Bringing Old Legacy Apps To PHP 7 and Beyond - PNWPHP 2017

Talk given at Pacific Northwest PHP 2017

Most developers don't get the luxury of working on a greenfield project using a web framework of their choice. Often times we find ourselves inheriting a legacy codebase written years ago for an end-of-life version of PHP and a now-defunct web framework. The initial temptation might be, "I'll just rewrite all this on x framework". But hold on there my framework friend, a rewrite is costly and is rarely the correct answer. We'll discuss some common pitfalls when getting a legacy codebase ready for PHP 7 and what we can do to make the upgrade path as painless as possible. These incremental changes will keep the business running while improving security, stability and maintainability of the codebase.

Transcript

1. Bringing Old Legacy Apps To
   September 9th, 2017
   Sammy Kaye Powers
   @SammyK
   PHP 7 & Beyond
   

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2. joind.in/talk/228f1
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   Slides
   Get the
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3. joind.in/talk/228f1
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   Upgrade Path
   7.1
   Less about
   More about
   Refactoring
   Strategies
   to
   

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   Codebase
   

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   I’ll just rewrite
   this in
   ____________!
   

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7. joind.in/talk/228f1
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   I’ll just rewrite
   this in
   ____________!
   

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8. joind.in/talk/228f1
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   I’ll just rewrite
   this in
   ____________!
   Laravel
   

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9. joind.in/talk/228f1
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   I’ll just rewrite
   this in
   ____________!
   

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10. joind.in/talk/228f1
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    rewrite from
    scratch?
    Why not
    

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11. joind.in/talk/228f1
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    Functionality
    Existing Codebase Fancy-pants rewrite
    

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12. joind.in/talk/228f1
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    Functionality
    Existing Codebase Fancy-pants rewrite
    

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13. joind.in/talk/228f1
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    Functionality
    Existing Codebase Fancy-pants rewrite
    

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14. joind.in/talk/228f1
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    Functionality
    Existing Codebase Fancy-pants rewrite
    

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15. joind.in/talk/228f1
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    Functionality
    Existing Codebase Fancy-pants rewrite
    

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16. joind.in/talk/228f1
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    Refactoring
    Martin Fowler
    http://martinfowler.com/books/refactoring.html
    

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17. joind.in/talk/228f1
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    “Legacy”
    /leɡəsē/
    • Requires an EOL version of PHP
    • No automated tests
    • Has outdated dependencies
    • No autoloading
    • No sign of “single responsibility”
    

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19. joind.in/talk/228f1
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    “Legacy”
    We’ll assume
    …means any code that is
    running on PHP 5.x
    (at least for this talk)
    

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    Expectations
    

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21. joind.in/talk/228f1
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    elePHPant
    How to eat an
    

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    ZERO
    Step
    

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23. joind.in/talk/228f1
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    Around
    Poke
    

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24. joind.in/talk/228f1
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    Around
    Poke
    • Composer &/or autoloading?
    • Documentation? (Look for hidden docs!)
    • Framework/Dependencies? (How out-dated?)
    • How is database layer implemented?
    • How is config handled?
    • How are front-end assets handled?
    • Are there tests?
    • Production env (PHP version)
    

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25. joind.in/talk/228f1
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    Analysis
    Static
    

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26. phploc
    

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27. phploc
    

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28. phpcpd
    

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29. joind.in/talk/228f1
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    Consider the
    Stakeholders
    

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30. joind.in/talk/228f1
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    Consider the Stakeholders
    I’ll need 80
    hours to
    refactor the
    user auth & ACL
    

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31. joind.in/talk/228f1
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    Consider the Stakeholders
    • Most critical security holes
    • Most critical bugs
    • Most critical features
    • Use data from static analysis
    Make a plan
    

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32. joind.in/talk/228f1
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    ONE
    Step
    

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33. joind.in/talk/228f1
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    5.(wat)
    Get it running on
    

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34. Environment
    Get it running on your local
    

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35. joind.in/talk/228f1
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    Git with an
    SCM
    

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36. joind.in/talk/228f1
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37. joind.in/talk/228f1
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    Git
    Get with
    master
    original
    local-config
    

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38. joind.in/talk/228f1
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    Fix all the errors
    

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40. joind.in/talk/228f1
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    TWO
    Step
    

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41. joind.in/talk/228f1
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    7.1
    Get it running on
    

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42. joind.in/talk/228f1
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    PHP 7.0
    Is almost
    2 years old!
    

