Code Stinkers
                         Anonymous
                        Mark Cornick • Viget Labs
                       ...
Hello
Friday, June 12, 2009
My name is Mark,
                        and I am a code stinker.




Friday, June 12, 2009
How I got here
Friday, June 12, 2009
10 years in sysadmin
                    before becoming a developer
Friday, June 12, 2009
Mostly self-taught;
                  almost never used my CS degree




Friday, June 12, 2009
A very Brief Introduction To
                       Edsger W. Dijkstra
                        who wiquot; be quoted a few...
Edsger W.
                         Dijkstra
                   (1930-2002)
                   Notable for:
        •    Sh...
How Do We Tell Truths
                          That Might Hurt?




Friday, June 12, 2009
My Back Pages
                        Or, “I was so much lamer then;
                         I’m less lame than that now”...
BASIC




Friday, June 12, 2009
10 TEXT:HOME
                 20 GOSUB 100
                 30 END
                 100 ?“YES I JUST GOSUBBED FOR
        ...
“It is practicaquot;y impossible to teach
                        good programming style to students
                     ...
COBOL




Friday, June 12, 2009
IDENTIFICATION DIVISION.
                 PROGRAM-ID. COBOL-EXAMPLE.
                 PROCEDURE DIVISION.
                ...
“The use of COBOL cripples the
                        mind; its teaching should, therefore,
                        be re...
FORTRAN




Friday, June 12, 2009
C HAD ENOUGH YET?
                       PROGRAM UGLY
                       WRITE(UNIT=*, FMT=*) 'FORTRAN!'
             ...
“[T]he infantile disorder”, by now
                        nearly 20 years old, is hopelessly
                        inad...
Perl




Friday, June 12, 2009
#/usr/bin/env perl
                 #
                 # (Insert some convoluted JAPH
                 # code/line noise h...
Dijkstra doesn’t mention Perl,
                 but I don’t think he would have
                              liked it.


...
There’s More Than
                        One Way To Do It,
                        but many of them
                     ...
What Sysadmins
                         Do All Day
                           and how it explains
                        ...
Friday, June 12, 2009
Get it done. Put the fire out.
                       Then forget about it.
Friday, June 12, 2009
Short, quick scripts


                        #!/bin/sh
                        for year in 1996 1997 1998 1999 2000; do
...
Sysadmins aren’t agile




Friday, June 12, 2009
Sysadmins don’t do OO




Friday, June 12, 2009
Some Object-Oriented
                 Languages I Have Not Known




Friday, June 12, 2009
C++




Friday, June 12, 2009
Friday, June 12, 2009
Python




Friday, June 12, 2009
Python seemed cool to me,
                             but I didn’t get it.




Friday, June 12, 2009
Java




Friday, June 12, 2009
I never learned Java.
                               Really.




Friday, June 12, 2009
The Predicament

Friday, June 12, 2009
Bad practice
                        as a non-developer
                            carries over



Friday, June 12, 2009
Dijkstra was right:
                        I never learned good style




Friday, June 12, 2009
Code
                        Smells

Friday, June 12, 2009
The Result

Friday, June 12, 2009
My code needs a lot of
                             refactoring



Friday, June 12, 2009
Maintenance is
                           difficult



Friday, June 12, 2009
Fellow developers laugh and
                             kick sand in my face
Friday, June 12, 2009
The Goal

Friday, June 12, 2009
Write quality code
                          the first time



Friday, June 12, 2009
Minimize the need for
                             refactoring



Friday, June 12, 2009
No more sand
                        kicked in my face!
Friday, June 12, 2009
On Refactoring
                        (a brief philosophical interlude)




Friday, June 12, 2009
Refactoring:
                        improving the non-functional
                         characteristics of the code
   ...
Refactoring
            An essential part
            of a developer’s
             healthy diet.


Friday, June 12, 2009
BUT
Friday, June 12, 2009
Refactoring is like sugar.
                           It’s sweet,
                  but too much is bad for you.



Friday...
WHY?
Friday, June 12, 2009
Time spent refactoring could
                          be spent actuaquot;y coding.




Friday, June 12, 2009
Time spent refactoring could
                           be spent factoring.




Friday, June 12, 2009
I do love refactoring, but
                        I make avoiding it a goal




Friday, June 12, 2009
Writing Better Code
                        Or, “It hurts when you do that? Don’t do that.”




Friday, June 12, 2009
Number one:




Friday, June 12, 2009
TEST
Friday, June 12, 2009
No, really.




Friday, June 12, 2009
TEST!
Friday, June 12, 2009
99 out of 100
                        developers agree:
                           writing tests
                         ...
Test First
Friday, June 12, 2009
Testing Philosophies
                         And Frameworks
Friday, June 12, 2009
TDD, BDD, DDD,
                        TATFT, LMNOP.
Friday, June 12, 2009
Test::Unit, RSpec, minitest,
                             micronaut, bacon.
Friday, June 12, 2009
Fettucine, linguine,
                          martini, bikini.
Friday, June 12, 2009
I’m not going to tell you
                   which test framework to use*


                        * but I like Test::Uni...
Pick one
                        and stay with it.
Friday, June 12, 2009
Still don’t know
                  which one to use?
                          Find out what
                        your ...
At first, writing tests
                 was completely foreign to me.
Friday, June 12, 2009
Until I decided to
                        appeal to my own ego.
Friday, June 12, 2009
I like being right.
                              (Don’t you?)




