Introducing Object Calisthenics Rules for PHPStan
For the last 2 years, I've maintained Object Calisthenics Rules for PHP_CodeSniffer. In 2019 and 2020, there was a huge boom of custom PHPStan rulesets that make everyday development easier and stronger at the same time.
Have you been waiting to put these rules into your
Today you can!
Object Calisthenics is about SOLID rules and code architecture more than spaces and bracket positions, maybe PHPStan and AST are better to handle it?
What is Object Calis...?
Oh wait, it's the first time you hear Object Calisthenics?
Don't worry. It's not a physical sport that is required to become a better developer. You read about all 9 rules or listen to 12-min audio in Object Calisthenics post by William Durand or check colorful slides by Guilherme Blanco, the former maintainer PHP_CodeSniffer set package.
Some of the rules are rather theoretical to entertain the mind, but some can be measured. And what can be measured, can be automated. What rules can you check in your CI?
- Rule 1: Only X Level of Indentation per Method
- Rule 2: No
- Rule 5: No Chain Method Call
- Rule 6: No Names Shorter than 3 Chars
- Rule 7: Keep Your Classes Small
- Rule 9: No Setter Methods
Introducing PHPStan Rules
You can add all of the rules above as a PHPStan ruleset. I've ported these rules to
symplify/coding-standard in the last 2 days.
composer require symplify/coding-standard --dev
# phsptan.neon includes: - vendor/symplify/coding-standard/packages/object-calisthenics/config/object-calisthenics-rules.neon
As you can see, their rules are pretty strict, and in practice, that might be impossible to put on a real project. It's better to start slowly with low hanging fruit rules. Like these 2:
Rule 5: No Chain Method Call
# phpstan.neon rules: - Symplify\CodingStandard\ObjectCalisthenics\Rules\NoChainMethodCallRule
Rule 6: No Names Shorter than 3 Chars
# phpstan.neon services: - class: Symplify\CodingStandard\ObjectCalisthenics\Rules\NoShortNameRule tags: [phpstan.rules.rule] arguments: minNameLength: 3 allowedShortNames: ['id', 'to', 'up']
And you're ready to go!
How to Switch from PHP_CodeSniffer to PHPStan rules?
Most likely, you're not using all the rules at once, so we look at migrating particular rules.
- Look at the list of PHPStan rules
- Look at the full set -
- Pick the rules you need and copy-paste them to your
- You can use parameters to configure them, or explicit values (like in 2 cases above)
- Add only 1 rule at a time and then try to run PHPStan (
vendor/bin/phpstan analyse) to make sure, it works
Good luck and have fun.