Bringing Old Legacy Apps To PHP 7 and Beyond - ZendCon 2016

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 or a web app written years ago on a now-defunct web framework. The initial temptation might be, "I'll just rewrite all this in x framework." But hold on my framework friend, a rewrite is costly and is rarely the correct answer. We'll discuss strategies to give that legacy codebase a complete makeover in PHP 7 with incremental changes that keep the business running while improving security, stability, and maintainability of the codebase.

Transcript

1. Bringing Old Legacy Apps To October 19th, 2016 Sammy Kaye Powers @SammyK PHP 7 & Beyond
2. Codebase @SammyK #zendcon2016 joind.in/talk/6d127
4. I’ll just rewrite this in ____________! @SammyK #zendcon2016 joind.in/talk/6d127
5. I’ll just rewrite this in ____________! @SammyK #zendcon2016 joind.in/talk/6d127
6. I’ll just rewrite this in ____________! Laravel @SammyK #zendcon2016 joind.in/talk/6d127
7. I’ll just rewrite this in ____________! @SammyK #zendcon2016 joind.in/talk/6d127
8. rewrite from scratch? Why not @SammyK #zendcon2016 joind.in/talk/6d127
9. Functionality Existing Codebase Fancy-pants rewrite
10. Functionality Existing Codebase Fancy-pants rewrite
11. Functionality Existing Codebase Fancy-pants rewrite
12. Functionality Existing Codebase Fancy-pants rewrite
13. Functionality Existing Codebase Fancy-pants rewrite
14. Refactoring Martin Fowler http://martinfowler.com/books/refactoring.html
15. “Legacy” /leɡəsē/ • Requires an EOL version of PHP • No automated tests • Has outdated dependencies • No autoloading • No sign of “single responsibility”
17. “Legacy” We’ll assume …means any code that can be improved @SammyK #zendcon2016 joind.in/talk/6d127 (at least for this talk)
18. Expectations @SammyK #zendcon2016 joind.in/talk/6d127
19. elePHPant How to eat an
20. ZERO Step @SammyK #zendcon2016 joind.in/talk/6d127
21. Around Poke @SammyK #zendcon2016 joind.in/talk/6d127
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)
23. Analysis Static @SammyK #zendcon2016 joind.in/talk/6d127
24. phploc
25. phploc
26. phpcpd
27. Consider the Stakeholders @SammyK #zendcon2016 joind.in/talk/6d127
28. Consider the Stakeholders I’ll need 80 hours to refactor the user auth & ACL @SammyK #zendcon2016 joind.in/talk/6d127
29. Consider the Stakeholders • Most critical security holes • Most critical bugs • Most critical features • Use data from static analysis Make a plan
30. ONE Step @SammyK #zendcon2016 joind.in/talk/6d127
31. Environment Get it running on your local @SammyK #zendcon2016 joind.in/talk/6d127
32. From Docker to production Chris Tankersley @SammyK #zendcon2016 joind.in/talk/6d127 Today @ 5:15PM in Artist 3
33. Git Get with master original local-config
34. 5.(wat) @SammyK #zendcon2016 joind.in/talk/6d127
35. Fix all the errors @SammyK #zendcon2016 joind.in/talk/6d127
37. TWO Step @SammyK #zendcon2016 joind.in/talk/6d127
38. 7.0 @SammyK #zendcon2016 joind.in/talk/6d127
39. 7.0 ✓Performance increase PHP 7 features ✓
40. 7.0
41. BC is totes amaze
42. PHP 7.0 enlightenment The path to 7.0 5.6
43. PHP 7.0 enlightenment The path to 7.0 5.5
44. PHP 7.0 enlightenment The path to 7.0 5.4
45. PHP 7.0 enlightenment The path to 7.0 >= 5.3
46. THREE Step @SammyK #zendcon2016 joind.in/talk/6d127
47. Fix all the PHP 7 errors @SammyK #zendcon2016 joind.in/talk/6d127
48. PHP 7.0 Quick tricks to refactor to (in order of ease) @SammyK #zendcon2016 joind.in/talk/6d127
49. PHP 7.0 “Gotchas” ASP and script PHP tags removed <% %> <%= %> <script language="php"></script>
50. PHP 7.0 “Gotchas” removed php://input $HTTP_RAW_POST_DATA instead read from $HTTP_RAW_POST_DATA = file_get_contents('php://input');
