Example repo for building custom PHPCS sniffs

The idea is to go step by step through the repo and see how you can build up your custom sniff.

Chapters (organized by branches)

1. Project setup - installing the phpcs using Composer
2. Set up the sniffs folder and ruleset
3. Add the basis of our sniff - showcase using register and process methods
4. Add some tests and util packages like PhpCSDebug.
   1. Note - you can use composer scripts to check your code and run tests
   2. Note - using composer standards:check -- --standard=PhpCSDebug ./PhpCSExample/Tests/Strings/DisallowHelloWorldUnitTest.inc will list all the tokens in the test file - this helps a lot when writing sniffs, just to get your bearings
5. Update your sniff to catch some basic examples in tests
6. Add the first edge case and a way to solve it (only the echo 'hello', ' world'; part, the other edge case will fail, that's intentional!)
7. Add the fix for the edge case
8. Add documentation for your custom sniff
   1. You can check the documentation using vendor/bin/phpcs --standard=PhpCSExample --generator=Text
9. Add a failing edge case - string concatenation - this one you can figure out how to cover in the sniff :)

Tips and tricks

You can use different reports when running phpcs:

vendor/bin/phpcs PhpCSExample/Tests/Strings/DisallowHelloWorldUnitTest.inc --standard=PhpCSExample --report=code

You can run the phpcs in interactive mode, and fix things on the fly:

vendor/bin/phpcs PhpCSExample/Tests/Strings/DisallowHelloWorldUnitTest.inc --standard=PhpCSExample -a

You can use filters (useful if you use git hooks):

vendor/bin/phpcs PhpCSExample/Tests/Strings/DisallowHelloWorldUnitTest.inc --standard=PhpCSExample --filter=GitModified
vendor/bin/phpcs PhpCSExample/Tests/Strings/DisallowHelloWorldUnitTest.inc --standard=PhpCSExample --filter=GitStaged

You can ignore annotations (// phpcs:ignore comments) with --ignore-annotations

Useful links

Php_CodeSniffer

https://github.com/squizlabs/PHP_CodeSniffer/

External rulesets on Packagist

https://packagist.org/?query=phpcs&type=phpcodesniffer-standard https://packagist.org/?query=php_codesniffer&type=phpcodesniffer-standard

Dealerdirect Composer plugin for PHPCS

https://github.com/PHPCSStandards/composer-installer

Useful tools for sniff development

https://github.com/PHPCSStandards/PHPCSUtils https://github.com/PHPCSStandards/PHPCSDevTools