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
2. Codebase @SammyK #mwphp17 joind.in/talk/82979
4. I’ll just rewrite this in ____________! @SammyK #mwphp17 joind.in/talk/82979
5. I’ll just rewrite this in ____________! @SammyK #mwphp17 joind.in/talk/82979
6. I’ll just rewrite this in ____________! Laravel @SammyK #mwphp17 joind.in/talk/82979
7. I’ll just rewrite this in ____________! @SammyK #mwphp17 joind.in/talk/82979
8. rewrite from scratch? Why not @SammyK #mwphp17 joind.in/talk/82979
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 “Legacy” /leɡəsē/ • Requires an EOL version of PHP • No automated tests • Has outdated dependencies • No autoloading • No sign of “single responsibility”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 (at least for this talk) @SammyK #mwphp17 joind.in/talk/82979
18. Expectations @SammyK #mwphp17 joind.in/talk/82979
19. elePHPant How to eat an
20. ZERO Step @SammyK #mwphp17 joind.in/talk/82979
21. Around Poke @SammyK #mwphp17 joind.in/talk/82979
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 #mwphp17 joind.in/talk/82979
24. phploc
25. phploc
26. phpcpd
27. Consider the Stakeholders @SammyK #mwphp17 joind.in/talk/82979
28. Consider the Stakeholders I’ll need 80 hours to refactor the user auth & ACL @SammyK #mwphp17 joind.in/talk/82979
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 #mwphp17 joind.in/talk/82979
31. 5.(wat) @SammyK #mwphp17 joind.in/talk/82979 Get it running on
32. Environment Get it running on your local @SammyK #mwphp17 joind.in/talk/82979
33. Kickass Development Environments with Docker David McKay Tomorrow @ 11 AM in Ballroom D @SammyK #mwphp17 joind.in/talk/82979
34. Git with an SCM
36. Git Get with master original local-config
37. Fix all the errors @SammyK #mwphp17 joind.in/talk/82979
39. TWO Step @SammyK #mwphp17 joind.in/talk/82979
40. 7.1 @SammyK #mwphp17 joind.in/talk/82979 Get it running on
41. 7.1 ✓Performance increase PHP 7 features ✓
42. 7.1
43. BC is totes amaze
44. PHP 7 enlightenment The path to 7.1 5.6
45. 7.1 5.5 PHP 7 enlightenment The path to
46. 7.1 5.4 PHP 7 enlightenment The path to
47. 7.1 >= 5.3 PHP 7 enlightenment The path to
48. THREE Step @SammyK #mwphp17 joind.in/talk/82979
49. Fix all the PHP 7 errors @SammyK #mwphp17 joind.in/talk/82979
50. PHP 7 Quick tricks to refactor to (in order of ease) @SammyK #mwphp17 joind.in/talk/82979
51. PHP 7.0 “Gotchas” ASP and <script> PHP tags removed @SammyK #mwphp17 joind.in/talk/82979
52. <% %> <%= %> <script language=“php"> </script> @SammyK #mwphp17 joind.in/talk/82979
