This document discusses Behavior Driven Development (BDD) using Cucumber for Java. It explains that BDD combines test-driven development, domain-driven design, and other good practices to develop software using a common language that is readable to both business and technical stakeholders. Cucumber allows writing automated tests in a format of Given-When-Then scenarios that can be parsed and executed to verify the system behaves as specified. The document provides an example scenario written in the Cucumber format and demonstrates how to write Java code to implement the steps and make the test pass.

1. Behaviour Driven Development
with Cucumber for Java

2. BDD
Domain Driven Design - DDD
● Common understanding
● Common language
● Test Driven Development - TDD
● Good technical practices
● Small steps
● Combined → Behaviour Driven Development

3. Test automation
 Test Driven Development, TDD – Develop it the
right way
 Behaviour Driven Development, BDD –
Develop the right thing

4. Three core principles
• Business and Technology should refer to the same system in
the same way
• Any system should have an identified, verifiable value
• Up-front analysis, design and planning all have a diminishing
return

5. Common language
Used by all involved
• Customer
• Developers
• Others?

6. Verifiable value
• Protect revenue
• Increase revenue
• Manage cost
• Increase brand value
• Make the product remarkable
• Provide more value to your customer

7. Big design up-front
• No big design up-front
• The further you plan ahead, the less accurate you will be

8. Three questions
• What is the most important thing the system should do?
• What is the next most important thing the system doesn't do
yet?
• If we were to switch off the system, where and what would be
the biggest impact?

9. Time to create a specification

10. Time to create a specification
When are we done?

11. Interpret and translate
 We need to read the spec.
 Understand it
 Translate it into code
 Parse and execute it?
 No, not all specs are created equal

12. Solution
Write specifications so
 Translations isn't needed
 It is possible to execute them

13. Format
• Given – Setup the system
• When – Change the state of the system
• Then – Verify the new state

14. Tools

15. Audience
Readers
 Customers
 Developers
Maintainers
 Product owner
 Developers

16. Why Cucumber
 It is one of the least technical tools
 It is a very active open source project
 It supports a variety of languages

17. A concrete example
Feature: Life of IT guys
In order to get good salary
As a it guy
I want to keep my boss happy
Scenario: I am a tester
Given I am a bad tester
When I go to work
Then I mess with it
And my boss fires me
But the developer likes me

18. Advantages
The format is
● Easy to read
● Easy to understand
● Easy to discuss
● Easy to parse

19. Parse and execute
● A parser is developed
● Add native code to implement the steps
 Setup – Given
 Execute – When
 Assert - Then

20. Write a step definition in Java
@Given("^I am a bad tester$")
public void I_am_a_bad_tester(){
System.out.println("@Given--I am a bad tester");
}
@When("^I go to work$")
public void I_go_to_work(){
System.out.println("@When---I go o work");
}
@Then("^I mess it$")
public void I_mess_with_it(){
System.out.println("@Then--I mess it");
}
@And("^my boss fires me$")
public void my_boss_fires_me(){
System.out.println("@And---my boss fires me");
}
@But("^the developer likes me$")
public void the_developer_likes_me(){
System.out.println("@But--the developer likes me");
Assert.assertTrue(false);
}

21. Run it and watch it fail

22. Write code to make the step pass
@Given("^I am a [a-zA-Z]{1,} tester$")
public void I_am_a_bad_tester(){
System.out.println("@Given--I am a bad tester");
}
@When("^I go to work$")
public void I_go_to_work(){
System.out.println("@When---I go o work");
}
@Then("^I [a-zA-Z]{1,} it$")
public void I_mess_with_it(){
System.out.println("@Then--I mess it");
}
@And("^my boss [a-zA-Z]{1,} me$")
public void my_boss_fires_me(){
System.out.println("@And---my boss fires me");
}
@But("^the developer [a-zA-Z]{1,} me$")
public void the_developer_likes_me(){
System.out.println("@But--the developer likes me");
}

23. Run it again and see the step
pass

24. Why is Cucumber better
● Compared to well known tools like JUnit?
● It isn't, it's just easier to read for non coders
● The readability has increased
● Communication is easier

25. Benefits
● Less unnecessary work
● Better regression tests
● Less speculative work
● Less re-work

26. Maintenance
 Maintained together
● Specs
● Tests
● Code
 Maven
 Continuous Integration, CI

27. Tips
 Always use the a common language
 Don't over specify – start easy
 Never specify implementation details

28. Do not focus on tools
• They will never solve the problem
• A fool with a tool is still a fool

29. Resources
 Cucumber - http://cukes.info/
 Selenium - http://seleniumhq.org/
 Maven - http://maven.apache.org/
 Jenkins - http://jenkins-ci.org/
 Blog -http://thomassundberg.wordpress.com/

30. Thank You