Bringing Old Legacy Apps To PHP 7 and Beyond - Midwest 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
   March 17th, 2017
   Sammy Kaye Powers
   @SammyK
   PHP 7 & Beyond
   

   View Slide

2. Codebase
   @SammyK #mwphp17 joind.in/talk/82979
   

   View Slide

3. View Slide

4. I’ll just rewrite
   this in
   ____________!
   @SammyK #mwphp17 joind.in/talk/82979
   

   View Slide

5. I’ll just rewrite
   this in
   ____________!
   @SammyK #mwphp17 joind.in/talk/82979
   

   View Slide

6. I’ll just rewrite
   this in
   ____________!
   Laravel
   @SammyK #mwphp17 joind.in/talk/82979
   

   View Slide

7. I’ll just rewrite
   this in
   ____________!
   @SammyK #mwphp17 joind.in/talk/82979
   

   View Slide

8. rewrite from
   scratch?
   Why not
   @SammyK #mwphp17 joind.in/talk/82979
   

   View Slide

9. Functionality
   Existing Codebase Fancy-pants rewrite
   

   View Slide

10. Functionality
    Existing Codebase Fancy-pants rewrite
    

    View Slide

11. Functionality
    Existing Codebase Fancy-pants rewrite
    

    View Slide

12. Functionality
    Existing Codebase Fancy-pants rewrite
    

    View Slide

13. Functionality
    Existing Codebase Fancy-pants rewrite
    

    View Slide

14. Refactoring
    Martin Fowler
    http://martinfowler.com/books/refactoring.html
    

    View Slide

15. “Legacy”
    /leɡəsē/
    • Requires an EOL version of PHP
    • No automated tests
    • Has outdated dependencies
    • No autoloading
    • No sign of “single responsibility”
    

    View Slide

16. View Slide

17. “Legacy”
    We’ll assume
    …means any code that
    can be improved
    (at least for this talk)
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

18. Expectations
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

19. elePHPant
    How to eat an
    

    View Slide

20. ZERO
    Step
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

21. Around
    Poke
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

22. 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)
    

    View Slide

23. Analysis
    Static
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

24. phploc
    

    View Slide

25. phploc
    

    View Slide

26. phpcpd
    

    View Slide

27. Consider the
    Stakeholders
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

28. Consider the Stakeholders
    I’ll need 80
    hours to
    refactor the
    user auth & ACL
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

29. Consider the Stakeholders
    • Most critical security holes
    • Most critical bugs
    • Most critical features
    • Use data from static analysis
    Make a plan
    

    View Slide

30. ONE
    Step
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

31. 5.(wat)
    @SammyK #mwphp17 joind.in/talk/82979
    Get it running on
    

    View Slide

32. Environment
    Get it running on your local
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

33. Kickass
    Development
    Environments
    with Docker
    David McKay
    Tomorrow @ 11 AM in Ballroom D
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

34. Git with an
    SCM
    

    View Slide

35. View Slide

36. Git
    Get with
    master
    original
    local-config
    

    View Slide

37. Fix all the errors
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

38. View Slide

39. TWO
    Step
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

40. 7.1
    @SammyK #mwphp17 joind.in/talk/82979
    Get it running on
    

    View Slide

41. 7.1
    ✓Performance
    increase
    PHP 7
    features
    ✓
    

    View Slide

42. 7.1
    

    View Slide

43. BC
    is totes amaze
    

    View Slide

44. PHP 7 enlightenment
    The path to
    7.1
    5.6
    

    View Slide

45. 7.1
    5.5
    PHP 7 enlightenment
    The path to
    

    View Slide

46. 7.1
    5.4
    PHP 7 enlightenment
    The path to
    

    View Slide

47. 7.1
    >= 5.3
    PHP 7 enlightenment
    The path to
    

    View Slide

48. THREE
    Step
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

49. Fix all the PHP 7 errors
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

50. PHP 7
    Quick tricks to refactor to
    (in order of ease)
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

51. PHP 7.0 “Gotchas”
    ASP and
    PHP<br/>tags removed<br/>@SammyK #mwphp17 joind.in/talk/82979<br/>

    View Slide

52. <% %>
    <%= %>
    <br/>
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

53. PHP 7.0 “Gotchas”
    removed
    $HTTP_RAW_POST_DATA
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

54. php://input
    instead read from
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

55. PHP 7.0 “Gotchas”
    PHP-4-style
    constructors
    deprecated
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

56. View Slide

57. View Slide

58. PHP 7.0 “Gotchas”
    Some
    functions
    got the ax
    ereg*
    functions
    

    View Slide

59. PHP 7.0 “Gotchas”
    “There’s a shim for that!”
    

    View Slide

60. PHP 7.0 “Gotchas”
    “There’s a shim for that!”
    ereg* functions
    bbrala/php7-ereg-shim
    (Björn Brala)
    

    View Slide

61. View Slide

62. PHP 7.0 “Gotchas”
    Another
    one bites
    the dust
    ext/mysql
    functions
    

    View Slide

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

    View Slide

64. Caveats though…
    

    View Slide

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

    View Slide

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

    View Slide

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

    View Slide

68. View Slide

69. PHP 7.0 “Gotchas”
    Uniform
    Variable Syntax
    Change in evaluating indirect expressions
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

70. View Slide

71. Variable variables
    string(5) "world"
    

    View Slide

72. View Slide

73. string(16) "PHP 5.x I see..."
    5.x
    

    View Slide

74. 7.x
    

    View Slide

75. View Slide

76. 5.x
    

    View Slide

77. 5.x
    

    View Slide

78. 5.x
    string(16) "PHP 5.x I see..."
    