Friday, June 12, 2009
Testing is an
                   automated way of
                  proving I’m right.

                  (Or, at least, t...
Proving my code correct
                      motivates me
                      to keep writing
                        g...
Be a good primate.
                         Use your tools.
Friday, June 12, 2009
Tools can help you
                        improve your code.




Friday, June 12, 2009
BUT
Friday, June 12, 2009
Tools cannot write good code
                             for you.




Friday, June 12, 2009
A Few Tools I Like
                        Or, “I got your take-home message right here”




Friday, June 12, 2009
RCov
                           gem install relevance-rcov
                        http://github.com/relevance/rcov




Fr...
Checks code coverage
                           in your tests.




Friday, June 12, 2009
Checks code coverage
                           in your tests.




Friday, June 12, 2009
Why RCov Helps
                        • To reach full coverage,
                         you write more tests.
          ...
Things To Look Out For
                        • RCov isn’t perfect.
                        • It will sometimes miss code...
Reek
                                    gem install reek
                        http://github.com/kevinrutherford/reek

...
Finds common smells
                                    in your code.
                        quot;app/controllers/applica...
Why Reek Helps
                        • Reek finds common
                         anti-patterns.
                        ...
Things To Look Out For
                        • Reek also isn’t perfect.
                        • It false-positives oft...
Let’s Talk About
                            How My Code Smells
                        Or, The Part Of The Presentation T...
MVC
                        Learn it. Know it. Live it.



Friday, June 12, 2009
Obese Controllers
Friday, June 12, 2009
Do As I Say,
                                     Not As I Did
                        Actual client project, 2007 (I am n...
xxxxx XxxxxxXxxxxxxxxx < XxxxxxxxxxxXxxxxxxxxx # redacted for public publication
                          xxxxxx_xxxxxx :...
Why???
                        • Didn’t understand the domain.
                        • Not thinking in object-oriented
 ...
What Really Goes
                             In A Controller?

                        • Code you need to respond to a
  ...
Controller Liposuction
                        • Everything in its right place.
                        • When you see you...
BIG
                   METH-
                    ODS
Friday, June 12, 2009
Finding Big Methods
                 • Too much stuff happening; too
                        many concerns
                ...
def response
           if @response.nil?
             @final_response = false
             current = source
             ...
Small Pieces,
                        Loosely Joined

Friday, June 12, 2009
Remember
             UNIX?
          Small tools doing one
            job well ⇒ small
           methods doing one
    ...
Name Methods To
                           Communicate Intent
                        thing.expires_at <
                 ...
Don’t Do Too Much
                               In A Method
                        • When you see a method getting too
 ...
def self.user_agent
             quot;Awesome App Ruby/#{RUBY_VERSION}quot;
           end

           def self.maximum_re...
Self-Review

                        • Don’t check it in if the tests fail.
                        • Use continuous integ...
Peer Review
                        • Pair-program whenever you can. Pair
                         programming comes with ...
Quality Takes
                     Time
          By law, straight bourbon
        must be aged in new, charred
          ...
Sysadmins are used
                          to fighting fires
Friday, June 12, 2009
Firefighting is
                            not
                   the way to lasting code
                           quali...
Firefighting results
                          in code that is
                           “just whiskey”
                  ...
You may not have
                two to four years,

                 but you stiquot;
                 shouldn’t rush
Fri...
Working In A
            Vacuum
                        Most of us don’t.
                        No one should.




Frida...
Ethic of
                        Reciprocity
Friday, June 12, 2009
The
                        Golden
                         Rule
Friday, June 12, 2009
Code unto others
                        as you would have them
                             code unto you.



Friday, Jun...
You hate fixing
                        other people’s
                          bad code.

Friday, June 12, 2009
Don’t make other
                 people fix yours!

Friday, June 12, 2009
One more tool:
                        Continuous Integration




Friday, June 12, 2009
Every time the code changes,
                           run the tests.




Friday, June 12, 2009
Know where a build broke
                        and who was responsible.




Friday, June 12, 2009
CI is a good idea
                        even if you work alone.




Friday, June 12, 2009
Some CI Options
                        • CruiseControl.rb,
                         cruisecontrolrb.thoughtworks.com

   ...
Let’s Wrap This Up
                        Or, “I Hope You Know This Wiquot; Go Down On Your
                             ...
Where we come from
                        influences where we go.




Friday, June 12, 2009
There’s still time to change
                           the road you’re on.
Friday, June 12, 2009
Test.
                        No matter how, just do it.




Friday, June 12, 2009
Use tools to help you,
                        not to do work for you.




Friday, June 12, 2009
Recognize anti-patterns.
                             Avoid them.




Friday, June 12, 2009
Play well with others.




Friday, June 12, 2009
Take pride in your work.
                        Appeal to your own ego.




Friday, June 12, 2009
Learn from mistakes.
                        Learn from refactoring.




Friday, June 12, 2009
Put it all together and
                        you will write better code.




