Ever felt the frustration of inheriting a codebase with introduced code that no one actually understands why they were added? Well, I get it. This is not a talk about atomic commits or how to be a git ninja. It’s a journey of understanding that we are not writing code for ourselves, and even if we’re, we are humans, we forget things. Having good commit messages on a project can be a time machine, saving hours of head-scratching when deciphering historical changes. Also, it impacts the code review process and improves day-to-day collaboration. Let’s explore the “how” we can leave some small tips for our future self or future developers that will touch our code and, most importantly, the “why” we should do it.

1. DECODING LEGACY
A JOURNEY THROUGH COMMIT MESSAGES
AIRTON ZANON

4. This talk is not about
Atomic Commits

5. This talk won’t teach you
advanced GIT tricks

6. Today we gonna talk about
Commit Messages
and their consequences on the
history of your software

7. Airton Zanon
Tech Lead at Temper
Having trouble to understand why a
change was done for 9 years
airton.dev
@airtonzanon@phpc.social

10. git status
git add
git commit
git pull
git push
git log
git checkout
git switch

11. What I thought version control was for…

13. But actually …

14. Why do we use version control?

15. Reference: https://about.gitlab.com/topics/version-control/#why-use-version-control

17. Why do I need to add a
description? Isn’t this clear
enough?

19. WTF took to months to the next commit?? 🤯

21. ?

22. Today I see that I didn’t leave a good legacy for that
company

24. Joining a new Company

25. - Commit Review Culture
Gerrit

26. git status
git add
git commit
git pull
git push
git log
git checkout
git switch
git blame
git rebase
git merge

28. Culture
- Commit messages should answer:
- What was changed?
- What problem this commit solves?
- Why are we changing this piece of code?
- Complete the sentence “If applied, this
commit will …”
- Should be reviewed just as
another piece of code

30. { WHAT }
{ WHY }

32. git status
git add
git commit
git pull
git push
git log
git checkout
git switch
git blame
git rebase
git merge
git add -p
git commit --fixup
git amend
git rebase -i
git push --force-with-lease
git bisect

33. Your software tells a
Story

34. - What is the legacy of your work? A story that you and others can understand?
or …

35. - No one thinks it will be important until it
happens to be

36. - No one thinks it will be important until it
happens to be
- We always say that we will write
documentations, but …

38. But we can actively keep track of the
changes

39. Learning the context brings empathy

41. Empathy

44. But it’s too much!

45. Start Simple
- There's no strict definition of the ideal
commit message
- Indicate a logical change, a new feature,
fixing a specific bug
- If you can’t describe the change, split in
smaller ones

46. Conventional Commits
<type>[optional scope]: <description>
[optional body]
[optional footer(s)]
https://www.conventionalcommits.org/en/v1.0.0/

47. The commitizen command line utility
https://github.com/commitizen/cz-cli

48. Resistance!

49. Self Documented Code Fallacy

50. Legacy Code

51. The
Broken Window
Theory

52. Any fool can write code that a computer can
understand. Good programmers write code
that humans can understand.
- Martin Fowler

53. Any fool can use a version control. Good
programmers try to help people in the future
to understand the current context.
- Me?!

54. Next time, take 2 or 3 minutes with your
commit message,
you might thank yourself in the future

55. Thank you!
Questions!?
airton.dev
@airtonzanon@phpc.social
https://joind.in/talk/f5023