object-calisthenics / phpcs-calisthenics-rules
PHP CodeSniffer Object Calisthenics rules/sniffs
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Type:phpcodesniffer-standard
Requires
- php: ^7.4|^8.0
- nette/utils: ^3.1
- slevomat/coding-standard: ^6.3
- squizlabs/php_codesniffer: ^3.5
Requires (Dev)
- migrify/config-transformer: ^0.3.35
- phpstan/phpdoc-parser: ^0.4.9
- phpstan/phpstan: ^0.12.38
- phpunit/phpunit: ^9.3
- rector/rector: ^0.8.6
- symplify/changelog-linker: ^8.2
- symplify/coding-standard: ^8.2
- symplify/easy-coding-standard-tester: ^8.2
- symplify/phpstan-extensions: ^8.2
- tracy/tracy: ^2.7
README
DEPRECATED: PHP_CodeSniffer is great for handling spaces and char positions. Yet these rules are about code architecture and structure. In 2020, there is tool that suits this perfectly - PHPStan.
Saying that, object calisthenics were implemented as PHPStan rules in a symplify/phpstan-rules
package. Use it instead 👇
includes:
- vendor/symplify/phpstan-rules/packages/object-calisthenics/config/object-calisthenics-rules.neon
- vendor/symplify/phpstan-rules/packages/object-calisthenics/config/object-calisthenics-services.neon
Object Calisthenics are set of rules in object-oriented code, that focuses of maintainability, readability, testability and comprehensibility. We're pragmatic first - they are easy to use all together or one by one.
Why Should You Use This in Your Project?
Read post by William Durand or check presentation by Guilherme Blanco.
Install
composer require object-calisthenics/phpcs-calisthenics-rules --dev
Usage
If you know what you want, jump right to the specific rule:
- 1. Only X Level of Indentation per Method
- 2. Do Not Use "else" Keyword
- 5. Use Only One Object Operator (->) per Statement
- 6. Do not Abbreviate
- 7. Keep Your Classes Small
- 9. Do not Use Getters and Setters
How to quickly check 1 rule?
vendor/bin/phpcs src tests -sp \ --standard=vendor/object-calisthenics/phpcs-calisthenics-rules/src/ObjectCalisthenics/ruleset.xml \ --sniffs=ObjectCalisthenics.Classes.ForbiddenPublicProperty
# ecs.yaml services: ObjectCalisthenics\Sniffs\Classes\ForbiddenPublicPropertySniff: ~
then
vendor/bin/ecs check src
Implemented Rule Sniffs
1. Only X
Level of Indentation per Method
❌
foreach ($sniffGroups as $sniffGroup) { foreach ($sniffGroup as $sniffKey => $sniffClass) { if (! $sniffClass instanceof Sniff) { throw new InvalidClassTypeException; } } }
👍
foreach ($sniffGroups as $sniffGroup) { $this->ensureIsAllInstanceOf($sniffGroup, Sniff::class); } // ... private function ensureIsAllInstanceOf(array $objects, string $type) { // ... }
Use Only This Rule?
In PHP_CodeSniffer:
vendor/bin/phpcs ... --sniffs=ObjectCalisthenics.Metrics.MaxNestingLevel
In ECS:
# ecs.yaml services: ObjectCalisthenics\Sniffs\Metrics\MaxNestingLevelSniff: ~
🔧 Configurable
In PHP_CodeSniffer:
<?xml version="1.0"?> <ruleset name="my-project"> <rule ref="ObjectCalisthenics.Metrics.MaxNestingLevel"> <properties> <property name="maxNestingLevel" value="2"/> </properties> </rule> </ruleset>
In ECS:
services: ObjectCalisthenics\Sniffs\Metrics\MaxNestingLevelSniff: maxNestingLevel: 2
2. Do Not Use "else" Keyword
❌
if ($status === self::DONE) { $this->finish(); } else { $this->advance(); }
👍
if ($status === self::DONE) { $this->finish(); return; } $this->advance();
Use Only This Rule?