Friday, June 12, 2009
The End.
                        This has been “Code Stinkers Anonymous”
                               by Mark Cornick. T...
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Code Stinkers Anonymous

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As a professional developer, especially one who works in Ruby, you hear about code quality all the time. You learn that testing your code and making it easy to maintain are the path to success. You know about TDD, BDD, TATFT and LMNOP. You learn to cycle from red to green to refactoring. We all do our best to write quality, maintainable, reusable code. We're all human, though; some of us slip, and some of us have had to work hard at preventing code smells. In this talk, I'll talk about how I learned to program, how going pro exposed flaws in my coding style, and how I'm working to improve my code quality, sharing some of my old stinky code, the better, refactored versions, and the lessons I've learned in honing my craft.

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Code Stinkers Anonymous

  1. 1. Code Stinkers Anonymous Mark Cornick • Viget Labs RubyNation • June 12, 2009 Friday, June 12, 2009
  2. 2. Hello Friday, June 12, 2009
  3. 3. My name is Mark, and I am a code stinker. Friday, June 12, 2009
  4. 4. How I got here Friday, June 12, 2009
  5. 5. 10 years in sysadmin before becoming a developer Friday, June 12, 2009
  6. 6. Mostly self-taught; almost never used my CS degree Friday, June 12, 2009
  7. 7. A very Brief Introduction To Edsger W. Dijkstra who wiquot; be quoted a few times in the next few slides Friday, June 12, 2009
  8. 8. Edsger W. Dijkstra (1930-2002) Notable for: • Shortest path algorithm • Reverse Polish notation • Being a curmudgeon Friday, June 12, 2009
  9. 9. How Do We Tell Truths That Might Hurt? Friday, June 12, 2009
  10. 10. My Back Pages Or, “I was so much lamer then; I’m less lame than that now” Friday, June 12, 2009
  11. 11. BASIC Friday, June 12, 2009
  12. 12. 10 TEXT:HOME 20 GOSUB 100 30 END 100 ?“YES I JUST GOSUBBED FOR NO REASON WHATSOEVER” 110 RETURN Friday, June 12, 2009
  13. 13. “It is practicaquot;y impossible to teach good programming style to students that have had prior exposure to BASIC: as potential programmers they are mentaquot;y mutilated beyond hope of regeneration.” – Edsger W. Dijkstra Friday, June 12, 2009
  14. 14. COBOL Friday, June 12, 2009
  15. 15. IDENTIFICATION DIVISION. PROGRAM-ID. COBOL-EXAMPLE. PROCEDURE DIVISION. MAIN. IF YEAR <= 1991 DISPLAY 'COBOL! Argh!'. STOP RUN. Friday, June 12, 2009
  16. 16. “The use of COBOL cripples the mind; its teaching should, therefore, be regarded as a criminal offense.” – Edsger W. Dijkstra Friday, June 12, 2009
  17. 17. FORTRAN Friday, June 12, 2009
  18. 18. C HAD ENOUGH YET? PROGRAM UGLY WRITE(UNIT=*, FMT=*) 'FORTRAN!' END Friday, June 12, 2009
  19. 19. “[T]he infantile disorder”, by now nearly 20 years old, is hopelessly inadequate for whatever computer application you have in mind today: it is now too clumsy, too risky, and too expensive to use.” – Edsger W. Dijkstra Friday, June 12, 2009
  20. 20. Perl Friday, June 12, 2009
  21. 21. #/usr/bin/env perl # # (Insert some convoluted JAPH # code/line noise here.) Friday, June 12, 2009
  22. 22. Dijkstra doesn’t mention Perl, but I don’t think he would have liked it. Friday, June 12, 2009
  23. 23. There’s More Than One Way To Do It, but many of them are Wrong Friday, June 12, 2009
  24. 24. What Sysadmins Do All Day and how it explains the code they write Friday, June 12, 2009
  25. 25. Friday, June 12, 2009
  26. 26. Get it done. Put the fire out. Then forget about it. Friday, June 12, 2009
