Dead code detector for PHP

PHPStan extension to find unused PHP code in your project with ease!

Installation:

composer require --dev shipmonk/dead-code-detector

Use official extension-installer or just load the rules:

includes:
    - vendor/shipmonk/dead-code-detector/rules.neon

Supported libraries

• Any overridden method that originates in vendor is not reported as dead
• We also support many magic calls in following libraries:

Symfony:

• constructor calls for DIC services!
  • phpstan/phpstan-symfony with containerXmlPath must be used
• #[AsEventListener] attribute
• #[AsController] attribute
• #[AsCommand] attribute
• #[Required] attribute
• #[Route] attributes
• onKernelResponse, onKernelRequest, etc

Doctrine:

• #[AsEntityListener] attribute
• Doctrine\ORM\Events::* events
• Doctrine\Common\EventSubscriber methods
• lifecycle event attributes #[PreFlush], #[PostLoad], ...

PHPUnit:

• data provider methods
• testXxx methods
• annotations like @test, @before, @afterClass etc
• attributes like #[Test], #[Before], #[AfterClass] etc

PHPStan:

• constructor calls for DIC services (rules, extensions, ...)

Nette:

• handleXxx, renderXxx, actionXxx, injectXxx, createComponentXxx
• SmartObject magic calls for @property annotations

All those libraries are autoenabled when found within your composer dependencies. If you want to force enable/disable some of them, you can:

# phpstan.neon.dist
parameters:
    shipmonkDeadCode:
        entrypoints:
            phpunit:
                enabled: true

Customization:

• If your application does some magic calls unknown to this library, you can implement your own entrypoint provider.
• Just tag it with shipmonk.deadCode.entrypointProvider and implement ShipMonk\PHPStan\DeadCode\Provider\MethodEntrypointProvider
• You can simplify your implementation by extending ShipMonk\PHPStan\DeadCode\Provider\MethodBasedEntrypointProvider

# phpstan.neon.dist
services:
    -
        class: App\ApiOutputEntrypointProvider
        tags:
            - shipmonk.deadCode.entrypointProvider

use ReflectionMethod;
use ShipMonk\PHPStan\DeadCode\Provider\SimpleMethodEntrypointProvider;

class ApiOutputEntrypointProvider extends SimpleMethodEntrypointProvider
{

    public function isEntrypointMethod(ReflectionMethod $method): bool
    {
        return $method->getDeclaringClass()->implementsInterface(ApiOutput::class));
    }
}

Comparison with tomasvotruba/unused-public

• You can see detailed comparison PR
• Basically, their analysis is less precise and less flexible. Mainly:
  • It cannot detect dead constructors
  • It does not properly detect calls within inheritance hierarchy
  • It does not offer any custom adjustments of used methods
  • It has almost no built-it library extensions
  • It ignores trait methods
  • Is lacks many minor features like class-string calls, dynamic method calls, array callbacks, nullsafe call chains etc

Limitations:

• Only method calls are detected so far
  • Including constructors, static methods, trait methods, interface methods, first class callables, clone, etc.
  • Any calls on mixed types are not detected, e.g. $unknownClass->method()
  • Anonymous classes are ignored (PHPStan limitation)
  • Does not check most magic methods (__get, __set etc)
  • Call-graph not implemented so far
    • No transitive check is performed (dead method called only from dead method)
    • No dead cycles are detected (e.g. dead method calling itself)

Contributing

• Check your code by composer check
• Autofix coding-style by composer fix:cs
• All functionality must be tested

Supported PHP versions

• PHP 7.4 - 8.3