Introduzione al TDD.

1. Piccolo Coding Dojo
XPUG Milano 10 aprile 2013
Andrea Francia
http://andreafrancia.it
Thursday, April 11, 13

2. Timetable
• A short review of TDD (1pom)
• Practice with TDD (2pom)
• Retrospective (1pom)
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3. Test Driven
Development
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4. The heart of TDD
1. write a test
2. watch it fail
3. make it pass
4. repeat
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5. Example: calculator
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15. Example: file name
extension
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20. Three Rules of TDD
1. You can’t write any production code
unless is to make green a red test
2. You can’t add more code to a test than is
sufficient to make it red
3. You can’t write more production code than
is sufficient to make the test green
http://butunclebob.com/ArticleS.UncleBob.TheThreeRulesOfTdd
Thursday, April 11, 13

21. Refactoring (def ):
improving design without
changing its observable behavior.
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22. Refactoring (when)
make it
pass
write
•
another the Green
During
test
refactor
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23. Simple Design
A design is simple when:
1. pass all tests
2. contains no duplication
3. express the intent
4. minimal, nothing superfluous
http://c2.com/cgi/wiki?XpSimplicityRules
Thursday, April 11, 13

24. What is not unit test?
A test is not a unit test if:
1. It talks to a database.
2. It communicates across a network.
3. It touches the file system.
4. Requires some manual set-up
Working Effectively with Legacy Code - Michael Feathers
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26. Grazie
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27. Domande?
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28. Game of Life
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29. THE GAME OF LIFE
IS A TWO
DIMENSIONAL GRID
OF SQUARE CELLS
EACH OF WHICH IS
IN ONE OF TWO
POSSIBLE STATES
ALIVE OR DEAD
http://www.slideshare.net/gabriele.lana/coderetreat
Thursday, April 11, 13

30. AT EACH STEP IN
TIME EVERY CELL
INTERACTS WITH
ITS 8 NEIGHBORS
FOLLOWING 3
RULES
http://www.slideshare.net/gabriele.lana/coderetreat
Thursday, April 11, 13

31. 1. ANY LIVE CELL WITH FEWER THAN 2
LIVE NEIGHBORS DIES OF LONELINESS
http://www.slideshare.net/gabriele.lana/coderetreat
Thursday, April 11, 13

32. 2. ANY LIVE CELL WITH MORE
THAN 3 LIVE NEIGHBORS
DIES OF OVERCROWDING
http://www.slideshare.net/gabriele.lana/coderetreat
Thursday, April 11, 13

33. 3. ANY DEAD CELL WITH
EXACTLY 3 LIVE NEIGHBORS
COMES TO LIFE OF WARMTH
http://www.slideshare.net/gabriele.lana/coderetreat
Thursday, April 11, 13

34. LIFE EVOLUTION
1 2 3
http://www.slideshare.net/gabriele.lana/coderetreat
Thursday, April 11, 13

35. LIFE EVOLUTION
1 2 3
http://www.slideshare.net/gabriele.lana/coderetreat
Thursday, April 11, 13

36. LIFE EVOLUTION
1 2 3
http://www.slideshare.net/gabriele.lana/coderetreat
Thursday, April 11, 13