51. PHP 7.0 “Gotchas” PHP-4-style constructors deprecated class foo { function foo() {} }
52. PHP 7.0 “Gotchas” PHP-4-style constructors deprecated class foo { function __construct() {} }
53. PHP 7.0 “Gotchas” Some functions got the ax ereg* functions
54. PHP 7.0 “Gotchas” “There’s a shim for that!”
55. PHP 7.0 “Gotchas” “There’s a shim for that!” ereg* functions bbrala/php7-ereg-shim eregi($pattern, $sub, &$match) preg_match('/'.$pattern.'/i', $sub, $match)
56. PHP 7.0 “Gotchas” Another one bites the dust ext/mysql functions
57. PHP 7.0 “Gotchas” “There’s a shim for that!” ext/mysql functions dshafik/php7-mysql-shim
58. PHP 7.0 “Gotchas” Caveats though… ext/mysql functions dshafik/php7-mysql-shim $con = mysql_connect(…); $connected = is_resource($con);
59. PHP 7.0 “Gotchas” Another bird with the PHP 7.0 stone ext/mssql functions instead use sqlsrv_*(), odbc_*(), PDO
60. PHP 7.0 “Gotchas” A few others for the chopping block Some ext/mcrypt functions, et. al.
61. PHP 7.0 “Gotchas” Scalar Type Declarations New reserved keywords: string, int, bool, float
63. PHP 7.0 “Gotchas” Uniform Variable Syntax Change in evaluating indirect expressions @SammyK #zendcon2016 joind.in/talk/6d127
64. PHP 7.0 “Gotchas” Uniform Variable Syntax $$foo['bar']['baz']
65. PHP 7.0 “Gotchas” Uniform Variable Syntax $foo = ['bar' => ['baz' => ‘apple']]; $apple = 'PHP 5.x I see...'; var_dump($$foo['bar']['baz']); string(16) "PHP 5.x I see..." 5.x
66. PHP 7.0 “Gotchas” Uniform Variable Syntax Notice: Array to string conversion in / foo.php on line 6 Notice: Undefined variable: Array in / foo.php on line 6 7.x
67. PHP 7.0 “Gotchas” Uniform Variable Syntax $$foo['bar']['baz'] 5.x
68. PHP 7.0 “Gotchas” Uniform Variable Syntax $$foo['bar']['baz'] 5.x
69. PHP 7.0 “Gotchas” Uniform Variable Syntax ${'apple'} 5.x
70. PHP 7.0 “Gotchas” Uniform Variable Syntax $apple 5.x string(16) "PHP 5.x I see..."
71. PHP 7.0 “Gotchas” Uniform Variable Syntax $$foo['bar']['baz'] 7.x
72. PHP 7.0 “Gotchas” Uniform Variable Syntax $$foo['bar']['baz'] 7.x
73. PHP 7.0 “Gotchas” Uniform Variable Syntax ${['bar' => ['baz' => ‘apple']} [‘bar’]['baz'] 7.x
74. PHP 7.0 “Gotchas” Uniform Variable Syntax ${‘Array’}[‘bar’]['baz'] 7.x
75. PHP 7.0 “Gotchas” Uniform Variable Syntax $$foo['bar']['baz'] 7.x
76. PHP 7.0 “Gotchas” Uniform Variable Syntax ${$foo[‘bar’]['baz']} 7.x
77. PHP 7.0 “Gotchas” $$foo['bar']['baz'] ${$foo['bar']['baz']} ($$foo)['bar']['baz'] 5.x 7.x Uniform Variable Syntax
78. FOUR Step @SammyK #zendcon2016 joind.in/talk/6d127
79. Code! @SammyK #zendcon2016 joind.in/talk/6d127
80. Tests TESTS Tests @SammyK #zendcon2016 joind.in/talk/6d127
81. PHPUnit? @SammyK #zendcon2016 joind.in/talk/6d127
82. Acceptance Tests @SammyK #zendcon2016 joind.in/talk/6d127
83. Codeception @SammyK #zendcon2016 joind.in/talk/6d127
84. Behavior-driven testing framework @SammyK #zendcon2016 joind.in/talk/6d127
85. Composer + Autoloading @SammyK #zendcon2016 joind.in/talk/6d127
86. @SammyK #zendcon2016 joind.in/talk/6d127
87. Feature (User Story)
88. Scenario
89. @SammyK #zendcon2016 joind.in/talk/6d127
90. Scenario @SammyK #zendcon2016 joind.in/talk/6d127
92. FIVE Step “The Refactoring Loop” @SammyK #zendcon2016 joind.in/talk/6d127
93. refactorLoop: @SammyK #zendcon2016 joind.in/talk/6d127
94. Start small @SammyK #zendcon2016 joind.in/talk/6d127
96. Make sure there’s a test @SammyK #zendcon2016 joind.in/talk/6d127
97. @SammyK #zendcon2016 joind.in/talk/6d127 Refactor
98. Run your tests @SammyK #zendcon2016 joind.in/talk/6d127
99. goto refactorLoop; @SammyK #zendcon2016 joind.in/talk/6d127
100. lets you refactor like a BEAST @SammyK #zendcon2016 joind.in/talk/6d127
101. PHPUnit Don’t forget about
102. PHP 7.0 Features @SammyK #zendcon2016 joind.in/talk/6d127
103. random_int() random_bytes() PHP 7.0 Features CSPRNG!! @SammyK #zendcon2016 joind.in/talk/6d127
104. JOURNEY MY CENTER TO THE OF #ShamelessPlug Tomorrow @ 11:30am in Festival 2
105. PHP 7.0 Features Scalar Type Declarations @SammyK #zendcon2016 joind.in/talk/6d127
106. PHP 7.0 Features Scalar Type Declarations function foo(string $name,
 int $age,
 bool $isGreat,
 float $income)
 { /* */ }
107. PHP 7.0 Features Scalar Type Declarations function foo(string $name,
 int $age,
 bool $isGreat,
 float $income)
 { /* */ }
108. 99.99999999999942 I got problems but float $income NEVER USE FLOATS FOR MONEY!
