What is BDD and why should I care?

There's a lot of hype around about BDD. Here Matt talks through the basic philosophy behind BDD, how it relates to existing agile practices, and what impact it can have on your team.

Transcript

1. What is BDD ...and why should I care? @mattwynne BCS, Edinburgh 3rd October 2012
2. Living documentation BDD Kickstart.com mattwynne.net Coaching / blogging training Collaborating
3. BDD: Dual Audience Stakeholders, Customers, Users Programmers, Testers
4. Problem domain Solution domain
5. "Behaviour-Driven Development (BDD) builds upon Test-Driven Development (TDD) by formalising the good habits of the best TDD practitioners." -- The Cucumber Book, 2011
6. The best TDD practitioners... • Work from the outside-in • Use examples to clarify their requirements • Develop and use a ubiquitous language
8. UBIQUITOUS LANGUAGE
10. DDD + NLP
11. Language matters DDD + NLP
12. OUTSIDE IN
13. Outside-in
14. Why?
15. Why? Why? Why? Why? Why?
16. Organisation Goal
17. Product Features / Epics
18. User / Stakeholder Stories
19. VISA subscriptions In order to increase subscriptions visitors should be able to subscribe online with a VISA card User / Stakeholder Story
20. VISA subscriptions In order to increase subscriptions visitors should be able to subscribe online with a VISA card User / Stakeholder Story
21. VISA subscriptions In order to increase subscriptions visitors should be able to subscribe online with a VISA card User / Stakeholder Story
22. VISA subscriptions In order to increase subscriptions visitors should be able to subscribe online with a VISA card User / Stakeholder Story
23. VISA subscriptions In order to increase subscriptions visitors should be able to subscribe online with a VISA card Acceptance Criteria
24. Acceptance Criteria •Must support VISA •Does not need to support MasterCard, Switch •... •Customers should be prevented from entering invalid credit card details • ... Credit Card Processing Acceptance criteria:
25. Acceptance Criteria
26. Are we ready yet?
27. Really? So tell me... "Customers should be prevented from entering invalid credit card details"
28. Really? So tell me... "Customers should be prevented from entering invalid credit card details" • What exactly makes someone's credit card details invalid?
29. Really? So tell me... "Customers should be prevented from entering invalid credit card details" • What exactly makes someone's credit card details invalid? • Can they use spaces?
30. Really? So tell me... "Customers should be prevented from entering invalid credit card details" • What exactly makes someone's credit card details invalid? • Can they use spaces? • Should we checksum the digits?
31. Really? So tell me... "Customers should be prevented from entering invalid credit card details" • What exactly makes someone's credit card details invalid? • Can they use spaces? • Should we checksum the digits? • How do we feed back that the details are invalid?
32. Really? So tell me... "Customers should be prevented from entering invalid credit card details" • What exactly makes someone's credit card details invalid? • Can they use spaces? • Should we checksum the digits? • How do we feed back that the details are invalid?
33. Really? So tell me... "Customers should be prevented from entering invalid credit card details" • What exactly makes someone's credit card details invalid? • Can they use spaces? • Should we checksum the digits? • How do we feed back that the details are invalid? An example would be handy right about now...
34. EXAMPLES
35. Acceptance Criteria
36. Scenarios
37. "Customers should be prevented from entering invalid credit card details" 1. Customer enters a credit card number that contains only 15 digits 2. Customer tries to submit the form 3. form is re-displayed with an error message advising Customer that the correct number of digits is 16 For example, imagine this scenario:
38. "Customers should be prevented from entering invalid credit card details" 1. Customer enters a credit card number that contains only 15 digits 2. Customer tries to submit the form 3. form is re-displayed with an error message advising Customer that the correct number of digits is 16 For example, imagine this scenario: Really? Always?
39. "Customers should be prevented from entering invalid credit card details" 1. Customer enters a credit card number that contains only 15 digits 2. Customer tries to submit the form 3. form is re-displayed with an error message advising Customer that the correct number of digits is 16 For example, imagine this scenario: What if...? Really? Always?