In PHP_CodeSniffer:
vendor/bin/phpcs ... --sniffs=ObjectCalisthenics.ControlStructures.NoElse
In ECS:
# ecs.yaml services: ObjectCalisthenics\Sniffs\ControlStructures\NoElseSniff: ~
5. Use Only One Object Operator (->
) per Statement
❌
$this->container->getBuilder()->addDefinition(SniffRunner::class);
👍
$containerBuilder = $this->getContainerBuilder(); $containerBuilder->addDefinition(SniffRunner::class);
Use Only This Rule?
In PHP_CodeSniffer:
vendor/bin/phpcs ... --sniffs=ObjectCalisthenics.CodeAnalysis.OneObjectOperatorPerLine
In ECS:
# ecs.yaml services: ObjectCalisthenics\Sniffs\CodeAnalysis\OneObjectOperatorPerLineSniff: ~
🔧 Configurable
In PHP_CodeSniffer:
<?xml version="1.0"?> <ruleset name="my-project"> <rule ref="ObjectCalisthenics.CodeAnalysis.OneObjectOperatorPerLine"> <properties> <property name="variablesHoldingAFluentInterface" type="array" value="$queryBuilder,$containerBuilder"/> <property name="methodsStartingAFluentInterface" type="array" value="createQueryBuilder"/> <property name="methodsEndingAFluentInterface" type="array" value="execute,getQuery"/> </properties> </rule> </ruleset>
In ECS:
services: ObjectCalisthenics\Sniffs\CodeAnalysis\OneObjectOperatorPerLineSniff: variablesHoldingAFluentInterface: ["$queryBuilder", "$containerBuilder"] methodsStartingAFluentInterface: ["createQueryBuilder"] methodsEndingAFluentInterface: ["execute", "getQuery"]
6. Do not Abbreviate
This is related to class, trait, interface, constant, function and variable names.
❌
class EM { // ... }
👍
class EntityMailer { // ... }
Use Only This Rule?
In PHP_CodeSniffer:
vendor/bin/phpcs ... --sniffs=ObjectCalisthenics.NamingConventions.ElementNameMinimalLength
In ECS:
# ecs.yaml services: ObjectCalisthenics\Sniffs\NamingConventions\ElementNameMinimalLengthSniff: ~
🔧 Configurable
In PHP_CodeSniffer:
<?xml version="1.0"?> <ruleset name="my-project"> <rule ref="ObjectCalisthenics.NamingConventions.ElementNameMinimalLength"> <properties> <property name="minLength" value="3"/> <property name="allowedShortNames" type="array" value="i,id,to,up"/> </properties> </rule> </ruleset>
In ECS:
# ecs.yaml services: ObjectCalisthenics\Sniffs\NamingConventions\ElementNameMinimalLengthSniff: minLength: 3 allowedShortNames: ["i", "id", "to", "up"]
7. Keep Your Classes Small
❌
class SimpleStartupController { // 300 lines of code }
👍
class SimpleStartupController { // 50 lines of code }
❌
class SomeClass { public function simpleLogic() { // 30 lines of code } }
👍
class SomeClass { public function simpleLogic() { // 10 lines of code } }
❌
class SomeClass { // 20 properties }
👍
class SomeClass { // 5 properties }
❌
class SomeClass { // 20 methods }
👍
class SomeClass { // 5 methods }
Use Only This Rule?