53. PHP 7.0 “Gotchas” removed $HTTP_RAW_POST_DATA @SammyK #mwphp17 joind.in/talk/82979
54. php://input instead read from @SammyK #mwphp17 joind.in/talk/82979
55. PHP 7.0 “Gotchas” PHP-4-style constructors deprecated @SammyK #mwphp17 joind.in/talk/82979
58. PHP 7.0 “Gotchas” Some functions got the ax ereg* functions
59. PHP 7.0 “Gotchas” “There’s a shim for that!”
60. PHP 7.0 “Gotchas” “There’s a shim for that!” ereg* functions bbrala/php7-ereg-shim (Björn Brala)
62. PHP 7.0 “Gotchas” Another one bites the dust ext/mysql functions
63. PHP 7.0 “Gotchas” “There’s a shim for that!” ext/mysql functions dshafik/php7-mysql-shim (Davey Shafik)
64. Caveats though…
65. PHP 7.0 “Gotchas” Another bird with the PHP 7.0 stone ext/mssql functions instead use sqlsrv_*(), odbc_*(), PDO
66. PHP 7.0 “Gotchas” A few others for the chopping block Some ext/mcrypt functions, et. al.
67. PHP 7.0 “Gotchas” Scalar Type Declarations New reserved keywords: string, int, bool, float
69. PHP 7.0 “Gotchas” Uniform Variable Syntax Change in evaluating indirect expressions @SammyK #mwphp17 joind.in/talk/82979
71. Variable variables string(5) "world"
73. string(16) "PHP 5.x I see..." 5.x
74. 7.x
76. 5.x
77. 5.x
78. 5.x string(16) "PHP 5.x I see..."
79. 7.x
80. 7.x
81. 7.x
82. 7.x Notice: Array to string conversion in / foo.php on line 6 Notice: Undefined variable: Array in / foo.php on line 6
83. Funky
86. 7.x 5.x
87. FOUR Step @SammyK #mwphp17 joind.in/talk/82979
88. Code! @SammyK #mwphp17 joind.in/talk/82979
89. Tests TESTS Tests @SammyK #mwphp17 joind.in/talk/82979
90. PHPUnit? @SammyK #mwphp17 joind.in/talk/82979
91. Acceptance Tests @SammyK #mwphp17 joind.in/talk/82979
92. Codeception @SammyK #mwphp17 joind.in/talk/82979
93. Behavior-driven testing framework @SammyK #mwphp17 joind.in/talk/82979
94. Composer + Autoloading @SammyK #mwphp17 joind.in/talk/82979
95. @SammyK #mwphp17 joind.in/talk/82979
96. Feature (User Story)
97. Scenario
98. @SammyK #mwphp17 joind.in/talk/82979
99. Scenario @SammyK #mwphp17 joind.in/talk/82979
101. FIVE Step “The Refactoring Loop” @SammyK #mwphp17 joind.in/talk/82979
102. refactorLoop: @SammyK #mwphp17 joind.in/talk/82979
103. Start small @SammyK #mwphp17 joind.in/talk/82979
105. Make sure there’s a test @SammyK #mwphp17 joind.in/talk/82979
106. Refactor @SammyK #mwphp17 joind.in/talk/82979
107. Run your tests @SammyK #mwphp17 joind.in/talk/82979
108. goto refactorLoop; @SammyK #mwphp17 joind.in/talk/82979
109. lets you refactor like a BEAST @SammyK #mwphp17 joind.in/talk/82979
110. PHPUnit Don’t forget about
111. PHP 7.0 Features @SammyK #mwphp17 joind.in/talk/82979
112. random_int() random_bytes() PHP 7.0 Features CSPRNG!! @SammyK #mwphp17 joind.in/talk/82979
113. JOURNEY MY CENTER TO THE OF #ShamelessPlug Tomorrow @ 10 am in Main Ballroom
114. PHP 7.0 Features Scalar Type Declarations @SammyK #mwphp17 joind.in/talk/82979
115. PHP 7.0 Features Scalar Type Declarations function foo(string $name,
 int $age,
 bool $isGreat,
 float $income)
 { /* */ }
116. PHP 7.0 Features Scalar Type Declarations function foo(string $name,
 int $age,
 bool $isGreat,
 float $income)
 { /* */ }
117. PHP 7.0 Features Return type declarations @SammyK #mwphp17 joind.in/talk/82979
118. PHP 7.0 Features Return type declarations /**
 * @return Collection
 */
 public function foo()
 {
 }
119. PHP 7.0 Features /**
 * @return Collection
 */
 public function foo()
 {
 } Return type declarations
120. PHP 7.0 Features public function foo(): Collection
 {
 } Return type declarations
121. PHP 7.0 Features Null coalesce operator @SammyK #mwphp17 joind.in/talk/82979
122. PHP 7.0 Features $bar = isset($_GET[‘foo’]) ? $_GET[‘foo’] : null; Null coalesce operator $bar = $_GET[‘foo’] ?? null;