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43. joind.in/talk/228f1
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    2
    

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44. joind.in/talk/228f1
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    years
    

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45. joind.in/talk/228f1
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    old!
    

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46. joind.in/talk/228f1
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    OLD
    

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47. joind.in/talk/228f1
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    http://php.net/supported-versions.php
    > 3 months
    Active support (bug fixes) for PHP 7.0 ends
    

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48. joind.in/talk/228f1
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    OLD
    PHP 7.0 is
    

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49. 7.1
    ✓Performance
    increase
    PHP 7
    features
    ✓
    

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50. 7.1
    

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51. BC
    is totes amaze
    

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52. joind.in/talk/228f1
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    PHP 7 enlightenment
    The path to
    7.1
    5.6
    

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53. joind.in/talk/228f1
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    7.1
    5.5
    PHP 7 enlightenment
    The path to
    

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54. joind.in/talk/228f1
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    7.1
    5.4
    PHP 7 enlightenment
    The path to
    

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55. joind.in/talk/228f1
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    7.1
    <= 5.3
    PHP 7 enlightenment
    The path to
    

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56. joind.in/talk/228f1
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    THREE
    Step
    

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57. joind.in/talk/228f1
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    Fix all the PHP 7 errors
    

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58. joind.in/talk/228f1
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    PHP 7
    Quick tricks to refactor to
    (in order of ease)
    

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59. joind.in/talk/228f1
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    PHP 7.0 “Gotchas”
    ASP and
    PHP<br/>tags removed<br/>

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60. <% %>
    <%= %>
    <br/>
    

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61. joind.in/talk/228f1
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    PHP 7.0 “Gotchas”
    removed
    $HTTP_RAW_POST_DATA
    

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62. joind.in/talk/228f1
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    php://input
    instead read from
    

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63. joind.in/talk/228f1
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    PHP 7.0 “Gotchas”
    PHP-4-style
    constructors
    deprecated
    

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65. joind.in/talk/228f1
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66. PHP 7.0 “Gotchas”
    Some
    functions
    got the ax
    ereg*
    functions
    

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67. joind.in/talk/228f1
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    PHP 7.0 “Gotchas”
    “There’s a shim for that!”
    

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68. joind.in/talk/228f1
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    PHP 7.0 “Gotchas”
    “There’s a shim for that!”
    ereg* functions
    bbrala/php7-ereg-shim
    (Björn Brala)
    

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69. joind.in/talk/228f1
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70. PHP 7.0 “Gotchas”
    Another
    one bites
    the dust
    ext/mysql
    functions
    

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71. PHP 7.0 “Gotchas”
    “There’s a shim for that!”
    ext/mysql functions
    dshafik/php7-mysql-shim
    (Davey Shafik)
    

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72. joind.in/talk/228f1
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    Caveats though…
    

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73. PHP 7.0 “Gotchas”
    Another bird
    with the
    PHP 7.0 stone
    ext/mssql
    functions
    instead use
    sqlsrv_*(), odbc_*(), PDO
    

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74. PHP 7.0 “Gotchas”
    A few others
    for the
    chopping
    block
    Some
    ext/mcrypt
    functions,
    et. al.
    

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75. PHP 7.0 “Gotchas”
    Scalar Type
    Declarations
    New reserved keywords:
    string, int, bool, float
    

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    PHP 7.0 “Gotchas”
    Uniform
    Variable Syntax
    Change in evaluating indirect expressions
    

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78. joind.in/talk/228f1
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79. Variable variables
    string(5) "world"
    

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80. joind.in/talk/228f1
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81. string(16) "PHP 5.x I see..."
    5.x
    

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82. 7.x
    

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83. joind.in/talk/228f1
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84. joind.in/talk/228f1
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    5.x
    

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85. joind.in/talk/228f1
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    5.x
    

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86. joind.in/talk/228f1
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    5.x
    string(16) "PHP 5.x I see..."
    

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87. joind.in/talk/228f1
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    7.x
    

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88. joind.in/talk/228f1
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    7.x
    

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89. joind.in/talk/228f1
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    7.x
    

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90. joind.in/talk/228f1
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    7.x
    Notice: Array to string conversion in /
    foo.php on line 6
    Notice: Undefined variable: Array in /
    foo.php on line 6
    

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91. joind.in/talk/228f1
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    Funky
    

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92. joind.in/talk/228f1
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93. View Slide

94. joind.in/talk/228f1
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    7.x
    5.x
    

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95. joind.in/talk/228f1
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    FOUR
    Step
    

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96. joind.in/talk/228f1
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    Code!
    