  27. 27. Short, quick scripts #!/bin/sh for year in 1996 1997 1998 1999 2000; do rm -rf backups/${year} done echo quot;Sorry, all backups from the pretend Internet money era have been purged.quot; | /usr/ucb/Mail -s quot;Your restore requestquot; boss@example.com Friday, June 12, 2009
  28. 28. Sysadmins aren’t agile Friday, June 12, 2009
  29. 29. Sysadmins don’t do OO Friday, June 12, 2009
  30. 30. Some Object-Oriented Languages I Have Not Known Friday, June 12, 2009
  31. 31. C++ Friday, June 12, 2009
  32. 32. Friday, June 12, 2009
  33. 33. Python Friday, June 12, 2009
  34. 34. Python seemed cool to me, but I didn’t get it. Friday, June 12, 2009
  35. 35. Java Friday, June 12, 2009
  36. 36. I never learned Java. Really. Friday, June 12, 2009
  37. 37. The Predicament Friday, June 12, 2009
  38. 38. Bad practice as a non-developer carries over Friday, June 12, 2009
  39. 39. Dijkstra was right: I never learned good style Friday, June 12, 2009
  40. 40. Code Smells Friday, June 12, 2009
  41. 41. The Result Friday, June 12, 2009
  42. 42. My code needs a lot of refactoring Friday, June 12, 2009
  43. 43. Maintenance is difficult Friday, June 12, 2009
  44. 44. Fellow developers laugh and kick sand in my face Friday, June 12, 2009
  45. 45. The Goal Friday, June 12, 2009
  46. 46. Write quality code the first time Friday, June 12, 2009
  47. 47. Minimize the need for refactoring Friday, June 12, 2009
  48. 48. No more sand kicked in my face! Friday, June 12, 2009
  49. 49. On Refactoring (a brief philosophical interlude) Friday, June 12, 2009
  50. 50. Refactoring: improving the non-functional characteristics of the code without screwing up the functional parts. Friday, June 12, 2009
  51. 51. Refactoring An essential part of a developer’s healthy diet. Friday, June 12, 2009
  52. 52. BUT Friday, June 12, 2009
  53. 53. Refactoring is like sugar. It’s sweet, but too much is bad for you. Friday, June 12, 2009
  54. 54. WHY? Friday, June 12, 2009
  55. 55. Time spent refactoring could be spent actuaquot;y coding. Friday, June 12, 2009
  56. 56. Time spent refactoring could be spent factoring. Friday, June 12, 2009
  57. 57. I do love refactoring, but I make avoiding it a goal Friday, June 12, 2009
  58. 58. Writing Better Code Or, “It hurts when you do that? Don’t do that.” Friday, June 12, 2009
  59. 59. Number one: Friday, June 12, 2009
  60. 60. TEST Friday, June 12, 2009
  61. 61. No, really. Friday, June 12, 2009
  62. 62. TEST! Friday, June 12, 2009
  63. 63. 99 out of 100 developers agree: writing tests leads to writing better code Friday, June 12, 2009
  64. 64. Test First Friday, June 12, 2009
  65. 65. Testing Philosophies And Frameworks Friday, June 12, 2009
  66. 66. TDD, BDD, DDD, TATFT, LMNOP. Friday, June 12, 2009
  67. 67. Test::Unit, RSpec, minitest, micronaut, bacon. Friday, June 12, 2009
  68. 68. Fettucine, linguine, martini, bikini. Friday, June 12, 2009
  69. 69. I’m not going to tell you which test framework to use* * but I like Test::Unit with Shoulda and Factory Girl Friday, June 12, 2009
  70. 70. Pick one and stay with it. Friday, June 12, 2009
  71. 71. Still don’t know which one to use? Find out what your peers use, and use that one. Friday, June 12, 2009
  72. 72. At first, writing tests was completely foreign to me. Friday, June 12, 2009
  73. 73. Until I decided to appeal to my own ego. Friday, June 12, 2009
  74. 74. I like being right. (Don’t you?) Friday, June 12, 2009
  75. 75. Testing is an automated way of proving I’m right. (Or, at least, that my code is.) Friday, June 12, 2009
  76. 76. Proving my code correct motivates me to keep writing good code. Friday, June 12, 2009
  77. 77. Be a good primate. Use your tools. Friday, June 12, 2009
  78. 78. Tools can help you improve your code. Friday, June 12, 2009
  79. 79. BUT Friday, June 12, 2009
  80. 80. Tools cannot write good code for you. Friday, June 12, 2009
