1. Working effectively
with legacy code
­ chapter 1 ­
2010.12.23
geek—cafe, koduki

2. What is legacy code ?

3. not object oriented ?

4. NO

5. not beautiful ?

6. NO

7. nothing test ?

8. YES

9. If tests are written,
an awful code is refactable.
However, even a wonderful code
is difficult change if there is no test.

10. 1. Changing Software.

11. Four reasons to change software
1.Adding a feature
2.Fixing a bug
3.Refactoring
4.Optimizing

12. Change reason and type
Adding a feature Fixing a bug Refactoring Optimizing
Structure change change change
New Function change
Function change
Resource change
Test Code change Change

13. Points to change
● What should I change?
● How can I confirm the change is correct?
● How can I confirm anything is not broken?

14. These are very difficult.
So we fear the change.

15. Risks by not changing
● the code becomes complex.
● skill down for changing software.
● fear of changing grows more and more.

16. To Be Continued
Chapter 2.