A software developer gave a presentation about the importance of testing code to prevent bugs. They emphasized that all code should be tested, as even a single bug can cause problems. They recommended using tools like compilers, type checking, and annotation to detect errors early. They also suggested implementing continuous integration and automated testing to constantly check for issues. The key message was to thoroughly test all code.

1. 버그 하나 때문에...
What a bug can do
24 Jan 2019
양철웅
Chul-Woong Yang
2019 수산INT 보안연구소 개발자 워크샵

2. Speaker
● 양철웅 (Chul-Woong Yang)
● work e-mail: ycw@soosan.co.kr
● work slack, groupware: ylinux2
● SNS: cwyang
● 학교에서 (At School)
○ Database Lab: Data Mining, Web Caching
● 회사에서 (At Work)
○ Layer 4 Load-balancer (c.f. HAproxy)
○ Web cache (c.f. Squid)
○ SSL visibility (no open source alternatives)
● 사용하는 것들 (I use)
○ mint linux + xmonad (tiling manager)
○ emacs + tmux
○ 세벌식 한글 (3-beol-sik hangul)

3. Previous Customers

4. Current Customers
공공 / 금융 / 기업
Public / BFSI / Enterprise

5. What a bug can do:

6. What a bug can do:
It’s OK.
I was born
to be a loser.

7. So, What?

8. Test your code

9. Syntax Error

10. Type Error

11. “Use the force, Luke!” - Obi-Wan Kenobi
“Use the compiler (to detect unseen error)”
“Use the Typescript!” - javascript
“Use type annotation!” - python
...

12. Test all your code

13. “I took the one less traveled by,
And that has made all the difference.”
~ Robert Frost
The Path Not Taken

14. Code → Test → Check Coverage

15. Always test all your code

16. Code → Test → Push
→ Automatic Test →
Report → Code → ...

17. https://github.com/cwyang/decrypt-sslstream

18. https://travis-ci.org/
cwyang/
decrypt-sslstream

19. https://codecov.io/
gh/cwyang/
decrypt-sslstream

20. Summary
TEST Your Code
Test ALL your code
ALWAYS test all your code

21. Less bugs make us happy
“All men seek happiness. This is without
exception” - Blaise Pascal