Introduction to BDD with Cucumber for Java
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This document introduces Behavior Driven Development (BDD) using Cucumber for Java, highlighting its principles, practices, and the importance of collaboration among stakeholders. It emphasizes the creation of a ubiquitous language for effective communication and illustrates the role of living documentation in defining software functionality through examples. Additionally, it discusses the significance of interactions in software development, encouraging teams to discover requirements collaboratively.
![@sebrose h)p://cucumber.io
Given/When/Then namespaces
Global namespace
-‐ Given/When/Then interchangeable
Separate namespaces
-‐ Given/When/Then disBnct
-‐ And/But bind to preceding namespace
-‐ [StepDefiniBon] for compaBbility](https://image.slidesharecdn.com/bddintrowithcucumberjava-151026202046-lva1-app6891/85/Introduction-to-BDD-with-Cucumber-for-Java-20-320.jpg)
Introduction to BDD with Cucumber for Java
- 1. Seb Rose [email protected] @sebrose h0p://cucumber.io An Introduc9on to Behaviour Driven Development with Cucumber for Java
- 2. @sebrose h)p://cucumber.io Agenda -‐ What is BDD? -‐ What is Cucumber? -‐ Demo Cucumber for Java -‐ Cucumber variants -‐ Pu@ng it all together
- 3. @sebrose h)p://cucumber.io What is BDD? Behaviour Driven DevelopmentDesign
- 4. @sebrose h)p://cucumber.io BDD is a second-‐generaBon, outside-‐in, pull-‐based, mulBple-‐stakeholder, mulBple-‐scale, high-‐automaBon, agile methodology. It describes a cycle of interacBons with well-‐defined outputs, resulBng in the delivery of working, tested soJware that ma)ers. Dan North h)p://skillsma)er.com/podcast/java-‐jee/how-‐to-‐sell-‐bdd-‐to-‐the-‐business BDD defined
- 5. @sebrose h)p://cucumber.io The power of “should” -‐Diverts developers from their distaste for tesBng -‐Encourages people to ask “Should it really?”
- 6. @sebrose h)p://cucumber.io Deliberate discovery “… during an incepBon, when we are most ignorant about most aspects of the project, the best use we can possibly make of the Bme available is to a)empt to idenBfy and reduce our ignorance …” Dan North h)p://dannorth.net/2010/08/30/introducing-‐deliberate-‐discovery/
- 7. @sebrose h)p://cucumber.io Ubiquitous language “The pracBce of building up a common, rigorous language between developers and users” MarBn Fowler
- 8. @sebrose h)p://cucumber.io The 3 Amigos The one where... User stories & acceptance criteria Examples Open quesBons Domain learning
- 9. @sebrose h)p://cucumber.io Example mapping Acceptance Criterion (Rule) User Story Example Open Question Acceptance Criterion (Rule) Acceptance Criterion (Rule) Example Example Example Example Example
- 10. @sebrose h)p://cucumber.io Important conversaBons having conversaBons is more important than capturing conversaBons is more important than automa.ng conversaBons Liz Keogh h)p://lizkeogh.com/2014/01/22/using-‐bdd-‐with-‐legacy-‐systems/
- 11. @sebrose h)p://cucumber.io Living documentaBon a.k.a Executable specificaBon Living documentaBon is a reliable and authoritaBve source of informaBon on system funcBonality, which anyone can easily access. It is as reliable as the code, but much easier to read and understand. Gojko Adzic h)p://specificaBonbyexample.com/key_ideas.html
- 12. @sebrose h)p://cucumber.io What BDD is not…. -‐ Using “Given/When/Then” -‐ The responsibility of testers -‐ An alternaBve to manual tesBng
- 13. @sebrose h)p://cucumber.io What is Cucumber? Features -Scenarios -‐Steps -Gherkin Glue code -Step definiBons -Ruby -Java -C# & others ApplicaBon
- 14. @sebrose h)p://cucumber.io Feature: Team Scoring Teams start with zero score. Correct answer gets points depending on how difficult it is. Scenario: New teams should not have scored yet Given I register a team Then my score is 0 Scenario: Correctly answering a question scores points Given I register a team When I submit a correct answer Then my score is 10
- 15. @sebrose h)p://cucumber.io Feature: Feature name Descrip8on of feature goes here Scenario: Scenario name Descrip8on 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 ... Gherkin fundamentals
- 16. @sebrose h)p://cucumber.io Given(/^I register a team$/) do # Glue code goes here end Ruby
- 17. @sebrose h)p://cucumber.io import cucumber.api.java.en.*; public class MyStepDefinitions { @Given("^I register a team$") public void iRegisterATeam() throws Throwable { // Glue code goes here } } Java
- 18. @sebrose h)p://cucumber.io
- 19. @sebrose h)p://cucumber.io Cucumber variants • Ruby • C# (Specflow) • Java (& other JVM languages) • Javascript • PHP • Python • C++
- 20. @sebrose h)p://cucumber.io Given/When/Then namespaces Global namespace -‐ Given/When/Then interchangeable Separate namespaces -‐ Given/When/Then disBnct -‐ And/But bind to preceding namespace -‐ [StepDefiniBon] for compaBbility
- 21. @sebrose h)p://cucumber.io Binding & test frameworks Behind the scenes -‐ may need to specify paths -‐ select required plugin(s) Some magic code generaBon -‐ NUnit by default -‐ configuraBon changes for others -‐ several output opBons
- 22. @sebrose h)p://cucumber.io Sharing data between steps Varies by implementaBon -‐ Ruby, Javascript: World object -‐ Java: Dependency InjecBon Context object(s) -‐ Injected -‐ Scenario -‐ Feature
- 23. @sebrose h)p://cucumber.io Hooks Before & AJer Ruby: Around, AJerStep Before & AJer BeforeStep & AJerStep BeforeFeature & AJerFeature BeforeTestRun & AJerTestRun BeforeScenarioBlock & AJerScenarioBlock
- 24. @sebrose h)p://cucumber.io Pu@ng it all together SoJware development is hard. Understanding what your methods and tools are good for can make it easier.
