Behavior-driven development (BDD) focuses on testing software behavior and functionality through scenarios rather than just testing units of code. BDD uses a domain-specific language like Gherkin to describe scenarios in terms of given, when, and then statements to define preconditions, events, and expected outcomes. These scenarios act as acceptance criteria that are extracted from user stories and can be executed by a tool to automatically test that the program behaves as intended.

1. Fabian Kiss
THE CONCEPT OF
BEHAVIOR-DRIVEN DEVELOPMENT

2. Unit
Testing

3. test-first
Unit
Testing

4. test-first
Unit
Testing
TDD

5. BDD
test-first
Unit
Testing
TDD

6. BDD
?
“TDD done right”

7. BDD IS NOT ABOUT TOOLS
(ALTHOUGH THERE ARE TOOLS FOR BDD)

8. BDD
actices
pr

9. BDD
actices
pr
maybe you already practice it
(without being aware of it)

10. BDD
actices
pr
maybe you already practice it
(without being aware of it)

11. BDD
actices
pr
awaren
ess

12. SYNTACTIC CONVENTIONS
method names are complete sentences
public class CustomerLookupTest extends TestCase {
testFindsCustomerById() {
...
}
testFailsForDuplicateCustomers() {
...
}
...
}
“should” instead of “test”
testShouldFailForMissingSurname
testShouldFailForMissingTitle
...
http://dannorth.net/introducing-bdd/

13. WHAT TO TEST?

14. WHAT TO TEST? UNITS

15. CODE COVERAGE ...
Picture by PeterJBellis, licensed under the CC BY 2.0

16. … A FALSE SENSE
OF SECURITY
Picture by Salim Virji, licensed under the CC BY-SA 2.0

17. WHAT TO TEST? UNITS
WHAT TO TEST?

18. WHAT TO TEST? UNITS
WHAT TO TEST? BEHAVIOR

19. BEHAVIOR
constituted by scenarios (descriptions of them)

20. BEHAVIOR
constituted by scenarios (descriptions of them)
acceptance criteria
extract
User story
As a ...
I want …
So that ...

21. BEHAVIOR
constituted by scenarios (descriptions of them)
describe in DSL → executable
acceptance criteria
extract
User story
As a ...
I want …
So that ...

22. BEHAVIOR
constituted by scenarios (descriptions of them)
describe in DSL → executable
acceptance criteria
extract Gherkin:
Given a precondition
User story When an event occurred
Then an outcome is achieved
As a ...
I want …
So that ...

23. BEHAVIOR
constituted by scenarios (descriptions of them)
describe in DSL → executable
acceptance criteria
extract Gherkin:
Given a precondition
User story When an event occurred
Then an outcome is achieved
As a ...
I want …
So that ... execute
tool