Presented at GoTo Night Zurich, June 12 2014 Many teams struggle with the implementation of user story acceptance criteria and establishing a shared understanding about the expected story outcomes. This results in missed stakeholder expectations and ad-hoc assumptions made by the team. High efforts for regression testing and the lack of a reliable documentation about the current system behavior are further problems resulting from an unstructured approach to define and validate acceptance criteria. In this session, you will learn how specification-by-example addresses these problems and overall increases the level of clarity on the project end-to-end. The presentation will cover the theory and practical experience from real projects, with concrete implementation examples based on the Gherkin specification language, that can be used for automated specification validation (available for .NET, Java, Ruby, PHP, JavaScript). You will leave this session with a fundamental understanding of specification-by-example and its benefits, as well as concrete pointers on how to get started using it in your own projects.

1. FROM STAKEHOLDER EXAMPLES TO LIVING DOCUMENTATION
Specification-By-Example
with Gherkin
Christian Hassa - ch@techtalk.ch - Twitter: @chrishassa
GoTo Night Zurich, June 12th 2014

2. 2
2000 2009
2010
2007
Scrum
1997
1992 2014

3. 7
User Story life-cycle
Idea
Need
Problem

4. 8
Impact Mapping
Story Mapping
Specification-By-Example
Why?
Outcomes
Specifications
How?
Acceptance
Criteria
Epics
Deliverables
Impacts
earlier later
User Activities
User Stories
Examples
Goals
Agile Product Ownership
Code

5. 9
Evolving
User Stories
into
Specifications

6. 10
Impact Mapping
Story Mapping
Specification-By-Example
Why?
Outcomes
Specifications
How?
Acceptance
Criteria
Epics
Deliverables
Impacts
earlier later
User Activities
User Stories
Examples
Goals
Specifying user stories
Code

7. 11
Why?
Outcomes
Specifications
How?
Epics
Deliverables
Impacts
earlier later
User Activities
User Stories
Goals
Specifying user stories
Code
Reminder
for a
conversation

8. 12
Having a conversation …
Register as “bart_bookworm”
Go to “/catalog/search”
Enter “ISBN-0955683610”
Click “Search”
Click “Add to Cart”
Click “View Cart”
Verify “Subtotal” is “$33.75”
We would like to encourage new users to
buy in our shop.
Therefore we offer 10% discount for their
first order.
Original idea for the illustration: George Dinwiddie
http://blog.gdinwidiee.com
public void CalculateDiscount(Order order)
{
if (order.Customer.IsNew)
order.FinalAmount =
Math.Round(order.Total * 9/10);
}

9. 13
Specification-By-Example
Why?
Outcomes
Specifications
How?
Acceptance
Criteria
Epics
Deliverables
Impacts
earlier later
User Activities
User Stories
Examples
Goals
Establishing a shared understanding
Code
Bug
reports
Isolated,
formalized
examples

10. 14
Specification-by-Example
Examples …
• make abstract descriptions
better understandable
However …
• examples are usually not formally
exchanged or documented
Brian Marick
Examples Tests
Requirements
consist of
describe verify
fulfillment of

11. 15
Discussing acceptance criteria …
Register as “bart_bookworm”
Go to “/catalog/search”
Enter “ISBN-0955683610”
Click “Search”
Click “Add to Cart”
Click “View Cart”
Verify “Subtotal” is “$33.75”
We would like to encourage new users to
buy in our shop.
Therefore we offer 10% discount for their
first order.
Original idea for the illustration: George Dinwiddie
http://blog.gdinwidiee.com
public void CalculateDiscount(Order order)
{
if (order.Customer.IsNew)
order.FinalAmount =
Math.Round(order.Total * 9/10);
}

12. 16
… illustrated with formalized examples
Given the user has not ordered yet
When the user adds a book with the price of EUR 37.5
into the shopping cart
Then the shopping cart sub-total is EUR 33.75.
Original idea for the illustration: George Dinwiddie
http://blog.gdinwidiee.com
We would like to encourage new users to
buy in our shop.
Therefore we offer 10% discount for their
first order.

13. 17
Discover hidden assumptions
Actually, this is not quite right:
Books on sale should be excluded.
Original idea for the illustration: George Dinwiddie
http://blog.gdinwidiee.com

14. 18
Collaboration: 3 amigos
“Happy
Path”
Technical
feasability
Exceptions,
border cases
Original idea for the illustration: George Dinwiddie
http://blog.gdinwidiee.com

15. 19
Structuring
the conversation

16. 20
Collecting Acceptance Criteria
“I would try to put a book into the
shopping cart …”
“I would try to remove a book
from the shopping cart…”
“I’d check whether the shopping cart
is empty, when I enter the shop …”
Books can be added to
shopping cart.
Books can be removed from
shopping cart.
Shopping cart should be empty
when entering the shop.
... ? …
As a potential customer
I want to collect books in a shopping cart
So that I can order several books at once.
“Imagine this story is
already implemented:
How would you verify it?”
“I would try to add 1000 books to
the shopping cart …”

17. 21
Exploration through examples
Books in catalogue:
Title Author
Specification-By-Example Gojko Adzic
Impact Mapping Gojko Adzic
Explore It! Elisabeth Hendrickson
Competitive Engineering Tom Gilb
… I want to find books in the catalogue by author and title
Search for … Books found …
Spec Specification-By-Example
Hend Explore It!
et Explore It!, Competitive Engineering
Context
Action
Assertion

18. 22
Key examples: Breaking the model
Books in catalogue:
Title Author
Specification-By-Example Gojko Adzic
Impact Mapping Gojko Adzic
Explore It! Elisabeth Hendrickson
Competitive Engineering Tom Gilb
… I want to find books in the catalogue by author and title
Search for … Books found …
Spec Specification-By-Example
Hend Explore It!
et Explore It!, Competitive Engineering
What happens, if I search for
“Explore Specification”?
Can I search for single
characters, e.g. “e”?
Is the number of search results
limited, or paged?
Is the search also performed in the
sub-title of a book?

