The document outlines the schedule and format for a coderetreat event held in Milan in 2013. The event follows a repeating schedule of 45 minutes of coding, 10 minutes of review, and 5 minutes of break time across morning and afternoon sessions. Guiding principles for the event include no pressure, experimentation, mastering rather than completing tasks, refactoring, testing code, and characterizing behavior. Techniques like golden master tests and seeding random number generation are described. Example sessions provide tasks like characterizing current behavior, refactoring for a new feature, testing a specific method, removing code smells, eliminating duplication, and modifying a rule with a single line change.

1. Legacy
Coderetreat
Milano 2013
Text
10 PRINT "Hello World"
20 Go to 10

6. #lcrm13

7. Format of the Day
from 10:00 to 13:00
MORNING
from 13:00 to 14:00
LUNCH
from 14:00 to 17:00
AFTERNOON

8. 45 min coding
10 min retrospec
5 min break
Format of the Day
45’ coding
10’ review
5’ break

10. •CHALLENGE
•REPEAT
•FEEDBACK
DEEP
PRACTICE

11. NO PRESSURE
feel free to
experiment

12. NO PRESSURE
do not complete
the task but
master it

13. Practice

14. Refactoring
•AUTOMATIC
•MANUAL

15. Read Code

16. Test
Code
Characterize
Behaviour

17. Design
•BY CODE
•BY TESTS
•BY SMELLS

18. Rules

19. When you
don’t
pair
...

20. after
each
session
Pair

21. DELETE
YOUR
CODE
AFTER
EACH
SESSION

22. Playbook

23. Golden Master(aka characterization tests)
session #1

24. # suppose that our legacy code is this program called ‘game’
$ game > GOLDEN_MASTER
# after some changes we can check to see if behaviour has changed
$ game > OUT-01
$ diff GOLDEN_MASTER OUT-01
# after some other changes we check again and...
$ game > OUT-02
$ diff GOLDEN_MASTER OUT-02
# GOLDEN_MASTER and OUT-01 are the same
# GOLDEN_MASTER and OUT-02 are different -> behaviour changed
Golden Master(aka characterization tests)

25. # what about something with a random output?
$ whatthecommit
> I think I fixed a bug :-)
> for great justice.
> syntax
> LOL!
> ...
# somewhere in the code...
$ cat whatthecommit | ack -i ‘rand’
> 5: g = Random.new
> 42: messages[g.rand(NUMBER_OF_MESSAGES)]
Golden Master(aka characterization tests)

26. # sequence generators are initialized with a seed
# two random sequence generators initialized with the same
# seed are going to produce the same sequence of numbers
$ irb
1.9.3 > g = Random.new
1.9.3 > (1..10).map{g.rand(1000)}
=> [691, 362, 997, 692, 236, 532, 687, 616, 218, 702]
1.9.3 > g = Random.new
1.9.3 > (1..10).map{g.rand(1000)}
=> [865, 186, 89, 382, 894, 708, 769, 850, 452, 85]
1.9.3 > g = Random.new(1)
1.9.3 > (1..10).map{g.rand(1000)}
=> [37, 235, 908, 72, 767, 905, 715, 645, 847, 960]
1.9.3 > g = Random.new(1)
1.9.3 > (1..10).map{g.rand(1000)}
=> [37, 235, 908, 72, 767, 905, 715, 645, 847, 960]
Golden Master(aka characterization tests)

27. # we need to change the code to take somehow the seed
$ whatthecommit --seed=42
> fix the bug, for realz
> to those I leave behind, good luck!
> herping the derp
> changes
> ...
# so that with the same seed, the same code is going to
# create the same output
$ whatthecommit --seed=42
> fix the bug, for realz
> to those I leave behind, good luck!
> herping the derp
> changes
> ...
Golden Master(aka characterization tests)

28. $ git clone https://github.com/gabrielelana/trivia.git
$ cd triva
# enjoy

29. session #1
Characterize
the behaviour
of the code
with the golden
master
technique
Test Code

30. # to get the already done golden master
$ git merge golden-master

31. session #2
Refactoring & Design
Refactor the
code so that it
will be easy to
create a new
category of
questions

32. session #3
Test Code
Put under
test the
roll
method/
function

33. session #4
Read Code
Mark all the
smells in the
code. Remove
at least 3 of
them

34. session #5
Remove all the
duplication

35. session #6
Replacing the
penalty rules
should be a one
line change!