Loving Legacy Code

Are you approaching the challenge of working with legacy code with helpful techniques and a good attitude?

Accompanying blog post at http://keithpitty.com/blog/archives/2015-02-06-loving-legacy-code

Presented at RubyConf Australia on 5 February, 2015.

Transcript

1. Loving Legacy Code
   Keith Pitty
   

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2. Loving legacy code?
   

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3. Seriously?
   

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4. Do you love legacy code?
   

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5. Legacy deserves respect!
   

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6. More love!
   

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7. Approach
   Techniques
   Attitude
   

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8. What is legacy code?
   

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9. No tests?
   What is legacy code?
   

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10. Impedes change
    What is legacy code?
    

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11. Why so negative?
    

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12. Technical debt?
    Why so negative?
    

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13. Poor design
    Why so negative?
    

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14. Obfuscation
    Why so negative?
    

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15. Counterproductive tests
    Why so negative?
    

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16. No “shiny” tech?
    Why so negative?
    

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17. Tender loving care
    

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18. OK, maybe beyond TLC
    

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19. Or maybe not …
    

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20. Original developers?
    

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21. Understand why
    Original developers?
    

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22. Respect
    Original developers?
    

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23. Learn from mistakes
    Original developers?
    

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24. Approach
    Techniques
    Attitude
    

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25. Pain points
    

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26. Customer feedback
    Pain points
    

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27. Monitoring tools
    Pain points
    

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28. Listen to developers
    Pain points
    

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29. Measure code quality
    Pain points
    

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30. Nursing legacy code
    

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31. Version control!
    Nursing legacy code
    

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32. Testing
    

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33. No tests?
    Nursing legacy code: testing
    

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34. Unit tests
    Nursing legacy code: testing
    

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35. Fast feedback
    Nursing legacy code: testing
    

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36. Break dependencies
    Nursing legacy code: testing
    

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37. Nurture tests
    Nursing legacy code: testing
    

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38. Remove tests?
    Nursing legacy code: testing
    

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39. Nurture CI builds
    Nursing legacy code: testing
    

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40. Refactoring
    

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41. Refactor judiciously
    Nursing legacy code: refactoring
    

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42. Separate concerns
    Nursing legacy code: refactoring
    

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43. e.g. Rails models
    Nursing legacy code: refactoring
    

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44. Nursing legacy code
    

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45. Service classes
    Nursing legacy code: refactoring
    

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46. “Best” Practices
    Nursing legacy code: refactoring
    

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47. Simplify design
    Nursing legacy code: refactoring
    

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48. 1. Tests pass
    2. Expresses intent
    3. No duplication
    4. Small
    Nursing legacy code: refactoring
    

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49. “Remove duplication and
    improve names in small cycles.”
    — JB Rainsberger
    Nursing legacy code: refactoring
    

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50. Less code
    Nursing legacy code: refactoring
    

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51. Satisfaction
    Nursing legacy code: refactoring
    

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52. Design Opportunities
    Nursing legacy code: refactoring
    

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53. Tool support
    

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54. Nursing legacy code: tool support
    

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55. RuboCop
    Nursing legacy code: tool support
    

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56. Other open source
    Section
    

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57. Automate workflow
    Nursing legacy code: tool support
    

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58. Managing legacy code
    

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59. Invest wisely
    Managing legacy code
    

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60. Maintenance effort
    Managing legacy code
    

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61. Maintenance budget
    Managing legacy code
    

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62. If necessary …
    Managing legacy code
    

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63. migrate away
    Managing legacy code
    

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64. Approach
    Techniques
    Attitude
    

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65. Approach
    Techniques
    Attitude
    

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66. Managers
    

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67. Devote resources
    Managers
    

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68. Listen to developers
    Managers
    

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69. Respect
    Managers
    

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70. Share support roles
    Managers
    

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71. Developers
    

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72. Share knowledge
    Developers
    

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73. GitHub PRs
    Developers
    

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74. Future
    Developers
    

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75. Language
    Developers
    

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76. Respect past
    Developers
    

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77. No codebase is perfect
    Developers
    

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78. Listen to managers
    Developers
    

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79. Respect
    Developers
    

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80. Metaphors
    

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81. Nursing
    Metaphors
    

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82. Gardening
    Metaphors
    

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83. Renovation
    Metaphors
    

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84. Conclusion
    

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85. Loving legacy code …
    

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86. can be rewarding
    

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87. Respect
    

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88. Thanks for listening!
    

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89. Keith Pitty
    @keithpitty
    

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