Coding Dojo - Refactoring Tennis Kata

1. Coding Dojo
Refactoring
­Tennis Kata­
@AlinPandichi

2. Coding Dojo
Expectations?

3. Coding Dojo Mindset
● We are here to learn
● Safe place outside of work
● Need to slow down
● Focus on doing it right
● Non­competitive, collaborative, fun
environment

4. Practice session
● One laptop with a functional dev. env. is
connected to a projector
● Two developers pair program on the
laptop. The others are watching the code
changes.
● Every 7 minutes, one developer leaves
the laptop and the next one from the
room takes his place.

5. 4 rules of simple design
● Passes the tests
● No duplication
● Reveals intention
● Fewer elements

6. Code smells
“A surface indication that usually
corresponds to a deeper problem
in the system”
Quick to spot:
● bad names
● long method, does too much
● duplication
● dead code, etc.

7. Refactoring
“A technique for restructuring
an existing body of code,
altering its internal structure
without changing
its external behavior”

8. Small transformations
● Transformations preserving
behavior
● Small, less likely to go wrong
● System is fully working after each
change
● Verified by working tests
● Sequence of transformations
produce a significant restructuring

9. Tennis Refactoring Kata
https://github.com/emilybache/
Tennis­Refactoring­Kata

10. Retrospective
● What did you learn today?
● What happened as expected?
● What surprised you?
● What do you plan to use at work?

11. Thank you!