README

PHPStan extensions for dependency injection containers. Provides dynamic return type resolution so PHPStan understands that $container->get(Foo::class) returns Foo.

Supported Containers

• StellarWP Container Contract (StellarWP\ContainerContract\ContainerInterface)
• PSR-11 Container (Psr\Container\ContainerInterface)
• Any container really as long as you pass its fully qualified class name to the extension as an argument.

Requirements

• PHP 7.4 or higher
• PHPStan 2.0 or higher

Installation

composer require --dev dpanta94/phpstan-containers

If you use phpstan/extension-installer, you're all set!

Manual Installation

If you don't use the extension installer, add the extension to your phpstan.neon:

includes:
    - vendor/dpanta94/phpstan-containers/extension.neon

Usage

Once installed, PHPStan will automatically understand container return types:

use Psr\Container\ContainerInterface;

class MyService {
    public function __construct(private ContainerInterface $container) {}

    public function doSomething(): void {
        // PHPStan knows $logger is an instance of Logger
        $logger = $this->container->get(Logger::class);
        $logger->info('Hello world');

        // PHPStan knows $mailer is an instance of MailerInterface
        $mailer = $this->container->get(MailerInterface::class);
        $mailer->send($message);
    }
}

The extension resolves types when:

• The argument to get() is a class-string constant (e.g., Foo::class)
• The class or interface exists in the codebase

When using string service IDs (e.g., $container->get('mailer')), the extension falls back to the default mixed return type.

Prefixed containers (Strauss / Mozart)

PHPStan keys dynamic return type extensions by the class returned from getClass() and only consults them when the value's type has that class in its ancestry. If you ship your dependencies through a namespace prefixer such as Strauss or Mozart, your container interface is rewritten (e.g. StellarWP\ContainerContract\ContainerInterface becomes Acme\Vendor\StellarWP\ContainerContract\ContainerInterface). The bundled StellarWP and PSR extensions can no longer match it, because the prefixed copy shares no ancestor with the original interface.

Register ConfigurableContainerDynamicReturnTypeExtension once per prefixed container interface in your phpstan.neon:

services:
    -
        class: DPanta\PHPStan\Containers\ConfigurableContainerDynamicReturnTypeExtension
        arguments:
            containerClass: Acme\Vendor\StellarWP\ContainerContract\ContainerInterface
        tags:
            - phpstan.broker.dynamicMethodReturnTypeExtension

The bundled defaults remain registered, so unprefixed containers keep working with zero configuration.

License

MIT

Credits

This package is inspired by Phil Nelson's phpstan-container-extension.