Laravel, first user is only user - php

Question

I am building a Laravel site for personal use and I would like to make the first user to register on the site be the only user. So with a fresh Laravel install with the ui installed, migration sorted and no users registered, I would like the register route to be reachable. But if there is a registered user, block the register route and only allow the login route to be reachable.
I could do something like this in the web.php
Route:get('/register', function () {...})->auth();
But I would have to do that after I first create a user. I'd rather do it in a more controllable fashion.
Edit
I don't doubt that #yves-kipondo's answer is the more correct option if I were to create this for someone else.
The solution I went with is a simple one. In my register controller I just add a check in the constructor, if there already is a user return a 404.
public function __construct() {
if (!User::all()) {
$this->middleware('guest');
} else {
abort(404);
}
}

Answer 1

You can create a Middleware which will be register on the register route
<?php
namespace App\Http\Middleware;
use Closure;
class RegisterOnce
{
/**
* Handle an incoming request.
*
* #param \Illuminate\Http\Request $request
* #param \Closure $next
* #return mixed
*/
public function handle($request, Closure $next)
{
if (User::count() !== 0) {
// you can redirect wherever you want
return redirect('home');
}
return $next($request);
}
}
After that you can register the middleware in the app/Http/Kernel.php by adding this line after all registered routes middleware like this
protected $routeMiddleware = [
\\ ... previous registered middleware
'once' => App\Http\Middleware\RegisterOnce::class,
];
and you can customize the register route like this in the routes/web.php file
which wille replace the default set by Auth::routes();
Route::get('register', [App\Controllers\Auth\RegisterController::class, 'showRegistrationForm'])
->name('register')
->middleware('once');