  81. 81. A Few Tools I Like Or, “I got your take-home message right here” Friday, June 12, 2009
  82. 82. RCov gem install relevance-rcov http://github.com/relevance/rcov Friday, June 12, 2009
  83. 83. Checks code coverage in your tests. Friday, June 12, 2009
  84. 84. Checks code coverage in your tests. Friday, June 12, 2009
  85. 85. Why RCov Helps • To reach full coverage, you write more tests. • As you write more tests, you fix more problems. • As you fix more problems, you write better code! Friday, June 12, 2009
  86. 86. Things To Look Out For • RCov isn’t perfect. • It will sometimes miss code that is covered. • It is easy to cheat. • Just because it’s covered doesn’t mean the code is awesome. Friday, June 12, 2009
  87. 87. Reek gem install reek http://github.com/kevinrutherford/reek Friday, June 12, 2009
  88. 88. Finds common smells in your code. quot;app/controllers/application_controller.rbquot; -- 3 warnings: ApplicationController#username_for calls user.username multiple times (Duplication) ApplicationController#username_for doesn't depend on instance state (Utility Function) ApplicationController#username_for refers to user more than self (Feature Envy) quot;app/controllers/groups_controller.rbquot; -- 5 warnings: GroupsController#show calls params multiple times (Duplication) GroupsController#show calls params[:page] multiple times (Duplication) GroupsController#show calls params[:page].to_i multiple times (Duplication) GroupsController#show has approx 6 statements (Long Method) GroupsController#show/block/block is nested (Nested Iterators) quot;app/controllers/sessions_controller.rbquot; -- 2 warnings: SessionsController#create calls flash multiple times (Duplication) SessionsController#create has approx 8 statements (Long Method) quot;app/controllers/user_feeds_controller.rbquot; -- 3 warnings: UserFeedsController#create calls logger multiple times (Duplication) UserFeedsController#create has approx 6 statements (Long Method) UserFeedsController#create has the variable name 'e' (Uncommunicative Name) quot;app/helpers/application_helper.rbquot; -- 14 warnings: ApplicationHelper::feed_date_for doesn't depend on instance state (Utility Function) ApplicationHelper::feed_date_for refers to date more than self (Feature Envy) ApplicationHelper::feedstitch_group_for doesn't depend on instance state (Utility Function) ApplicationHelper::feedstitch_group_for refers to user more than self (Feature Envy) ApplicationHelper::link_to_group_feed has 4 parameters (Long Parameter List) Friday, June 12, 2009 ApplicationHelper::name_for doesn't depend on instance state (Utility Function)
  89. 89. Why Reek Helps • Reek finds common anti-patterns. • Anti-patterns are bad habits that are worth breaking. • Fewer bad habits == better code! Friday, June 12, 2009
  90. 90. Things To Look Out For • Reek also isn’t perfect. • It false-positives often. • It can only make suggestions. • It doesn’t catch all possible code smells. Friday, June 12, 2009
  91. 91. Let’s Talk About How My Code Smells Or, The Part Of The Presentation That Is Potentiaquot;y Very Embarrassing To The Presenter Friday, June 12, 2009
  92. 92. MVC Learn it. Know it. Live it. Friday, June 12, 2009
  93. 93. Obese Controllers Friday, June 12, 2009
  94. 94. Do As I Say, Not As I Did Actual client project, 2007 (I am not making this up): • One controller • One method • ~130 LOC • Actual comment: # OPTIMIZE: this is ugly Friday, June 12, 2009
