Clean Code - 5
- 1. Clean Code 5 A Handbook of Agile Software Craftsmanship Robert C. Martin Note by waegaein@github.com
- 2. Clean Code
- 3. The Total Cost of Owning a Mess • Over the span of a year or two, teams that were moving very fast at the beginning of a project can find themselves moving at a snail’s pace.
- 4. The Total Cost of Owning a Mess • Over the span of a year or two, teams that were moving very fast at the beginning of a project can find themselves moving at a snail’s pace. • Every change they make to the code breaks two or three other parts of the code.
- 5. The Total Cost of Owning a Mess • Over the span of a year or two, teams that were moving very fast at the beginning of a project can find themselves moving at a snail’s pace. • Every change they make to the code breaks two or three other parts of the code. • No change is trivial.
- 6. The Total Cost of Owning a Mess • Over the span of a year or two, teams that were moving very fast at the beginning of a project can find themselves moving at a snail’s pace. • Every change they make to the code breaks two or three other parts of the code. • No change is trivial. • Every addition or modification to the system requires that the tangles, twists, and knots be “understood” so that more tangles, twists, and knots can be added.
- 7. The Total Cost of Owning a Mess • As the mess build, the productivity of the team continues to decrease.
- 8. The Total Cost of Owning a Mess • As the mess build, the productivity of the team continues to decrease. • As productivity decreases, management does the only thing they can; they add more staff to the project in hopes of increasing productivity.
- 9. The Total Cost of Owning a Mess • As the mess build, the productivity of the team continues to decrease. • As productivity decreases, management does the only thing they can; they add more staff to the project in hopes of increasing productivity. • But that new staff is not versed in the design of the system.
- 10. The Total Cost of Owning a Mess • Furthermore, they, and everyone else on the team, are under horrific pressure to increase productivity.
- 11. The Total Cost of Owning a Mess • Furthermore, they, and everyone else on the team, are under horrific pressure to increase productivity. • So they all make more and more messes, driving the productivity ever further toward zero.
- 12. The Total Cost of Owning a Mess
- 13. Attitude • Have you ever waded through a mess so grave that it took weeks to do what should have taken hours?
- 14. Attitude • Have you ever waded through a mess so grave that it took weeks to do what should have taken hours? • Have you seen what should have been a one-line change, made instead in hundreds of different modules?
- 15. Attitude • Have you ever waded through a mess so grave that it took weeks to do what should have taken hours? • Have you seen what should have been a one-line change, made instead in hundreds of different modules? • These symptoms are all too common.
- 16. Attitude • Why does this happen to code?
- 17. Attitude • Why does this happen to code? • Why does good code rot so quickly into bad code?
- 18. Attitude • We have lots of explanations for it.
- 19. Attitude • We have lots of explanations for it. • We complain that the requirements changed in ways that thwart the original design.
- 20. Attitude • We have lots of explanations for it. • We complain that the requirements changed in ways that thwart the original design. • We bemoan the schedules that were too tight to do things right.
- 21. Attitude • We have lots of explanations for it. • We complain that the requirements changed in ways that thwart the original design. • We bemoan the schedules that were too tight to do things right. • We blather about stupid managers and intolerant customers and useless marketing types and telephone sanitizers.
- 22. Attitude • But the fault is not in our stars, but in ourselves.
- 23. Attitude • But the fault is not in our stars, but in ourselves. • We are unprofessional.
- 24. Attitude “But wait!” “If I don’t do what my manager says, I’ll be fired!”
- 25. Attitude “But wait!” “If I don’t do what my manager says, I’ll be fired!” • Probably not.
- 26. Attitude “But wait!” “If I don’t do what my manager says, I’ll be fired!” • Probably not. • Most managers want the truth. • Even when they don’t act like it.
- 27. Attitude “But wait!” “If I don’t do what my manager says, I’ll be fired!” • Probably not. • Most managers want the truth. • Even when they don’t act like it. • They may defend the schedule and requirements with passion; but that’s their job.
- 28. Attitude “But wait!” “If I don’t do what my manager says, I’ll be fired!” • Probably not. • Most managers want the truth. • Even when they don’t act like it. • They may defend the schedule and requirements with passion; but that’s their job. • It’s your job to defend the code with equal passion.
- 29. Attitude • A patient is complaining about doctor’s washing hands taking too long.
- 30. Attitude • A patient is complaining about doctor’s washing hands taking too long. • It would be unprofessional (never mind criminal) for the doctor to comply with the patient and give up washing hands.
- 31. Attitude • A patient is complaining about doctor’s washing hands taking too long. • It would be unprofessional (never mind criminal) for the doctor to comply with the patient and give up washing hands. • So too it is unprofessional for programmers to bend to the will of managers who don’t understand the risks of making messes.
- 32. The Boy Scout Rule Leave the campground cleaner than you found it.