Load commands from all PSR-4 Autoload namespaces

Kernel.php

<?php

namespace App\Console;

use Illuminate\Console\Application as Artisan;
use Illuminate\Console\Command;
use Illuminate\Foundation\Console\Kernel as ConsoleKernel;
use ReflectionClass;
use Symfony\Component\Finder\Finder;

class Kernel extends ConsoleKernel
{
    public function commands()
    {
        $this->autoload([
            base_path('project/Commands')
        ]);
    }

    /**
     * @throws \ReflectionException
     */
    private function autoload($paths)
    {
        $paths = array_unique(is_array($paths) ? $paths : [$paths]);
        $paths = array_filter($paths, 'is_dir');

        if (empty($paths)) {
            return;
        }

        $autoloadNamespaces = $this->getAutoloadNamespaces();
        foreach ((new Finder())->in($paths)->files() as $file) {
            $path = $file->getRealPath();
            foreach ($autoloadNamespaces as $basePath => $namespace) {
                if (substr($path, 0, strlen($basePath)) !== $basePath) {
                    continue;
                }

                $class = $namespace . str_replace(['/', '.php'], ['\\', ''], substr($path, strlen($basePath)));
                if (is_subclass_of($class, Command::class) && !(new ReflectionClass($class))->isAbstract()) {
                    Artisan::starting(function ($artisan) use ($class) {
                        $artisan->resolve($class);
                    });
                }
            }
        }
    }

    private function getAutoloadNamespaces(): array
    {
        $result   = [app_path() . DIRECTORY_SEPARATOR => app()->getNamespace()];
        $composer = json_decode(file_get_contents(base_path('composer.json')), true);
        foreach ((array) data_get($composer, 'autoload.psr-4') as $namespace => $path) {
            $path = realpath(base_path($path)) ?: realpath($path);
            if ($path) {
                $result[$path . DIRECTORY_SEPARATOR] = $namespace;
            }
        }

        return $result;
    }
}