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97. joind.in/talk/228f1
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    Tests
    TESTS
    Tests
    

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98. joind.in/talk/228f1
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    PHPUnit?
    

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99. joind.in/talk/228f1
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    Acceptance
    Tests
    

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100. joind.in/talk/228f1
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     Codeception
     

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101. joind.in/talk/228f1
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     Behavior-driven
     testing framework
     

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102. joind.in/talk/228f1
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     Composer +
     Autoloading
     

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103. joind.in/talk/228f1
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104. Feature
     (User Story)
     

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105. joind.in/talk/228f1
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     Scenario
     

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106. joind.in/talk/228f1
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107. joind.in/talk/228f1
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     Scenario
     

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109. joind.in/talk/228f1
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     FIVE
     Step
     “The Refactoring Loop”
     

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110. joind.in/talk/228f1
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     refactorLoop:
     

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111. joind.in/talk/228f1
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     Start
     small
     

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112. View Slide

113. joind.in/talk/228f1
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     Make sure there’s a test
     

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114. joind.in/talk/228f1
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     Refactor
     

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115. joind.in/talk/228f1
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     Run your tests
     

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116. joind.in/talk/228f1
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     goto refactorLoop;
     

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117. joind.in/talk/228f1
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     lets you refactor like a
     BEAST
     

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118. PHPUnit
     Don’t forget about
     

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119. joind.in/talk/228f1
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     End-to-end
     is great!
     Except when…
     

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120. joind.in/talk/228f1
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     It’s
     Not
     

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121. joind.in/talk/228f1
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     PHP 7.0
     Features
     

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122. joind.in/talk/228f1
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     random_int()
     random_bytes()
     PHP 7.0 Features
     CSPRNG!!
     

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123. joind.in/talk/228f1
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     PHP 7.0 Features
     Scalar Type
     Declarations
     

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124. PHP 7.0 Features
     Scalar Type Declarations
     function foo(string $name,

     int $age,

     bool $isGreat,

     float $income)

     { /* */ }
     

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125. PHP 7.0 Features
     Scalar Type Declarations
     function foo(string $name,

     int $age,

     bool $isGreat,

     float $income)

     { /* */ }
     

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126. joind.in/talk/228f1
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     PHP 7.0 Features
     Return type
     declarations
     

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127. PHP 7.0 Features
     Return type declarations
     /**

     * @return Collection

     */

     public function foo()

     {

     }
     

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128. PHP 7.0 Features
     /**

     * @return Collection

     */

     public function foo()

     {

     }
     Return type declarations
     

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129. PHP 7.0 Features
     public function foo(): Collection

     {

     }
     Return type declarations
     

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130. joind.in/talk/228f1
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     PHP 7.0 Features
     Null coalesce
     operator
     

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131. PHP 7.0 Features
     $bar = isset($_GET[‘foo’]) ?
     $_GET[‘foo’] : null;
     Null coalesce operator
     $bar = $_GET[‘foo’] ?? null;
     

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132. joind.in/talk/228f1
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     PHP 7.0 Features
     Insane speed
     improvements
     

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133. joind.in/talk/228f1
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     PHP 7.1
     Considerations & Features
     

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134. joind.in/talk/228f1
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     PHP 7.1 Considerations
     deprecated
     ext/mcrypt
     Soon to be...
     

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135. joind.in/talk/228f1
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     rand() &
     mt_rand()
     changes
     PHP 7.1 Considerations
     

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136. joind.in/talk/228f1
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137. joind.in/talk/228f1
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     Totes Samezies!
     

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138. joind.in/talk/228f1
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     array_rand()
     Now with even distribution!
     PHP 7.1 Considerations
     

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139. joind.in/talk/228f1
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     Void return
     types
     PHP 7.1 Features
     

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140. public function foo(): void

     {

     }
     Void return types
     PHP 7.1 Features
     

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141. joind.in/talk/228f1
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     Nullable
     types
     (kinda like union types for null)
     PHP 7.1 Features
     

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142. Nullable types
     function foo(string $name)

     { /* */ }
     PHP 7.1 Features
     

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143. Nullable types
     function foo(?string $name)

     { /* */ }
     PHP 7.1 Features
     

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144. Nullable types
     function foo(string $name = null)