- 25. @sebrose h)p://cucumber.io Tools are not essenBal
- 26. @sebrose h)p://cucumber.io BDD is a second-‐generaBon, outside-‐in, pull-‐based, mulBple-‐stakeholder, mulBple-‐scale, high-‐automaBon, agile methodology. It describes a cycle of interacBons with well-‐defined outputs, resulBng in the delivery of working, tested soJware that ma)ers. Dan North h)p://skillsma)er.com/podcast/java-‐jee/how-‐to-‐sell-‐bdd-‐to-‐the-‐business BDD redefined
- 27. @sebrose h)p://cucumber.io h)ps://cucumber.pro/blog/2014/03/03/the-‐worlds-‐most-‐misunderstood-‐collaboraBon-‐tool.html When you do BDD/SpecificaBon by Example and Outside-‐in, regression tests fall out at the other end. They are a by-‐ product of those acBviBes. TesBng isn't the acBvity itself. Cucumber is first a foremost a collaboraBon tool that aims to bring a common understanding to soJware teams -‐ across roles. Aslak Hellesøy It’s about collaboraBon
- 28. @sebrose h)p://cucumber.io We sBll need testers
- 29. @sebrose h)p://cucumber.io h)p://claysnow.co.uk/architectural-‐alignment-‐and-‐test-‐induced-‐design-‐damage-‐fallacy/ Test = check + explore
- 30. @sebrose h)p://cucumber.io So much can go wrong!
- 31. @sebrose h)p://cucumber.io h)p://1.bp.blogspot.com/_YzKCMr-‐tcMM/TFLIGeqTJfI/AAAAAAAAARQ/AhNW62KX5EA/s1600/cartoon6.jpg AutomaBon is development
- 32. @sebrose h)p://cucumber.io Understand designs Features -Scenarios -‐Steps -Gherkin Glue code -Step definiBons -Ruby -Java -C# & others ApplicaBon Support code
- 33. @sebrose h)p://cucumber.io This page intenBonally blank. <role> will write scenarios
- 34. @sebrose h)p://cucumber.io More does not mean be)er
- 35. @sebrose h)p://cucumber.io “I get paid for code that works, not for tests, so my philosophy is to test as li)le as possible to reach a given level of confidence ... “I suspect this level of confidence is high compared to industry standards” h)p://stackoverflow.com/quesBons/153234/how-‐deep-‐are-‐your-‐unit-‐tests/153565#153565 Kent Beck It’s about confidence
- 36. @sebrose h)p://cucumber.io How many guy ropes?
- 37. @sebrose h)p://cucumber.io Clarity over detail
- 38. @sebrose h)p://cucumber.io ImperaBve DeclaraBve Avoid incidental details Keep it focussed
- 39. @sebrose h)p://cucumber.io TDD, ATDD, BDD, SBE …
- 40. h)p://lizkeogh.com/2011/06/27/atdd-‐vs-‐bdd-‐and-‐a-‐po)ed-‐history-‐of-‐some-‐related-‐stuff/ What’s the difference between TDD, ATDD, BDD and SbE? They’re called different things
- 41. The best TDD pracBBoners... • Work from the outside-‐in, i.e. test-‐first • Use examples to clarify their requirements • Develop and use a ubiquitous language
- 42. The best BDD pracBBoners... • Focus on value • Discover examples collabora7vely • Create living documenta7on
- 43. @sebrose h)p://cucumber.io JUnit or Cucumber?
- 44. @sebrose h)p://cucumber.io Take aways • BDD is about collaboraBon • You need a ubiquitous language • Cucumber can power conversaBon • and produce living documentaBon • but it’s no subsBtute for tesBng!
- 45. Seb Rose Twi)er: @sebrose Blog: www.claysnow.co.uk E-‐mail: [email protected] QuesBons? Discount code at pragprog.com Java_One_25%_Off_Cuke Valid for 1 month
- 46. @sebrose h)p://cucumber.io h)ps://cemarking.net/wp-‐content/uploads/2014/01/User-‐Manual_featured.jpg DocumentaBon
- 47. Acceptance criteria User Story Examples Feature: Team Scoring Teams start with zero score. Correct answer gets points depending on how difficult it is. Scenario: Score starts at 0 Given I register a team Then my score is 0 Scenario: Correct easy answer scores 10 Given I register a team When I submit a correct easy answer Then my score is 10 Scenario: Correct hard answer scores 50 Given I register a team When I submit a correct hard answer Then my score is 50
- 48. Step outcome !Passed " No exception thrown !Pending " Pending exception thrown !Undefined " No matching step definition found !Failed " Any other exception thrown !Skipped " Steps that follow a Pending, Undefined or Failed step !Duplicate " Step matches more than one step definition @sebrose http://claysnow.co.uk
- 49. Scenario outcome !Passed " All steps passed !Failed " Any step failed !Undefined " No failed steps " At least one undefined step !Pending " No failed or undefined steps " At least one pending step @sebrose http://claysnow.co.uk