40. Common understanding of Done
41. User Story Acceptance Criteria Scenarios
42. Scenarios
43. AUTOMATION
44. Behaviour = Context + Action + Outcome
45. Behaviour = Context + Action + Outcome Given
46. Behaviour = Context + Action + Outcome Given When
47. Behaviour = Context + Action + Outcome Given When Then
48. Scenario: Tickle a happy person Given I am in a good mood When you tickle me Then I will giggle
49. Scenario: Tickle a happy person Given I am in a good mood When you tickle me Then I will giggle
50. Scenario: Tickle a grumpy person Given I am in a bad mood When you tickle me Then I will giggle
51. Scenario: Tickle a grumpy person Given I am in a bad mood When you tickle me Then I will giggle expected: "tee hee hee", got: "bugger off"
52. Scenario: Tickle a grumpy person Given I am in a bad mood When you tickle me Then I will get cross
53. Scenario: Attack a happy person Given I am in a good mood When you kick me in the shins Then I will get cross
54. Scenario: Attack a happy person Given I am in a good mood When you kick me in the shins Then I will get cross
55. Behaviour = Context + Action + Outcome
56. Behaviour = Context + Action + Outcome Given
57. Behaviour = Context + Action + Outcome Given When
58. Behaviour = Context + Action + Outcome Given When Then
59. System = ∑(Behaviour)
60. http://cukes.info/
61. Javascript
62. Demo
63. Gherkin (language)
64. # language: en Feature: Division In order to avoid silly mistakes Cashiers must be able to calculate a fraction Scenario: Regular numbers Given I have entered 3 into the calculator And I have entered 2 into the calculator When I press divide Then the result should be 1.5 on the screen
65. # language: ja ϑΟʔνϟ: আࢉ όΧͳؒҧ͍Λආ͚ΔͨΊʹ ༗ཧ਺΋ܭࢉͰ͖Δ͜ͱ γφϦΦ: ;ͭ͏ͷ਺஋ લఏ 3 Λೖྗ ͔ͭ 2 Λೖྗ ΋͠ divide Λԡͨ͠ ͳΒ͹ 1.5 Λදࣔ
66. български català Cymraeg Česky dansk Deutsch English Australian LOLCAT Texan español eesti keel ೔ຊޠ 한국어 lietuvių kalba latviešu Nederlands norsk polski português română suomi français hrvatski magyar Bahasa Indonesia italiano русский Svenska Slovensky Узбекча Tiếng Việt 简ମதจ ൟᱪதจ תירבע !"#$%&ا
67. OH HAI: STUFFING MISHUN: CUCUMBR I CAN HAZ IN TEH BEGINNIN "3" CUCUMBRZ WEN I EAT "2" CUCUMBRZ DEN I HAZ "2" CUCUMBERZ IN MAH BELLY AN IN TEH END "1" CUCUMBRZ KTHXBAI!
68. Gherkin Fundamentals Feature: Feature name Description of feature goes here Scenario: Scenario name Description of scenario goes here Given a certain context When something happens Then an outcome And something else But not this though Scenario: Another scenario name Description of another scenario goes here ...
69. FORGET THE TOOLS
70. "Let's make toast the American way: You burn it, and I'll scrape it" - W. E. Demming
72. Plan
73. Plan Develop
74. Plan Develop Misery
75. Plan Develop Testing
76. Plan Develop Testing
77. Plan Develop Test
78. So... why should I care?
79. If you're a developer
80. If you're a developer • BDD will help you to focus
81. If you're a developer • BDD will help you to focus • BDD will give you confidence to refactor
82. If you're a developer • BDD will help you to focus • BDD will give you confidence to refactor • BDD will help you to understand the business-facing people on your team better
83. If you're a product owner or business analyst
84. If you're a product owner or business analyst • BDD will give you a greater insight into the complexity of what you're asking for
85. If you're a product owner or business analyst • BDD will give you a greater insight into the complexity of what you're asking for • BDD will give you transparency about what the team are doing in each iteration
86. If you're a product owner or business analyst • BDD will give you a greater insight into the complexity of what you're asking for • BDD will give you transparency about what the team are doing in each iteration • BDD will help your team ship faster
87. If you're a tester
88. If you're a tester • BDD will mean you can find bugs before they've even been written
89. If you're a tester • BDD will mean you can find bugs before they've even been written • BDD will free you to do interesting, creative, exploratory testing
90. If you're a project manager
91. If you're a project manager • BDD will help your team achieve a steadier, more predictable, and ultimately faster pace
92. Thanks • matt@mattwynne.net • @mattwynne • http://blog.mattwynne.net