BDD in Action discusses how the author has implemented Behavior Driven Development (BDD) in their projects. BDD uses examples to describe software behaviors and tests scenarios first before development. The author explains how using Gherkin language and Cucumber automation tools allowed them to write acceptance criteria as examples, collaborate with business stakeholders, and develop using a test-first approach. Challenges included experimental scenario writing and appium instability, but overall BDD provided living documentation, less regression testing, and ensured development matched stakeholder expectations.

1. BDD in Action
HOW WE HAVE DONE IT IN OUR PROJECTS

2. About me
• Nguyen Xuan Kien
• Developer since 2006
• CurrentlyTechnical Leader at Shippo.vn
• Interested in Software Architecture
• Developing & managing 2 projects with BDD

3. BDD in action – how we have done it
• Why we choose BDD
• What is BDD
• BDD in Action

4. Why we use BDD

5. Bug cost

6. Bug cost in one of my previous project
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Nov-15 Dec-15 Jan-16 Feb-16 Mar-16
Fixing bug time ratio in Seudo.vn
Bugs New features Others

7. After TDD applied
• Bugs reduced
• No serious hidden bug
• The user flow is still not as P.O expected
• P.O wasted time on write detailed feature specification
• Team members understand feature differently

8. More reasons
• Still not safe because of hidden “wrong feature”
• Manual regression test become bigger and bigger
• AcceptanceTest Automation needed
• Lack of documentation make training longer
• More different understanding betweenTester and Dev

9. What is BDD?
• Behavior Driven Development
• TDD (Test-driven-development)
• DDD (Domain-driven-design)

10. TDD
• Test-driven development
• A short development cycle
• Write a test first, write function after
• It’s not about test first, but about thinking first
• Make program do exactly as programmer want

11. DDD
• Domain-driven development
• Domain experts and Dev team understand the same
• Decoupling with domain
• And many pros in Software Architecture

12. BDD
• Use the ubiquitous language for both Business interests andTechnical
interest
• Write scenarios first (software behaviors)
• Scenarios could be use as living document
• Scenarios could be use asTesting Automation scripts
• Could be understand asTDD with AcceptanceTest, orAcceptance-
Test driven development with DDD in mind

13. BDD in Action
• Gherkin as test script language
• Cucumber for JVM as AutomationTools
• Selenium for Browser Automation, Appium for Mobile Apps
Automation
• Specification with examples

14. Gherkin
• Its meaning is one type of pickled cucumber
• A language for both Developer and Business
• Features, Scenarios and Steps

15. Example of Gherkin

16. Cucumber for JVM
• Execute Gherkin language as test script
• Could be in any layer
• View (use Selenium as Browser Driver)
• API (use your own custom API Client)
• Unit-test
• PerformanceTest
• There is alternative to Cucumber

17. BDD in Action workflow
• Business requirements from the domain experts
• Write specifications as Example
• Examples become living document
• Have test scripts as a by product
• Software development in a test-first approach

18. What is important to our Product?

19. Write Acceptance Criteria
• As a potential customer I want to collect products to shopping cart so
that I can order many products at once
How can I verify
that this story has
been fulfilled?
I would want to add a product
I would want to remove product
I would want to check how many
product I’ve added
I may add the same product
again to the cart

20. We need examples to these AC
Example Tests
Requirements
Consists of
Verify the fulfillmentDescribe

21. Further discussion of the AC
When I add to the
same product, its
quantity should be
increased
Add 3 “BDD in action” to cart
Open “BDD in action” detail
Input 2 in quantity input
Click “Add to cart”
Verify quantity in cart is 5
public voidTestAddToCart() {
….
}

22. Further discussion of the AC
What if I add too
many products?
No, the maximum
just need to equal to
our stock
But we warning him that
his money is not enough,
it would be wonderfulBut that would be
impossible for us to do it!
Again, we should care
about the performance if
too many products…

23. Collaboration of the 3 amigos
• Happy case
• Technical Possibility
• Exceptions, border cases
• Discover hidden assumptions between 3 of them

24. After an discussion we have an example
• Scenario: I should be able to add the same product to my cart
• Given I have 3 “BDD in action book” in my cart
• When I add 2 “BDD in action book” to my cart
• Then I should have 5 “BDD in action book” in my cart

25. A Scenario should be
• Use as “living” document for both Dev team and Business
• Use as AcceptanceTesting Automation Script
• Not trying to automate manual test
• Not trying to easy to automate but unreadable
• Not written after completing development

26. A Scenario format
• Title should describes what we want
• Given: the condition that we could be in this scenario
• When: what will trigger this scenario
• Then: the outcome we want

27. Workflow after that

28. Feature

29. Step defines

30. Writing step defines to automate test
• Context is important in each scenario
• Each scenario should be independence
• Steps should be reusable
• Each step is unique, understandable in only one way

31. Finally
• We could have user story done as customer really want
• Some User Story could break after completing others, but we could
handle it with less manual regression test
• We have the document for both Development and Business
• We face many challenges on the way, but we believe in the future

32. Our challenges
• Experimental ScenarioWriting
• Lack of documentation and Examples
• Limited suggestion from community
• Appium is not very stable yet (at least for React Native and iOS)

33. Gherkin Automation tools

34. Automation drivers
• Selenium for Browsers
• Appium forApplication Driver
• Unit-testing for internal logic layers

35. Do you want practice?

36. Questions and Answers
WITH SHOWCASES

37. THANKS FORYOUR ATTENTION
For further discussion contact me at:
koh2203@gmail.com
nguyenxuankien@shippo.vn
https://facebook.com/kiennx