Test Driven Development with ABAP Unit. The SAP Inside Track Netherlands 2013 edition.

1. TDD in the ABAP World
Hendrik Neumann
#sitNL 2013
© 2013 evivax IT Consulting GmbH

2. Agenda
(1) Unit Testing & ABAP Unit
(2) Test Driven Development (TDD)
(3) Live Coding

3. Unit Testing & ABAP Unit
© 2013 evivax IT Consulting GmbH

4. Unit Testing
Definition

5. Unit Testing
Unit Testing is a method by which
individual units of source code are
tested to determine if they are fit
to use.

6. Unit Testing
Unit Testing is a method by which
individual units are e.g.ource code
fittMethods of t
Methods
Function Modules
fit Function Groups
fiMoModule Pools
Function
Functn Reports

7. Unit Testing
aim:
Find bugs early
Write once, run often
Effective Tests must be automated
solution:
xUnit Frameworks

8. xUnit Framework
Definition

9. xUnit Framework
Provides an automated solution with
no need to write the same tests
many times and no need to remember
what should be the result of each
test.

10. xUnit Framework
How does it work?

11. xUnit Framework
setup()
Create object under test
common to all tests.

12. xUnit Framework
Call Clear up
object under test
– e.g. a mess.. method
public
your
with test data.
setup()  test_method()

13. xUnit Framework
assert_*()–methods
setup()  test_method()
Verify output of object
under test using xUnit‘s
assert methods

14. xUnit Framework
Clear up
your mess..
setup()  test_method()teardown()

15. xUnit Framework
test_method()
test_method()
test_method()
setup()  test_method()teardown()
test_method()
test_method()
test_method()

16. ABAP Unit
© 2013 evivax IT Consulting GmbH

17. ABAP Unit
SAP‘s xUnit implemenation

18. ABAP Unit
Local test classes for global
development artifacts
In Reports, Function Modules and
Classes
Not acitve on production systems

19. ABAP Unit
• Tools integration:
– ABAP Workbench
– Code Inspector Integration
– ABAP Unit Browser
– ABAP Test Cockpit (ATC)
– ABAP in Eclipse

20. Test Driven Development
© 2013 evivax IT Consulting GmbH

21. Test Driven Development
When do you write your Unit Tests?
• Never
• After you wrote your code
• Before you write your code

22. Test Driven Development
When do you write your Unit Tests?
• Never
• After you wrote your code
• Before you write your code
Test Driven Development

23. Test Driven Development
Test 1st

24. Test Cycle
Test
Write a test that expresses how you’ll
use the code and what you need it to do.

25. Test Cycle
Test
Write enough code to
get the test to pass,
but no more.
Code

26. Test Cycle
Test
Refactor
Clean up the code to
remove redundancy and
improve the design.
Code

27. Test Cycle
Test
Refactor
Code

28. Test Cycle
Refactor
Code
Test

29. Test Cycle
Code
Test
Refactor

30. Test Cycle
Test
Refactor
Code

31. Code Kata: Roman Numerals
Rules:
•
•
•
•
smaller number in front of a larger number  subtraction
all else  addition
put only one smaller number in front of a larger number
ones, tens, hundreds and thousands are separate items
I
The numeral one. II is two, III is three.
V
The numeral 5. IV is 4, VI is 6, VII is 7, VIII is 8.
X
The numeral 10. IX is 9, XI is 11, etc.
L
The numeral 50. XL would be 40.
C
The numeral 100. C is short for the Latin word Centum,
but Century is eaysier to remember ;-)
D
The numeral 500.
M
The numeral 1000.

32. So Long, and Thanks for
All the Fish
Any Qs?
© 2013 evivax IT Consulting GmbH

33. Green Bar Patterns
(hidden track)
© 2013 evivax IT Consulting GmbH

34. Green Bar Patterns
Fake it till you make it
• Start with hardcoded results and
wait until tests force them to
become real

35. Green Bar Patterns
Triangulate To Abstraction
• Make the code abstract only when
you have two or more examples

36. Green Bar Patterns
Obvious Implementation
• aka Don‘t be stupid
• If you really know the right way
to implement it, do it that way