  95. 95. xxxxx XxxxxxXxxxxxxxxx < XxxxxxxxxxxXxxxxxxxxx # redacted for public publication xxxxxx_xxxxxx :xxxxx_xxx_xxxx xxxxxx_xxxxxx :xxxxxxx_xxx_xx_xxxxxxx, :xxxx => [:xxxx]‚Ä® xxx xxxx xxxxxx.xxxxxx(:xx_xxx_xxxxxxx) xxxxxx[:xxxxxx] ||= Xxxxxxx::XXXXXX_XXXXXX @xxxxxxx_xxxxxxx = xxxxxx.xxxxxx(:xxxxxxx_xxxxxxx) xx xxxxxx[:xxxxxxxx_xxxx_xxxxxxx].xxx? @xxxx_xxxxxxxxxx_xxx_xxxxxxx = xxxx xxxx @xxxx_xxxxxxxxxx_xxx_xxxxxxx = xxxxxx[:xxxxxxxx_xxxx_xxxxxxx].xxxxxxx?(quot;xxxx_xxxxxxxxxxquot;) xx @xxxx_xxxxxxxxxx_xxx_xxxxxxx xxxxxx[:xxxxxxxx_xxxx_xxxxxxx].xxxxxx(quot;xxxx_xxxxxxxxxxquot;) xxxxxxxx_xxxxxx = Xxxx[*xxxxxxx[:xxxxxx]['xxxxxxxx_xxxx_xxxxx']] xx xxxxxxxx_xxxxxx.xxxxxx > 9 xxxxxxxx_xxxxxx.xxxx{|x,x| x[1] <=> x[1]}[9..-1].xxxx xx |x| xxxxxx[:xxxxxxxx_xxxx_xxxxxxx] << x[0] xxx xxx xxx xxx‚Ä® xx xxxxxx[:xxxx_xxxxxxx].xxx? @xxxx_xxxxxx_xxx_xxxxxxx = xxxx xxxx @xxxx_xxxxxx_xxx_xxxxxxx = xxxxxx[:xxxx_xxxxxxx].xxxxxxx?(quot;xxxx_xxxxxxquot;) xx @xxxx_xxxxxx_xxx_xxxxxxx xxxxxx[:xxxx_xxxxxxx].xxxxxx(quot;xxxx_xxxxxxquot;) xxxx_xxxxxx = Xxxx[*xxxxxxx[:xxxxxx]['xxxx_xxxxx']] xx xxxx_xxxxxx.xxxxxx > 19 xxxx_xxxxxx.xxxx{|x,x| x[1] <=> x[1]}[19..-1].xxxx xx |x| xxxxxx[:xxxx_xxxxxxx] << x[0] xxx xxx xxx xxx‚Ä® @xxxxxx = xxxxxxx_xxxxxx(xxxxxx[:xxxxxxxx]) xxxxxx @xxxxxx.xxx? xxxxxx[:xxxxxxxx] = xxxxxxxxxx_xxxxxxx(@xxxxxx) xxxxxxx_xxxxxx(:xxxxxx => xxxxxx[:xxxxxx], :xxxxxx_xxx => xxxxxx[:xxxxxx_xxx], :xx_xxxxxxxx => xxxxxx[:xx_xxxxxxxx], :xxxxx => xxxx, :xxxxxx => xxxxxx[:xxxxxx].xx_x) xxxx xxxxx[:xxxxxx] = quot;Xxxxxxx xxxxxxxx, xxxxxx xxx xxxx xxxxxx xxxxx.quot; @xxxxxxxx = [].xxxxxxxx(:xxxx => 1) xxx @xxxx_xxxxxxx = @xxxxxxxx[0,3] @xxxxxxxxxx_xxxxxxx = (@xxxxxxxx[3,(Xxxxxxx.xxx_xxxx - 3)] || []) @xxxxxxxx = @xxxxxxxx.xxxxxx xx @xxxxxxxx.xxxxxxx_xx?(:xxxxxx) && !@xxxxxxxx.xxxxxx.xxx? && !@xxxxxxxx.xxxxxx.xxxxx? @xxxxx_xxxxxx = Xxxx[*@xxxxxxxx.xxxxxx['xxxxx_xxxxx']] @xxxx_xxxxxx = Xxxx[*@xxxxxxxx.xxxxxx['xxxx_xxxxx']] @xxxxxxxx_xxxx_xxxxxx = Xxxx[*@xxxxxxxx.xxxxxx['xxxxxxxx_xxxx_xxxxx']] xxxxxx_xxxxx_xxxxxx = Xxxx[*xxxxxxx[:xxxxxx]['xxxxx_xxxxx']] xxxxxx_xxxx_xxxxxx = Xxxx[*xxxxxxx[:xxxxxx]['xxxx_xxxxx']] xxxxxx_xxxxxxxx_xxxx_xxxxxx = Xxxx[*xxxxxxx[:xxxxxx]['xxxxxxxx_xxxx_xxxxx']]‚Ä® xxxxxx_xxxxx_xxxxxx.xxxx xx |x,x| @xxxxx_xxxxxx[x] = 0 xxxxxx @xxxxx_xxxxxx.xxx_xxx?(x) xxx xxxxxx_xxxx_xxxxxx.xxxx xx |x,x| @xxxx_xxxxxx[x] = 0 xxxxxx @xxxx_xxxxxx.xxx_xxx?(x) xxx xxxxxx_xxxxxxxx_xxxx_xxxxxx.xxxx xx |x,x| @xxxxxxxx_xxxx_xxxxxx[x] = 0 xxxxxx @xxxxxxxx_xxxx_xxxxxx.xxx_xxx?(x) xxx‚Ä® @xxxxx_xxxxxx = @xxxxx_xxxxxx.xxxx # OPTIMIZE: this is ugly @xxxx_xxxxxx = @xxxx_xxxxxx.xxxx{|x,x| quot;#{xxxxxxx('%09x',xxxxxx_xxxx_xxxxxx[x[0]])} #{x[0]}quot; <=> quot;#{xxxxxxx('%09x',xxxxxx_xxxx_xxxxxx[x[0]])} #{x[0]}quot;} @xxxxxxxx_xxxx_xxxxxx = @xxxxxxxx_xxxx_xxxxxx.xxxx{|x,x| quot;#{xxxxxxx('%09x',xxxxxx_xxxxxxxx_xxxx_xxxxxx[x[0]])} #{x[0]}quot; <=> quot;#{xxxxxxx('%09x',xxxxxx_xxxxxxxx_xxxx_xxxxxx[x[0]])} #{x[0]}quot;}‚Ä® @xxxxxxxx_xxxxxx = @xxxxxxxx.xxxxxx xxxxxxxx_xxx = [] xxxxxxxx_xxx = [] xxxxxx xxxxxxx[:xxxxxx]['xxxxxxxx_xxxxx_xxxxx'].xxx? xxxxxxxx_xxx = Xxxx[*xxxxxxx[:xxxxxx]['xxxxxxxx_xxxxx_xxxxx']].xxxxxx_xx{|x,x| x.xxxxx?}.xxxxxxx{|x,x| x.xx_x} xxx xxxxxx xxxxxxx[:xxxxxx]['xxxxxxxx_xxxxx_xxxxx'].xxx? xxxxxxxx_xxx = Xxxx[*xxxxxxx[:xxxxxx]['xxxxxxxx_xxxxx_xxxxx']].xxxxxx_xx{|x,x| x.xxxxx?}.xxxxxxx{|x,x| x.xx_x} xxx xxxxxxx_xxxxxxx = [] (xxxxxxxx_xxx+xxxxxxxx_xxx).xxxx xx |xxx| xxxxx xxxxxxx_xxxxxxx << Xxxxxx.xxxx(xxx) xxxxxx XxxxxxXxxxxx::XxxxxxXxxXxxxx @xxxxxxxx.xxxx{|x| x.xxxxx_xxx_xxxxx} xxx xxx @xxxxxxx = @xxxxxxx_xxxx.xxxxxxx_xxxxxxx.xxxxxx{|xx| xxxxxxx_xxxxxxx.xxxxxxx?(xx.xxxxxx) && xx.xxxxxx.xxxxxxxxxx_xxxx=='Xxxx' && @xxxxxxx_xxxx.xxxxxxxx_xxx_xxxxxxx_xxxx.xxxxxxx? (xx.xxxxxx.xxxxxxxxxx.xxxxxxxx_xxx)} @xxx_xxxxxxx = @xxxxxxx_xxxx.xxxxxxx_xxxxxxx.xxxxxx{|xx| xxxxxxx_xxxxxxx.xxxxxxx?(xx.xxxxxx) && (xx.xxxxxx.xxxxxxxxxx_xxxx!='Xxxx' || !@xxxxxxx_xxxx.xxxxxxxx_xxx_xxxxxxx_xxxx.xxxxxxx? (xx.xxxxxx.xxxxxxxxxx.xxxxxxxx_xxx))} xxxx_xxxxxxx_xxx = @xxxxxxx.xxxxxxx{|xx| xx.xxxxxx.xx} & (xxxxxx[:xxxxxx_xxx] || []).xxxxxxx{|xx| xx.xx_x} xxxx_xxx_xxxxxxx_xxx = @xxx_xxxxxxx.xxxxxxx{|xx| xx.xxxxxx.xx} & (xxxxxx[:xxxxxx_xxx] || []).xxxxxxx{|xx| xx.xx_x} @xxxx_xxxxxxx_xxxxx = xxxx_xxxxxxx_xxx.xxxxxx @xxxx_xxx_xxxxxxx_xxxxx = xxxx_xxx_xxxxxxx_xxx.xxxxxx @xxxx_xxxxxx_xxx = xxxx_xxxxxxx_xxx + xxxx_xxx_xxxxxxx_xxx @xxxxxxx.xxxx!