    View Slide

79. 7.x
    

    View Slide

80. 7.x
    

    View Slide

81. 7.x
    

    View Slide

82. 7.x
    Notice: Array to string conversion in /
    foo.php on line 6
    Notice: Undefined variable: Array in /
    foo.php on line 6
    

    View Slide

83. Funky
    

    View Slide

84. View Slide

85. View Slide

86. 7.x
    5.x
    

    View Slide

87. FOUR
    Step
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

88. Code!
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

89. Tests
    TESTS
    Tests
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

90. PHPUnit?
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

91. Acceptance
    Tests
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

92. Codeception
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

93. Behavior-driven
    testing framework
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

94. Composer +
    Autoloading
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

95. @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

96. Feature
    (User Story)
    

    View Slide

97. Scenario
    

    View Slide

98. @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

99. Scenario
    @SammyK #mwphp17 joind.in/talk/82979
    

    View Slide

100. View Slide

101. FIVE
     Step
     “The Refactoring Loop”
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

102. refactorLoop:
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

103. Start
     small
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

104. View Slide

105. Make sure there’s a test
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

106. Refactor
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

107. Run your tests
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

108. goto refactorLoop;
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

109. lets you refactor like a
     BEAST
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

110. PHPUnit
     Don’t forget about
     

     View Slide

111. PHP 7.0
     Features
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

112. random_int()
     random_bytes()
     PHP 7.0 Features
     CSPRNG!!
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

113. JOURNEY
     MY
     CENTER
     TO
     THE
     OF
     #ShamelessPlug
     Tomorrow @ 10 am
     in Main Ballroom
     

     View Slide

114. PHP 7.0 Features
     Scalar Type
     Declarations
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

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

     int $age,

     bool $isGreat,

     float $income)

     { /* */ }
     

     View Slide

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

     int $age,

     bool $isGreat,

     float $income)

     { /* */ }
     

     View Slide

117. PHP 7.0 Features
     Return type
     declarations
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

118. PHP 7.0 Features
     Return type declarations
     /**

     * @return Collection

     */

     public function foo()

     {

     }
     

     View Slide

119. PHP 7.0 Features
     /**

     * @return Collection

     */

     public function foo()

     {

     }
     Return type declarations
     

     View Slide

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

     {

     }
     Return type declarations
     

     View Slide

121. PHP 7.0 Features
     Null coalesce
     operator
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

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

     View Slide

123. PHP 7.0 Features
     Insane speed
     improvements
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

124. PHP 7.1
     Considerations & Features
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

125. PHP 7.1 Considerations
     deprecated
     ext/mcrypt
     Soon to be...
     

     View Slide

126. rand() &
     mt_rand()
     changes
     PHP 7.1 Considerations
     

     View Slide

127. View Slide

128. Totes Samezies!
     

     View Slide

129. array_rand()
     Now with even distribution!
     PHP 7.1 Considerations
     

     View Slide

130. Void return
     types
     PHP 7.1 Features
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

131. public function foo(): void

     {

     }
     Void return types
     PHP 7.1 Features
     

     View Slide

132. Nullable
     types
     (kinda like union types for null)
     @SammyK #mwphp17 joind.in/talk/82979
     PHP 7.1 Features
     

     View Slide

133. Nullable types
     function foo(string $name)

     { /* */ }
     PHP 7.1 Features
     

     View Slide

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

     { /* */ }
     PHP 7.1 Features
     

     View Slide

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

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

     View Slide

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

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

     View Slide

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

     View Slide

138. Class constant
     visibility
     @SammyK #mwphp17 joind.in/talk/82979
     PHP 7.1 Features
     

     View Slide

139. Class constant visibility
     class Foo {

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

     View Slide

140. `iterable`
     pseudo-type
     @SammyK #mwphp17 joind.in/talk/82979
     PHP 7.1 Features
     

     View Slide

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

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

     View Slide

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

     View Slide

143. And
     beyond?
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

144. PHP 7.2
     Considering
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

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

     View Slide

146. PHP 7.2 considerations
     Argon2
     Password Hash
     password_*()
     (Could become new default in PHP 7.3/8.0)
     

     View Slide

147. Pending implementation…
     PHP 7.2
     

     View Slide

148. PHP 7.2 considerations
     sodium_*()
     

     View Slide

149. PHP 7.2 considerations
     Trailing Comma
     

     View Slide

150. 7.2 Deprecations
     (Will be removed by PHP 8.0)
     

     View Slide

151. Some tools
     I like
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

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

     View Slide

153. Some tools I like
     pimple/pimple
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

154. Some tools I like
     monolog/monolog
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

155. Some tools I like
     nikic/fast-route
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

156. Some tools I like
     illuminate/database
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

157. Some tools I like
     symfony/console
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

158. Create a PHP
     application without a
     framework
     https://github.com/PatrickLouys/no-framework-tutorial
     Patrick Louys
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

159. Big-picture
     Refactoring
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

160. Constant refactoring
     is the key to managing
     legacy
     codebases
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

161. Constant refactoring
     is the key to managing
     legacy
     codebases
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

162. Resources
     013: TDD & BDD In PHP
     055: Acceptance
     Testing with Behat
     017: Modernizing Legacy
     Codebases in PHP
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

163. Modernizing Legacy
     Applications in PHP
     https://leanpub.com/mlaphp
     Paul M. Jones
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

164. Refactoring
     Martin Fowler
     http://martinfowler.com/books/refactoring.html
     @SammyK #mwphp17 joind.in/talk/82979
     

     View Slide

165. Takk!
     (thanks)
     @SammyK
     SammyK.me
     Host of @PHPRoundtable
     @ChiPHPUG
     West Coast Swing
     Hire me! :)
     /talk/82979
     

     View Slide