19. 23
UI wire frames,
existing UI
rules, key examples
existing artifacts,
samples
Different kinds of examples

20. 24
Abstract acceptance criteria
As a shop visitor
I want to collect books in my shopping basket
so that I can purchase multiple books at once.
Books can be added to the shopping basket
Books can be removed from the shopping basket
Shopping basket is initially empty
The same book can be added multiple times to the shopping
basket

21. 25
Examples in Gherkin
As a shop visitor
I want to collect books in my shopping basket
so that I can purchase multiple books at once.
Books can be added to the shopping basket
Given my shopping basket is empty
When I add the book “Harry Potter” to my shopping basket
Then my shopping basket should contain 1 copy of “Harry Potter”

22. 26
As a shop visitor
I want to collect books in my shopping basket
so that I can purchase multiple books at once.
Books can be added to the shopping basket
Examples in Gherkin
Given my shopping basket contains 1 copy of “Harry Potter”
When I add the book “Harry Potter” to my shopping basket
Then my shopping basket should contain 2 copies of “Harry Potter”
The same book can be added multiple times to the shopping basket

23. 27
The same book can be added multiple times to the shopping basket
Structure of examples
Given my shopping basket contains 1 copy of “Harry Potter”
When I add the book “Harry Potter” to my shopping basket
Then my shopping basket should contain 2 copies of “Harry Potter”
Title: Describes intention/abstract acceptance criterion
Arrange: Context, describes state of the system
Act: Execution of the feature
Assert: Assertion of observable behaviour
And I should see the warning: “Book already existed in basket”
Triple-A
constraint
“Checks”
Chaining
up steps

24. 28
Purpose of the examples
• Shared understanding:
acceptance criteria
• Documentation:
system details
• Regression-tests:
violated specifications

25. 29
Automated continuous validation
Given my shopping basket contains 1 copy of “Harry Potter”
When I add the book “Harry Potter” to my shopping basket
Then my shopping basket should contain 2 copies of “Harry Potter”
System
„Step Definitions“ are binding individual steps
to an automatable interface of the application.
Automatable
interface
UI
Automation
Automation does not necessarily have to bind to the UI.
Automatability of system is supported/evolving with development.

26. 30
Demo
http://www.specflow.org
Gherkin automation for .NET
• Visual Studio plugin (VS-Gallery)
• NuGet Package

27. 32
Booking system

28. 33
Payroll calculation

29. 34
eVoting system

30. 35
Examples in Excel

31. 36
Business readable
team flow
with ATDD

32. 37
Tasks are not business readable
Create bookings for a fixed time loop on

33. 38
… but scenarios (AC) are

34. 39
ATDD cycle
Write a
failing
unit test
Make the
test pass
Refactor
Write a failing
acceptance
test
Deploy and
measure
impact
Refine feature, if needed
(new user story)
break down
units
extend
systemUser Story
AC/Scenario 1
AC/Scenario 2
AC/Scenario …
AC/Scenario n
modify
system
Expected
impact

35. 40
Business readable progress
In Progress

36. 41
Current sprint report: all sprint scenarios

37. 42
Starting with first scenario (AC)

38. 43
Finishing the first scenario (AC)

39. 44
Progressing scenario after scenario

40. 45
Progressing scenario after scenario

41. 46
Progressing scenario after scenario

42. 47
Implementing user stories in parallel

43. 48
First user story ready for testing

44. 49
Testing can start even earlier

45. 50
Already done work can break again

46. 51
Already done work can break again

47. 52
See what is temporarily not working

48. 53
Living
documentation

49. 54
Living documentation
Drill into Details
(Gherkin scenarios)
Overview
(Story Map)

50. 55
User Stories vs. Features
Product/Sprint Backlog
User Story 1
AccCrit 1
AccCrit 2
User Story 2
AccCrit 3
AccCrit 4
Living Documentation
Feature 1
AccCrit 1
AccCrit 2
Feature n
AccCrit 4
AccCrit m
User Story n
AccCrit 5
AccCrit m
AccCrit 3
AccCrit 5
„Done“
• Future options of the system
• Organized/refined according to
priority, value, effort, risk, ...
• Next possible increments of
the product (units of work)
• Current state of the system
• Organized/refined for
functional overview
• Versioned and maintained
together with source code

51. 56
Getting
started with
Specification-By-Example

52. 57
Start with the conversation
• What happens when … ?
• What would you try out … ?
• Discuss based on concrete examples

53. 58
Grow your team’s skills
• (Acceptance) Test Driven Development
• Test Automation Pyramid
• Exploratory Testing

54. 59
Decide for an automation tool
Gherkin tools available for
Ruby, Java, .NET, JavaScript, PHP, …
www.specflow.org
www.cukes.info
Other ATDD tools like:
JBehave, Fitnesse, Robotframework,
Concordion, …

55. 60
Treat test automation
as a first class citizen
• Emerging architecture
• Refactoring
• Definition of Done

56. 61
Books to read
Gojko Adzic
Bridiging the
Communication Gap
Gojko Adzic
Specification by
Example
Elisabeth Hendrickson
Explore IT!

57. Coaching

58. Coaching

59. 65

61. 69
Christian Hassa: ch@techtalk.ch - @chrishassa