In PHP_CodeSniffer:
vendor/bin/phpcs ... --sniffs=ObjectCalisthenics.Files.ClassTraitAndInterfaceLength,ObjectCalisthenics.Files.FunctionLength,ObjectCalisthenics.Metrics.MethodPerClassLimit,ObjectCalisthenics.Metrics.PropertyPerClassLimit
In ECS:
# ecs.yaml services: ObjectCalisthenics\Sniffs\Files\ClassTraitAndInterfaceLengthSniff: ~ ObjectCalisthenics\Sniffs\Files\FunctionLengthSniff: ~ ObjectCalisthenics\Sniffs\Metrics\MethodPerClassLimitSniff: ~ ObjectCalisthenics\Sniffs\Metrics\PropertyPerClassLimitSniff: ~
🔧 Configurable
In PHP_CodeSniffer:
<?xml version="1.0"?> <ruleset name="my-project"> <rule ref="ObjectCalisthenics.Files.ClassTraitAndInterfaceLength"> <properties> <property name="maxLength" value="200"/> </properties> </rule> <rule ref="ObjectCalisthenics.Files.FunctionLength"> <properties> <property name="maxLength" value="20"/> </properties> </rule> <rule ref="ObjectCalisthenics.Metrics.PropertyPerClassLimit"> <properties> <property name="maxCount" value="10"/> </properties> </rule> <rule ref="ObjectCalisthenics.Metrics.MethodPerClassLimit"> <properties> <property name="maxCount" value="10"/> </properties> </rule> </ruleset>
In ECS:
# ecs.yaml services: ObjectCalisthenics\Sniffs\Files\ClassTraitAndInterfaceLengthSniff: maxLength: 200 ObjectCalisthenics\Sniffs\Files\FunctionLengthSniff: maxLength: 20 ObjectCalisthenics\Sniffs\Metrics\PropertyPerClassLimitSniff: maxCount: 10 ObjectCalisthenics\Sniffs\Metrics\MethodPerClassLimitSniff: maxCount: 10
9. Do not Use Getters and Setters
This rules is partially related to Domain Driven Design.
- Classes should not contain public properties.
- Method should represent behavior, not set values.
❌
class ImmutableBankAccount { public $currency = 'USD';
private $amount; public function setAmount(int $amount) { $this->amount = $amount; } }
👍
class ImmutableBankAccount { private $currency = 'USD';
private $amount; public function withdrawAmount(int $withdrawnAmount) { $this->amount -= $withdrawnAmount; } }
Use Only This Rule?
In PHP_CodeSniffer:
vendor/bin/phpcs ... --sniffs=ObjectCalisthenics.Classes.ForbiddenPublicProperty,ObjectCalisthenics.NamingConventions.NoSetter
In ECS:
# ecs.yaml services: ObjectCalisthenics\Sniffs\Classes\ForbiddenPublicPropertySniff: ~ ObjectCalisthenics\Sniffs\NamingConventions\NoSetterSniff: ~
🔧 Configurable
In PHP_CodeSniffer:
<?xml version="1.0"?> <ruleset name="my-project"> <rule ref="ObjectCalisthenics.NamingConventions.NoSetter"> <properties> <property name="allowedClasses" type="array" value="*\DataObject"/> </properties> </rule> </ruleset>
In ECS:
# ecs.yaml services: ObjectCalisthenics\Sniffs\NamingConventions\NoSetterSniff: allowedClasses: - '*\DataObject'
Not Implemented Rules - Too Strict, Vague or Annoying
While using in practice, we found these rule to be too strict, vague or even annoying, rather than helping to write cleaner and more pragmatic code. They're also closely related with Domain Driven Design.
3. Wrap Primitive Types and Strings - Since PHP 7, you can use define(strict_types=1)
and scalar type hints. For other cases, e.g. email, you can deal with that in your Domain via Value Objects.
4. Use First Class Collections - This rule makes sense, yet is too strict to be useful in practice. Even our code didn't pass it at all.
8. Do Not Use Classes With More Than Two Instance Variables - This depends on individual domain of each project. It doesn't make sense to make a rule for that.
3 Rules for Contributing
-
1 feature per PR
-
every new feature must be covered by tests
-
all tests and style checks must pass
composer complete-check
We will be happy to merge your feature then.