Lorcan Coyle Lero—the Irish Software Engineering Research Centre University of Limerick, Ireland Email: mike.hinchey@lero.ie, lorcan.coyle@lero.ie https://ulir.ul.ie/bitstream/handle/10344/2085/2010_Hinchey,M.pdf?sequence=2
36. Boeing 737 MAX
37. and?
38. Lion Air 737 MAX crash in Indonesia
39. First report Oct 25, 2019 Page 216
40. First report Oct 25, 2019 Page 216
41. who's guilty?
42. does this question even make sense?
43. future society about software?
44. why are we talking about this?! ¯\_(ツ)_/¯
45. To achieve Robustness
46. Behaviour-driven development
47. Behaviour Driven Development
48. Test-Driven Development++ Acceptance Test-Driven Planning++ https://web.archive.org/ web/20150901151029/ http://behaviourdriven.org/
49. but what is BDD?
50. BDD is not a silver bullet
51. an Agile software development process that encourages collaboration among developers, QA and non-technical or business participants in a software project https://en.wikipedia.org/wiki/ Behavior-driven_development
52. improve communication between tech and non tech people
53. prevent wrong assumptions
54. Introducing BDD. Daniel Terhorst-North. Better Software, March 2006. https://dannorth.net/introducing-bdd/
55. Dan was very happy doing Agile, TDD, etc.
56. same confusion and misunderstandings
57. extreme TDD
58. DEV: Where do I start?
59. DEV: What should I test?
60. DEV: How much to test at the moment?
61. do you see where we're heading to?
62. perfect testable beautiful code, of course
63. "if someone had told me that!"
64. improve communication between tech and non tech people
65. prevent wrong assumptions
66. makes sense?!
67. BDD to the rescue
68. Software = User Story + Acceptance Criteria
69. similar to Domain-Driven Development
70. As a [person who will benefit], I want [some feature], so that [the benefit or value of the feature].
71. Given [some initial context], when [an event occurs], then [ensure some outcomes].
72. checkpoint ✅
73. user stories acceptance criterias tests code
74. shut up and talk about iOS
75. BDD frameworks in Swift
77. Quick (8.5k⭐) https://github.com/ Quick/Quick a behavior-driven development framework for Swift and Objective-C. Inspired by RSpec, Specta, and Ginkgo
78. Nimble (3.5k⭐) https://github.com/ Quick/Nimble express the expected outcomes of Swift or Objective-C expressions. Inspired by Cedar
79. it("") { } defines an example
80. describe("") { } context("") { } defines a logical groupings of examples
82. As a user I want to see a list of Marvel's comics So that I can learn more about it
83. Given that the app has internet connection When the app opens Then show the comics list
85. BDD is about integration tests ♻
86. "an application behavior can be described by the integration of its components behaviors"
87. To achieve Robustness
88. increase agility on Xcode
90. default iOS target
91. unit testing
94. Given_that_I_have_internet_connenction__ When_the_server_response_is_inlivad__ Then_present_an_error_message_informing_ that_the_content_couldn_t_be_read()
95. Given_that_I_have_internet_connenction__ When_the_server_response_is_inlivad__ Then_present_an_error_message_informing_ that_the_content_couldn_t_be_read()
96. macOS unit test
99. UI tests
110. we're testing integration between modules ♻
111. what about unit testing?
112. when do I get to choose my architecture
113. when you have all the specs
114. behaviours
115. user stories
116. acceptance criterias ✅
117. https://iosarchitecture.top/
118. now TDD, right?
119. use BDD to define your components behavior
120. helps you define components responbabilities ⚙
121. decoupled and specific targets
122. go with behavior until you have a unit ☝
123. now you do TDD!
124. checkpoint ✅
125. describe behavior until you have a unit
126. extra
127. launch arguments
129. issues
130. • Insufficient budget • Size of the team • Poor outside feedback • Minimum business logic • Too many meetings • Bad planning and unrealistic expectations • Inadequate communication • Treating quality as solely the testers’ responsibility • Inconsistent formatting for BDD scenarios
131. recap
132. • BDD is about the process • BDD is not a silver bullet • BDD helps specify the product • BDD can help in business validation and clarification • Integration tests can be felt as an overhead, but are essencial to scalable/critical applications • Tests outputs are easier to understand • Low coupling • Communication++
133. https://bit.ly/projetobdd
134. https://iosdevbr.herokuapp.com/
135. that's all folks
136. thanks!
137. @ricovalcanaia @hvsw Henrique Valcanaia @valcanaia