109. PHP 7.0 Features Return type declarations @SammyK #zendcon2016 joind.in/talk/6d127
110. PHP 7.0 Features Return type declarations /**
 * @return Collection
 */
 public function foo()
 {
 }
111. PHP 7.0 Features /**
 * @return Collection
 */
 public function foo()
 {
 } Return type declarations
112. PHP 7.0 Features public function foo(): Collection
 {
 } Return type declarations
113. PHP 7.0 Features Null coalesce operator @SammyK #zendcon2016 joind.in/talk/6d127
114. PHP 7.0 Features $bar = isset($_GET[‘foo’]) ? $_GET[‘foo’] : null; Null coalesce operator $bar = $_GET[‘foo’] ?? null;
115. PHP 7.0 Features Insane speed improvements @SammyK #zendcon2016 joind.in/talk/6d127
116. And beyond? @SammyK #zendcon2016 joind.in/talk/6d127
117. PHP 7.1 Considering RC3 @SammyK #zendcon2016 joind.in/talk/6d127
118. PHP 7.1 considerations deprecated ext/mcrypt Soon to be...
119. Void return types PHP 7.1 considerations @SammyK #zendcon2016 joind.in/talk/6d127
120. public function foo(): void
 {
 } Void return types PHP 7.1 considerations
121. Nullable types PHP 7.1 considerations @SammyK #zendcon2016 joind.in/talk/6d127 (kinda like union types for null)
122. Nullable types function foo(string $name)
 { /* */ } PHP 7.1 considerations
123. Nullable types function foo(?string $name)
 { /* */ } PHP 7.1 considerations
124. Nullable types function foo(string $name = null)
 { /* */ } foo(); PHP 7.1 considerations
125. Nullable types foo(); function foo(?string $name)
 { /* */ } foo(null); PHP 7.1 considerations
126. Nullable types function foo(): ?string { return null; } PHP 7.1 considerations
127. Class constant visibility PHP 7.1 considerations @SammyK #zendcon2016 joind.in/talk/6d127
128. Class constant visibility class Foo {
 public const FOO = 0; protected const BAR = 1; private const BAZ = 2; } PHP 7.1 considerations
129. `iterable` pseudo-type PHP 7.1 considerations @SammyK #zendcon2016 joind.in/talk/6d127
130. `iterable` pseudo-type function foo(iterable $a)
 { /* */ } PHP 7.1 considerations $b = []; foo($b); class C implements Iterator {} $b = new C; foo($b);
131. `iterable` pseudo-type PHP 7.1 considerations class D implements IteratorAggregate {} foo(new D); Traversable Or instance of
132. Some tools I like @SammyK #zendcon2016 joind.in/talk/6d127
133. vlucas/phpdotenv .env No peeking! No peeking!
134. Some tools I like pimple/pimple @SammyK #zendcon2016 joind.in/talk/6d127
135. Some tools I like monolog/monolog @SammyK #zendcon2016 joind.in/talk/6d127
136. Some tools I like nikic/fast-route @SammyK #zendcon2016 joind.in/talk/6d127
137. Some tools I like illuminate/database @SammyK #zendcon2016 joind.in/talk/6d127
138. Some tools I like symfony/console @SammyK #zendcon2016 joind.in/talk/6d127
139. Create a PHP application without a framework https://github.com/PatrickLouys/no-framework-tutorial Patrick Louys @SammyK #zendcon2016 joind.in/talk/6d127
140. Big-picture Refactoring @SammyK #zendcon2016 joind.in/talk/6d127
141. Constant refactoring is the key to managing legacy codebases @SammyK #zendcon2016 joind.in/talk/6d127
142. Constant refactoring is the key to managing legacy codebases @SammyK #zendcon2016 joind.in/talk/6d127
143. Resources 013: TDD & BDD In PHP Soon: Acceptance Testing with Behat 017: Modernizing Legacy Codebases in PHP November 3rd @ 12:00PM CDT
144. Modernizing Legacy Applications in PHP https://leanpub.com/mlaphp Paul M. Jones @SammyK #zendcon2016 joind.in/talk/6d127
145. Refactoring Martin Fowler http://martinfowler.com/books/refactoring.html @SammyK #zendcon2016 joind.in/talk/6d127
146. Takk! (thanks) @SammyK SammyK.me Host of @PHPRoundtable @ChiPHPUG West Coast Swing Hire me! :) /talk/6d127