{|x,x| (@xxxx_xxxxxx_xxx.xxxxxxx?(x.xxxxxx_xx) ? 1 : 0) <=> (@xxxx_xxxxxx_xxx.xxxxxxx?(x.xxxxxx_xx) ? 1 : 0)} @xxx_xxxxxxx.xxxx!{|x,x| (@xxxx_xxxxxx_xxx.xxxxxxx?(x.xxxxxx_xx) ? 1 : 0) <=> (@xxxx_xxxxxx_xxx.xxxxxxx?(x.xxxxxx_xx) ? 1 : 0)} @xxx_xxxxxxx = xxxxxxx_xxxxxxx - ([@xxxxxxx_xxxx.xxxxxx] + @xxxxxxx.xxxxxxx{|x| x.xxxxxx} + @xxx_xxxxxxx.xxxxxxx{|xx| xx.xxxxxx}) @xxx_xxxxxxx = @xxx_xxxxxxx.xxxxxx{|x| x.xxxxxxxxxx_xxxx == 'Xxxxxxx'} @xxx_xxxxxxx.xxxx!{|x,x| (x.xxxxxxxxxx_xxxx=='Xxxxx' ? 1 : 0) <=> (x.xxxxxxxxxx_xxxx=='Xxxxx' ? 1 : 0)} @xxx_xxxxxxx = @xxx_xxxxxxx[0,3] xxxx @xxxxx_xxxxxx = [] @xxxx_xxxxxx = [] @xxxxxxxx_xxxx_xxxxxx = [] @xxxxxxxx_xxxxxx = [] @xxxxxxx = [] @xxx_xxxxxxx = [] @xxxx_xxxxxx_xxx = [] @xxx_xxxxxxx = [] @xxxx_xxxxxxx_xxxxx = 0 @xxxx_xxx_xxxxxxx_xxxxx = 0 xxx @xxxxxxx_xxxxxxxx_xxxxxxx = [] @xxxxxxx_xxxx_xxxxxxx = [] @xxxxxxx_xxxxx_xxxxxxx = [] xx xxxxxx[:xxxxxxxx_xxxx_xxxxxxx] && xxxxxx[:xxxxxxxx_xxxx_xxxxxxx].xxxx.xxxxxx != @xxxxxxxx_xxxx_xxxxxx.xxxxxx @xxxxxxx_xxxxxxxx_xxxxxxx = xxxxxx[:xxxxxxxx_xxxx_xxxxxxx] xxx xx xxxxxx[:xxxx_xxxxxxx] && xxxxxx[:xxxx_xxxxxxx].xxxx.xxxxxx != @xxxx_xxxxxx.xxxxxx @xxxxxxx_xxxx_xxxxxxx = xxxxxx[:xxxx_xxxxxxx] xxx xx xxxxxx[:xxxxx_xxxxxxx] && xxxxxx[:xxxxx_xxxxxxx].xxxx.xxxxxx != @xxxxx_xxxxxx.xxxxxx @xxxxxxx_xxxxx_xxxxxxx = xxxxxx[:xxxxx_xxxxxxx] xxx xx @xxxxxxx_xxxxxxxx_xxxxxxx.xxxxx? && @xxxxxxx_xxxx_xxxxxxx.xxxxx? && @xxxxxxx_xxxxx_xxxxxxx.xxxxx? xxxxxx [xxxxxx[:xxxxxxxx_xxxx_xxxxxxx],xxxxxx[:xxxx_xxxxxxx],xxxxxx[:xxxxx_xxxxxxx]] == [xxx,xxx,xxx] @xxxxxxx_xxxxxxx = xxxx xxx xxx xxx xxx‚Ä® Friday, June 12, 2009
  96. 96. Why??? • Didn’t understand the domain. • Not thinking in object-oriented paradigm. • Not thinking in MVC. • Not pairing. • Lousy tests. Friday, June 12, 2009
  97. 97. What Really Goes In A Controller? • Code you need to respond to a web request and render the result • Not business logic • Not complex operations on objects Friday, June 12, 2009
  98. 98. Controller Liposuction • Everything in its right place. • When you see yourself doing business logic, move it to the model! • When you see yourself defining view logic, move it to the view/ helper! Friday, June 12, 2009
  99. 99. BIG METH- ODS Friday, June 12, 2009
  100. 100. Finding Big Methods • Too much stuff happening; too many concerns • Too many LOC to comprehend in a glance • Logic inside logic Friday, June 12, 2009
  101. 101. def response if @response.nil? @final_response = false current = source path = source.query.nil? ? source.path : quot;#{source.path}?#{source.query}quot; until @final_response Net::HTTP.start(current.host, current.port) do |http| @response = http.get(path, 'User-Agent' => user_agent) if @response.header['location'] current = URI.parse(@response.header['location']) path = current.query.nil? ? current.path : quot;#{current.path}?#{current.query}quot; else @final_response = true end end end end @response end Friday, June 12, 2009
  102. 102. Small Pieces, Loosely Joined Friday, June 12, 2009
  103. 103. Remember UNIX? Small tools doing one job well ⇒ small methods doing one job well Friday, June 12, 2009
  104. 104. Name Methods To Communicate Intent thing.expires_at < Time.now thing.expired? user.has_accepted_terms && !user.suspended user.can_sign_in? Friday, June 12, 2009
  105. 105. Don’t Do Too Much In A Method • When you see a method getting too long, break it into smaquot;er methods. • Hint: look for excessive indentation and nested ifs. • Hint: a method shouldn’t come close to filling your editor window. Friday, June 12, 2009
