1. © Schalk W. Cronjé Bangalore July 2013
Real World TDD
Schalk W. Cronjé
@ysb33r
ysb33r@gmail.com

2. © Schalk W. Cronjé Bangalore July 2013
Following a process / using TDD
does not make your testing agile

3. © Schalk W. Cronjé Bangalore July 2013
You can accept just to do what you are told
or you can decide to be better ...
Image: http://bit.ly/12FKyID

4. © Schalk W. Cronjé Bangalore July 2013
TDD?
Test-driven Development ?
Test-driven Design ?

5. © Schalk W. Cronjé Bangalore July 2013
Myth #1
TDD is writing tests
before production code

6. © Schalk W. Cronjé Bangalore July 2013
London School of Thought
TDD is growing code,
guided by tests

7. © Schalk W. Cronjé Bangalore July 2013
Myth #2
TDD is only about writing unit tests

8. © Schalk W. Cronjé Bangalore July 2013
TDD is growing code ...
guided by
unit tests,
integration tests,
functional tests,
deployment tests

9. © Schalk W. Cronjé Bangalore July 2013
Myth #3
Test code does not have
to be well-written

10. © Schalk W. Cronjé Bangalore July 2013
The test system is as important
as the production code
http://dhemery.com/pdf/test-automation-zombie-
apocalypse.pdf

11. © Schalk W. Cronjé Bangalore July 2013
Lean Startup Exception
In short-lived production code,
don't bother with TDD
unless …
It helps you solve the problem

12. © Schalk W. Cronjé Bangalore July 2013
Myth #4
TDD is only for new code

13. © Schalk W. Cronjé Bangalore July 2013
You can decide to be better ...
need a code change?
write a test first,
ensure it passes,
break it, fix it,
make the change
add code coverage

14. © Schalk W. Cronjé Bangalore July 2013
Gärtner's Cultural Patterns of Agile Testing
Separation
Pipelining
Mini-waterfalls
Integrated
Continuous
http://www.ministryoftesting.com/2013/07/cultural-patterns-in-agile-testing/

15. © Schalk W. Cronjé Bangalore July 2013
delivered
build
Time Factors in Legacy Testing
Feature 3 Dev
Feature 2 Dev
Feature 4 Dev
Feature 1 Dev
Bug
DB
Feature 1 QA
Feature 2 QA
Feature 3 QA
Feature 4 QA
defect trickle feed
Feature 5+ Dev
Feature 5+ QA
delivered
build
Retest fixes QA
understanding
specs
time from raising defect until it is
available for testing
Building test
infrastructure
time to
re-test
basic build
verification

16. © Schalk W. Cronjé Bangalore July 2013
Test specification up front
Now everyone knows what we plan to test

17. © Schalk W. Cronjé Bangalore July 2013
Integrate Developers-Testers into pairs
Shared problem-solving leads
to reduced cycle-time
“Two are better then, because they have good reward for
their labor: If either falls down, one can help the other up.
But pity anyone who falls and has no one to help them
up”.
Ecclesiastes 4:9-10 NIV Translation
~ 971 – 931 BC

18. © Schalk W. Cronjé Bangalore July 2013
Expressive Test Style
def "'and' should join groups when the thousands multiplier is not a multiple
of one hundred" () {
expect:
EnglishNumbers.format( number ) == english_wording
where:
number | english_wording
120_000 | "one hundred and twenty thousand"
323_000 | "three hundred and twenty three thousand"
}
See also: BDD, ATDD, Specification by Example

19. © Schalk W. Cronjé Bangalore July 2013
Build a walking skeleton before
any (more) features are written
Do the difficult whilst it is easy
– Sun Tzu, “Art of War”
~ 512 BC
Image: http://bit.ly/15BTxMI

20. © Schalk W. Cronjé Bangalore July 2013
One class
One unit test
One integration test
One deployment script
Continuous Integration
Auto-deployment
Deployment-driven development

21. © Schalk W. Cronjé Bangalore July 2013
Advanced CI Orchestration
Expensive test sets should be
downstream and parallellised
http://delivervalue.blogspot.co.uk/2013/06/more-advanced-build-flows-with-
jenkins.html

22. © Schalk W. Cronjé Bangalore July 2013
Conclusion
● There is more than one way
● Think big (beyond unit tests)
● Be the one that makes the difference

23. © Schalk W. Cronjé Bangalore July 2013
Real World TDD
Schalk W. Cronjé
@ysb33r
ysb33r @ gmail.com