Mention PHP CodeSniffer, and most will think it’s just for style. Add passing PHP CodeSniffer to your test suites, and hear the groans. Why are we wasting time on whitespace rules? Why does it matter that my lines are longer than X characters? The answer: PHP CodeSniffer is more than just style. In this talk we will discuss what sniffs can save you from runtime errors, sniffs that can help you upgrade your PHP install, and sniffs that can help you find the bits of code that are slowing down you and your team.

1. It’s More Than Just Style
php|Tek ’12
May 23, 2012

2. LB Denker
@elblinkin an Etsy Admin

3. First Things That Come To Mind

4. What Difference Does
Whitespace Make?

5. With Modern Monitors,
Line Length Does Not
Matter.

6. It’s Just Style!

7. The Argument for Style

8. Requires Less Human Cognitive
Effort to Work with Code

9. Sniffs That Save You

10. Duplicate
Class Name
You can not have two classes or interfaces
with the same name

11. Duplicate
Function
Argument
You can not have two arguments in a
function with the same name

12. Static $this
Usage
$this requires an instance

13. Non-Executable
Code
Code after a return or exit will not be
executed

14. Valid
Default Value
All required arguments should precede
all optional arguments

15. Closing Tag
Avoid sending headers early

16. Minimal ruleset.xml
Run The Sniffs That Save You

17. PHPCS
ruleset.xml
Generator
http://edorian.github.com/php-coding-
standard-generator/#phpcs

18. Leading
Whitespace
Custom Sniff to Avoid sending headers
early

19. Full Report
Running phpcs

20. Summary Report
Running phpcs

21. Source Report
Running phpcs

22. XML Report
Running phpcs

23. CSV Report
Running phpcs

24. Emacs Report
Running phpcs

25. Blame Report(git|svn)
Running phpcs

26. Blame Report(git|svn)
Running phpcs

27. Checkstyle Report
Running phpcs

28. Checkstyle Plugin — Jenkins
Running phpcs in Jenkins

29. Checkstyle Plugin — Jenkins
Running phpcs in Jenkins

30. Checkstyle Plugin — Jenkins
Running phpcs in Jenkins

31. PHP Template
for Jenkins
http://jenkins-php.org/

32. Step Back for a Minute

33. Don’t Forget Lint
php -l

34. Steps To Clean Code
✤ Start with Syntax
✤ Move to Style
✤ Then Design... maybe

35. Standards to Drive Conventions

36. Etsy Custom Sniffs
✤ Goto ✤ Integration Test
✤ Disallow goto ✤ Ensure that All Tests in a
@group are Marked @medium
✤ SvnTag or Higher
✤ Disallow SVN Tags
ie. $Date$ or $Revision$ ✤ Test Group
✤ Ensure that All Tests are
✤ UnnecessaryComment Marked in a @group that
✤ Disallow phpDoc Tags that Exists
Repeat Info in Source Control
ie. @author

37. Standards to Move You Forward

38. Sniff Out
Backwards
Incompatibility
Coding Standards to Help You Upgrade

39. Upgrade to PHP 5.3
✤ Deprecated Functions
✤ Deprecated ini Directives
✤ Deprecated new Reference Return
✤ Forbidden Names, Reserved Keywords
✤ Non-Static Magic Methods, Ensure
✤ Removed Extensions
https://github.com/wimg/PHP53Compat_CodeSniffer

40. Compatibility Through PHP 5.4
✤ Default Timezone Required
✤ Deprecated Functions
✤ Deprecated ini Directives
✤ Deprecated new Reference Return
✤ Forbidden continue and break Variable Arguments
✤ Forbidden Names, Reserved Keywords
✤ Non-Static Magic Methods, Ensure
✤ Removed Extensions
✤ Removed Hash Algorithms
https://github.com/wimg/PHPCompatibility

41. Standards to Save You Time

42. PHPUnit Coding Standard
✤ Ensures Tests are Executable
✤ Reduces Superfluous Code
✤ Increases Readability
✤ Decreases Debug Time

43. Minimal phpunit-ruleset.xml
Run The Sniffs That Save You

44. Code Sniffer Limitations

45. How Code Sniffer Basically Works
✤ Gets array of Tokens from token_get_all()
✤ Creates Abstract Syntax Tree (AST)
✤ Analyzes Each File Individually, Sequentially
✤ Collects All Parsed, Analyzed Files in an array for Multi-File Sniffs

46. CSRunner
Only analyze recent changes
https://github.com/elblinkin/CSRunner

47. HpHp as a Static Analyzer
✤ Pros ✤ Cons
✤ Very Fast Static Analysis ✤ Not Easy to Install
✤ Call Graph Analysis ✤ Takes a Decent Amount of
Configuration
✤ HpHp Analyzer Creates
Checkstyle Reports

48. Beyond Code Sniffer

49. Steps To Clean Code
✤ Start with Syntax
✤ Move to Style
✤ Then Design... maybe

50. Enforcing a Standard
✤ Draft a Coding Standard
✤ Experiment with Various Sniffs, Tweak Sniffs
✤ Discover Actual Coding Tendencies
✤ Decide on Changes to Coding Standard Based on Previous Steps
✤ Strategize on How to Get to GREEN

51. PHP Community Standard
✤ Checkout PSR-1
✤ Checkout PSR-2
✤ Just-in: PHP Coding Standards Fixer
✤ http://cs.sensiolabs.org/

52. Moving Towards Enforcement
✤ Assign Violations via blame
✤ Create a Staging Set that Can Be Ignored in an Emergency
✤ Fix-It Competition or Party

53. Steps To Clean Code
✤ Start with Syntax
✤ Move to Style
✤ Then Design... maybe

54. PHP
Mess Detector
http://phpmd.org/

55. ✤ http://phpadvent.org/2011/more-than-just-style-by-
laura-beth-denker
✤ http://codeascraft.com
✤ http://www.slideshare.net/Etsy
✤ http://elblinkin.info
✤ http://www.lornajane.net/posts/2009/php-code-
sniffer-tutorial-on-techportal