  106. 106. def self.user_agent quot;Awesome App Ruby/#{RUBY_VERSION}quot; end def self.maximum_redirects 4 end def initialize(url) @url = url end def endpoint_for(uri) endpoint = uri.path.sub(/^/?$/, '/') endpoint += quot;?#{uri.query}quot; unless uri.query.blank? endpoint end def fetch(url, redirects_remaining) return if redirects_remaining == 0 begin uri = URI.parse(url) response = Net::HTTP.start(uri.host, uri.port) do |http| http.get(endpoint_for(uri), {'User-Agent' => self.class.user_agent}) end if response.is_a?(Net::HTTPRedirection) response = fetch(response['location'], redirects_remaining - 1) end rescue URI::InvalidURIError RAILS_DEFAULT_LOGGER.warn quot;Error parsing URL: '#{url}'quot; end response end def response @response ||= fetch(@url, self.class.maximum_redirects) end Friday, June 12, 2009
  107. 107. Self-Review • Don’t check it in if the tests fail. • Use continuous integration to keep yourself honest. (more on this later) • Look over all your changes before you commit. • If you miss something and you’re using Git, fix it and git commit --amend Friday, June 12, 2009
  108. 108. Peer Review • Pair-program whenever you can. Pair programming comes with built-in peer review. • Do regular code reviews with your peers. During active development, weekly is good. • Listen to criticism. Don’t take it personaquot;y. No one’s perfect. Friday, June 12, 2009
  109. 109. Quality Takes Time By law, straight bourbon must be aged in new, charred oak barrels for at least two years. Anything less yields just whiskey, not bourbon. Friday, June 12, 2009
  110. 110. Sysadmins are used to fighting fires Friday, June 12, 2009
  111. 111. Firefighting is not the way to lasting code quality. Friday, June 12, 2009
  112. 112. Firefighting results in code that is “just whiskey” (and maybe not even that) Friday, June 12, 2009
  113. 113. You may not have two to four years, but you stiquot; shouldn’t rush Friday, June 12, 2009
  114. 114. Working In A Vacuum Most of us don’t. No one should. Friday, June 12, 2009
  115. 115. Ethic of Reciprocity Friday, June 12, 2009
  116. 116. The Golden Rule Friday, June 12, 2009
  117. 117. Code unto others as you would have them code unto you. Friday, June 12, 2009
  118. 118. You hate fixing other people’s bad code. Friday, June 12, 2009
  119. 119. Don’t make other people fix yours! Friday, June 12, 2009
  120. 120. One more tool: Continuous Integration Friday, June 12, 2009
  121. 121. Every time the code changes, run the tests. Friday, June 12, 2009
  122. 122. Know where a build broke and who was responsible. Friday, June 12, 2009
  123. 123. CI is a good idea even if you work alone. Friday, June 12, 2009
  124. 124. Some CI Options • CruiseControl.rb, cruisecontrolrb.thoughtworks.com • Integrity, integrityapp.com • RunCodeRun (hosted!), runcoderun.com • runcoderun.com/mcornick Friday, June 12, 2009
  125. 125. Let’s Wrap This Up Or, “I Hope You Know This Wiquot; Go Down On Your Permanent Record” Friday, June 12, 2009
  126. 126. Where we come from influences where we go. Friday, June 12, 2009
  127. 127. There’s still time to change the road you’re on. Friday, June 12, 2009
  128. 128. Test. No matter how, just do it. Friday, June 12, 2009
  129. 129. Use tools to help you, not to do work for you. Friday, June 12, 2009
  130. 130. Recognize anti-patterns. Avoid them. Friday, June 12, 2009
  131. 131. Play well with others. Friday, June 12, 2009
  132. 132. Take pride in your work. Appeal to your own ego. Friday, June 12, 2009
  133. 133. Learn from mistakes. Learn from refactoring. Friday, June 12, 2009
  134. 134. Put it all together and you will write better code. Friday, June 12, 2009
  135. 135. The End. This has been “Code Stinkers Anonymous” by Mark Cornick. Thank you! http://objectsinmirrors.com/ http://twitter.com/mcornick Please rate this talk on SpeakerRate! http://speakerrate.com/talks/1170 Friday, June 12, 2009
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