123. PHP 7.0 Features Insane speed improvements @SammyK #mwphp17 joind.in/talk/82979
124. PHP 7.1 Considerations & Features @SammyK #mwphp17 joind.in/talk/82979
125. PHP 7.1 Considerations deprecated ext/mcrypt Soon to be...
126. rand() & mt_rand() changes PHP 7.1 Considerations
128. Totes Samezies!
129. array_rand() Now with even distribution! PHP 7.1 Considerations
130. Void return types PHP 7.1 Features @SammyK #mwphp17 joind.in/talk/82979
131. public function foo(): void
 {
 } Void return types PHP 7.1 Features
132. Nullable types (kinda like union types for null) @SammyK #mwphp17 joind.in/talk/82979 PHP 7.1 Features
133. Nullable types function foo(string $name)
 { /* */ } PHP 7.1 Features
134. Nullable types function foo(?string $name)
 { /* */ } PHP 7.1 Features
135. Nullable types function foo(string $name = null)
 { /* */ } foo(); PHP 7.1 Features
136. Nullable types foo(); function foo(?string $name)
 { /* */ } foo(null); PHP 7.1 Features
137. Nullable types function foo(): ?string { return null; } PHP 7.1 Features
138. Class constant visibility @SammyK #mwphp17 joind.in/talk/82979 PHP 7.1 Features
139. Class constant visibility class Foo {
 public const FOO = 0; protected const BAR = 1; private const BAZ = 2; } PHP 7.1 Features
140. `iterable` pseudo-type @SammyK #mwphp17 joind.in/talk/82979 PHP 7.1 Features
141. `iterable` pseudo-type function foo(iterable $a)
 { /* */ } $b = []; foo($b); class C implements Iterator {} $b = new C; foo($b); PHP 7.1 Features
142. `iterable` pseudo-type class D implements IteratorAggregate {} foo(new D); Traversable Or instance of PHP 7.1 Features
143. And beyond? @SammyK #mwphp17 joind.in/talk/82979
144. PHP 7.2 Considering @SammyK #mwphp17 joind.in/talk/82979
145. PHP 7.2 considerations re(moved) ext/mcrypt
146. PHP 7.2 considerations Argon2 Password Hash password_*() (Could become new default in PHP 7.3/8.0)
147. Pending implementation… PHP 7.2
148. PHP 7.2 considerations sodium_*()
149. PHP 7.2 considerations Trailing Comma
150. 7.2 Deprecations (Will be removed by PHP 8.0)
151. Some tools I like @SammyK #mwphp17 joind.in/talk/82979
152. vlucas/phpdotenv .env No peeking! No peeking!
153. Some tools I like pimple/pimple @SammyK #mwphp17 joind.in/talk/82979
154. Some tools I like monolog/monolog @SammyK #mwphp17 joind.in/talk/82979
155. Some tools I like nikic/fast-route @SammyK #mwphp17 joind.in/talk/82979
156. Some tools I like illuminate/database @SammyK #mwphp17 joind.in/talk/82979
157. Some tools I like symfony/console @SammyK #mwphp17 joind.in/talk/82979
158. Create a PHP application without a framework https://github.com/PatrickLouys/no-framework-tutorial Patrick Louys @SammyK #mwphp17 joind.in/talk/82979
159. Big-picture Refactoring @SammyK #mwphp17 joind.in/talk/82979
160. Constant refactoring is the key to managing legacy codebases @SammyK #mwphp17 joind.in/talk/82979
161. Constant refactoring is the key to managing legacy codebases @SammyK #mwphp17 joind.in/talk/82979
162. Resources 013: TDD & BDD In PHP 055: Acceptance Testing with Behat 017: Modernizing Legacy Codebases in PHP @SammyK #mwphp17 joind.in/talk/82979
163. Modernizing Legacy Applications in PHP https://leanpub.com/mlaphp Paul M. Jones @SammyK #mwphp17 joind.in/talk/82979
164. Refactoring Martin Fowler http://martinfowler.com/books/refactoring.html @SammyK #mwphp17 joind.in/talk/82979
165. Takk! (thanks) @SammyK SammyK.me Host of @PHPRoundtable @ChiPHPUG West Coast Swing Hire me! :) /talk/82979