Smell your Code!

Do you know how to smell your code? In this presentation, I try to answer the what, the why, and the how: What are code smells? Why should you care? How can you smell your code?

I gave this presentation at the IET-KFUPM Present Around The World competition (http://iet.ikfupm.com/patw2011/), for which I was the second runner-up.

Transcript

1. Smell your Code! Yaser Sulaiman 1
3. Our road map 3
4. Who? What? Why? How? 4
5. If you can take away only 1 lesson… 5
6. Don’t Repeat Yourself! 6
7. This rule is so important… 7
8. I must break it! 8
9. Don’t Repeat Yourself! 9
10. Who? What? Why? How? 10
11. “Who are you?” 11
12. A scientist, not an engineer (I probably should be doing this @ ACM, not IET) 12
21. 21 logo stolen from Kyle Usbeck
22. 22 logo by Yukihiro Matsumoto
23. “You talkin’ to me?” 23
24. Are you a software developer? 24
25. If not, do you write code? 25
26. If not, would you be remotely interested in writing cleaner code and making your life easier? 26
27. If not, you’re free to zone out 27
28. “Why should I listen to you?” 28
29. I won’t give you the “I’m a passionate software developer” BS 29
30. I’ve a terminal illness 30
31. Make that 2 terminal illnesses 31
32. Perfectionism & OCD 32
33. 33 photo by X.u.k.i
34. Who? What? Why? How? 34
35. “Code smells?! Can I smell my code?!” 35
36. 36 photo by lanceball
37. Yes you can, but not with your nose 37
38. Code smells are warning signs 38
39. 39 photo by pj_in_oz
40. They’re surface indications of deeper problems 40
41. 41 photo by BenChenowethWork
42. They’re surface indications of deeper problems 42
43. A code smell ⇏ a problem 43
44. Who? What? Why? How? 44
45. The bigger picture 45
46. Software Quality Code Quality Code Smells 46 not to scale
47. Writing HQ code should be the priority 47
48. HQ code = easy to read understand change 48
49. In the short term, HQ code may cost more 49
50. 50 photo by theresaanna
51. Easier to change ≈ less costly 51
52. In the long run, HQ code costs less 52
53. One path to cleaner code goes through code smells 53
54. Who? What? Why? How? 54
55. There’re many code smells 55
56. The following smells are just a small subset 56
57. They’re the ones that drives me crazy the most 57
58. Code Smell #1 58
59. DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code 59
60. The nastiest code smell 60
61. DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code DupIicated code 61
62. Code Smell #2 62
63. functions.With(just, way, too, many, parameters, and, then, even, some, more) 63
64. How many is too many? 64
65. Steve McConnell: > 7 ± 2 65
66. Robert C. “Uncle Bob” Martin: > 3 66
67. Code Smell #3 67
68. Not following a coding convention/standard/style consistently 68
69. 69 stolen from EmacsWiki
70. Not following a coding convention/standard/style consistently 70
71. The specifics doesn’t really matter; what matters most is consistency 71
72. Code Smell #4 72
73. // code.CommentOut(); 73
74. Don’t get me wrong 74
75. When you’re experimenting, comment code to your heart's content 75
76. Just remember to clean up after yourself 76
77. And don’t commit commented-out code 77
78. “Commented-out code is an abomination.”—Uncle Bob 78 photo used with permission of Uncle Bob
79. Commented-out code makes Uncle Bob angry 79
80. It makes me angry 80
81. 81 photo by tomazstolfa
82. Code Smell #5 82
83. // This is a comment 83 redundant
84. Who? What? Why? How? 84 Comments should focus on
85. Who? What? Why? How? 85
86. I may have come off as an a$$ 86
87. My code smells as bad as everyone else’s.. sometimes even worse 87
88. But I’m aware of my smells 88
89. I try my best to prevent them 89
90. I don’t ignore them; I deal with them 90
91. I smell my code 91
92. You should smell your code too 92
93. When you code, take note of your nose It should be open, not close For an open nose leads to an open mind And that’s the best rhyme I was able to find 93
94. If you want to sniff more… 94
95. 95 more than just code smells
96. …</presentation> <questions>… 96