Simplified Mezzio Application

composer.json

{
    "name": "asgrim/mezzio-simplified",
    "description": "Simplified Mezzio project",
    "type": "project",
    "require": {
        "php": "^7.4",
        "mezzio/mezzio": "^3.2",
        "laminas/laminas-diactoros": "^2.3",
        "laminas/laminas-servicemanager": "^3.4",
        "mezzio/mezzio-fastroute": "^3.0"
    },
    "license": "MIT"
}

index.php

<?php
/** @noinspection TransitiveDependenciesUsageInspection */
declare(strict_types=1);

require __DIR__ . '/../vendor/autoload.php';

use Laminas\Diactoros\Response;
use Laminas\Diactoros\Response\TextResponse;
use Laminas\Diactoros\ServerRequestFactory;
use Laminas\HttpHandlerRunner\Emitter\SapiEmitter;
use Laminas\HttpHandlerRunner\RequestHandlerRunner;
use Laminas\ServiceManager\ServiceManager;
use Laminas\Stratigility\MiddlewarePipe;
use Mezzio\Application;
use Mezzio\MiddlewareContainer;
use Mezzio\MiddlewareFactory;
use Mezzio\Response\ServerRequestErrorResponseGenerator;
use Mezzio\Router\FastRouteRouter;
use Mezzio\Router\Middleware\DispatchMiddleware;
use Mezzio\Router\Middleware\RouteMiddleware;
use Mezzio\Router\RouteCollector;
use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ServerRequestInterface;
use Psr\Http\Server\RequestHandlerInterface;

$container = new ServiceManager();

$router = new FastRouteRouter();
$middlewarePipe = new MiddlewarePipe();
$app = new Application(
    new MiddlewareFactory(new MiddlewareContainer($container)),
    $middlewarePipe,
    new RouteCollector($router),
    new RequestHandlerRunner(
        $middlewarePipe,
        new SapiEmitter(),
        static function () {
            return ServerRequestFactory::fromGlobals();
        },
        new ServerRequestErrorResponseGenerator(
            static function () : Response {
                return new Response();
            },
            true
        )
    )
);
$app->pipe(new RouteMiddleware($router));
$app->pipe(new DispatchMiddleware());
$app->get('/hello', new class implements RequestHandlerInterface {
    public function handle(ServerRequestInterface $request): ResponseInterface
    {
        return new TextResponse('hello world');
    }
});
$app->run();