[WIP] Add PHP 8 support and configuration by attributes

[zluiten]

Re #2

This adds support for the following:

• PHP 8
• Configure service definition by attribute (EventEngine\Discolight\ServiceDefinition).
• Register multiples instances of the same type (but f.e. with a different factory method).
• Register instances under more than 1 service id. This needs a second though because it behaves like aliases. It was inferred based on 1) attributes can be added more than once 2) PHP 8 (return) union types.
• Register instances with a builtin return type (like callable)

Above list is available for PHP 8 only but doesn't break applications running PHP 7.

Example 1:

use EventEngine\Discolight\ServiceDefinition;
use Mezzio\Authentication\UserInterface;
use Mezzio\Authentication\DefaultUser;

final class ServiceFactory
{
    #[ServiceDefinition('Mezzio\Authentication\UserInterface')]
    public function userFactory(): callable
    {
        return $this->makeSingleton(UserInterface::class, function () {
            return function (string $identity, array $roles = [], array $details = []): UserInterface {
                Assert::allString($roles);
                Assert::isMap($details);

                return new DefaultUser($identity, $roles, $details);
            };
        });
    }
}

$serviceFactory = new ServiceFactory();
$container = new Discolight($serviceFactory);
$serviceFactory->setContainer($container);

$userFactory = $container->get(Mezzio\Authentication\UserInterface::class);

Example 2:

use EventEngine\Discolight\ServiceDefinition;
use Mezzio\Authentication\AuthenticationInterface;
use Mezzio\Authentication\UserInterface;

final class ServiceFactory
{
    #[ServiceDefinition('middleware.basic-auth')]
    public function basicAuthenticationMiddleware(): AuthenticationMiddleware
    {
        return $this->makeSingleton('middleware.basic-auth', function () {
            return new AuthenticationMiddleware($this->basicAuthenticationAdapter());
        });
    }

    #[ServiceDefinition('middleware.jwt-auth')]
    public function jwtAuthenticationMiddleware(): AuthenticationMiddleware
    {
        return $this->makeSingleton('middleware.jwt-auth', function () {
            return new AuthenticationMiddleware($this->jwtAuthenticationAdapter());
        });
    }
    
    protected function basicAuthenticationAdapter(): AuthenticationInterface
    {
        // return authentication adapter
    }
    
    protected function jwtAuthenticationAdapter(): AuthenticationInterface
    {
        // return authentication adapter
    }
}

$serviceFactory = new ServiceFactory();
$container = new Discolight($serviceFactory);
$serviceFactory->setContainer($container);

$basicAuthMiddleware = $container->get('middleware.basic-auth');
$jwtAuthMiddleware = $container->get('middleware.jwt-auth');

Fixed some unreachable code as well. The null check in the following code can not happen:

if ($returnType = $method->getReturnType()) {
    if (! $returnType->isBuiltin()) {
        $returnType = $method->getReturnType();
        if (null === $returnType) {
            throw new \RuntimeException(\sprintf(
                'The returnType of function %s is weird and breaks our system...',
                $method->getName()
            ));
         }

Oh, and I've removed the prooph/php-cs-fixer-config dependency for now, since it's not PHP 8 ready yet.

[codeliner]

I like the changes, but I'm not sure if we should merge it here or instead add PHP 8 attribute support to https://github.com/bitExpert/disco

As stated in the readme: Discolight is inspired by disco. Hence, the name ;)
We really like the DI container developed by @shochdoerfer, but wanted a light version without doc block annotations. Now with PHP 8 available the situation has changed. If disco will support PHP 8 attributes - and I'm sure Stephan is interested - we could switch back to disco as the default DI container for Event Engine.

@shochdoerfer , @Netiul , @sandrokeil What do you think?

[shochdoerfer]

That would be lovely. I had plans to create a version 1.0 of Disco supporting PHP 8 but I could not yet find the time to get started. I am more than willing to support this movement.

[zluiten]

Ah, I came to this library via event-engine and I think it's really good. Never looked any further even though https://github.com/bitExpert/disco is indeed credited. I'm more than happy to move these changes and see if @shochdoerfer likes it.

[sandrokeil]

Yes, we should go to that Disco, if they will play PHP 8 attributes. ;-)
@Netiul Would be nice if you can help @shochdoerfer with the implementation.

[shochdoerfer]

@Netiul feel free to open an issue in the Disco repo to discuss things. I assume we need to change quite a bit but that should not stop us ;)

[shochdoerfer]

ping @heiglandreas just in case you are bored during the Christmas holidays :P