     { /* */ }
     foo();
     PHP 7.1 Features
     

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145. Nullable types
     foo();
     function foo(?string $name)

     { /* */ }
     foo(null);
     PHP 7.1 Features
     

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146. Nullable types
     function foo(): ?string {
     return null;
     }
     PHP 7.1 Features
     

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147. joind.in/talk/228f1
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     Class constant
     visibility
     PHP 7.1 Features
     

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148. Class constant visibility
     class Foo {

     public const FOO = 0;
     protected const BAR = 1;
     private const BAZ = 2;
     }
     PHP 7.1 Features
     

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149. joind.in/talk/228f1
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     `iterable`
     pseudo-type
     PHP 7.1 Features
     

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150. `iterable` pseudo-type
     function foo(iterable $a)

     { /* */ }
     $b = [];
     foo($b);
     class C implements Iterator {}
     $b = new C;
     foo($b);
     PHP 7.1 Features
     

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151. `iterable` pseudo-type
     class D implements IteratorAggregate {}
     foo(new D);
     Traversable
     Or instance of
     PHP 7.1 Features
     

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152. joind.in/talk/228f1
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     And
     beyond?
     

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153. joind.in/talk/228f1
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     PHP 7.2
     Considering
     

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154. PHP 7.2 considerations
     re(moved)
     ext/mcrypt
     

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155. joind.in/talk/228f1
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     PHP 7.2 considerations
     Argon2
     Password Hash
     password_*()
     (Could become new default in PHP 7.3/8.0)
     

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156. joind.in/talk/228f1
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     PHP 7.2 considerations
     sodium_*()
     

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157. joind.in/talk/228f1
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     PHP 7.2 considerations
     Trailing Comma
     

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158. joind.in/talk/228f1
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     PHP 7.2 considerations
     Undefined
     Constants
     

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159. joind.in/talk/228f1
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     PHP 7.2 considerations
     

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160. joind.in/talk/228f1
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     PHP 7.2 considerations
     

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161. joind.in/talk/228f1
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     PHP 7.2 considerations
     Type Annotation
     object
     

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162. joind.in/talk/228f1
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     PHP 7.2 considerations
     

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163. joind.in/talk/228f1
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     7.2 Deprecations
     (Will be removed by PHP 8.0)
     

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164. joind.in/talk/228f1
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     Some tools
     I like
     

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165. vlucas/phpdotenv
     .env
     No peeking!
     No peeking!
     

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166. vlucas/phpdotenv
     NotSecure :(
     

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167. Env vars aren’t designed for secrets
     (shared with child processes, etc)
     Error messages can contain dump
     of env vars (filp/whoops)
     

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168. joind.in/talk/228f1
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     Some tools I like
     pimple/pimple
     

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169. joind.in/talk/228f1
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     Some tools I like
     monolog/monolog
     

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170. joind.in/talk/228f1
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     Some tools I like
     nikic/fast-route
     

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171. joind.in/talk/228f1
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     Some tools I like
     illuminate/database
     

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172. joind.in/talk/228f1
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     Some tools I like
     symfony/console
     

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173. joind.in/talk/228f1
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     Create a PHP
     application without a
     framework
     https://github.com/PatrickLouys/no-framework-tutorial
     Patrick Louys
     

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174. joind.in/talk/228f1
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     Big-picture
     Refactoring
     

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175. joind.in/talk/228f1
     @SammyK #pnwphp
     Constant refactoring
     is the key to managing
     legacy
     codebases
     

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176. joind.in/talk/228f1
     @SammyK #pnwphp
     Constant refactoring
     is the key to managing
     legacy
     codebases
     

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177. joind.in/talk/228f1
     @SammyK #pnwphp
     Resources
     013: TDD & BDD In PHP
     055: Acceptance
     Testing with Behat
     017: Modernizing Legacy
     Codebases in PHP
     

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178. joind.in/talk/228f1
     @SammyK #pnwphp
     Modernizing Legacy
     Applications in PHP
     https://leanpub.com/mlaphp
     Paul M. Jones
     

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179. joind.in/talk/228f1
     @SammyK #pnwphp
     Refactoring
     Martin Fowler
     http://martinfowler.com/books/refactoring.html
     

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180. I have
     stickers!
     Takk!
     (thanks)
     @SammyK
     SammyK.me
     Host of @PHPRoundtable
     @ChiPHPUG
     West Coast Swing
     /talk/228f1
     

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