test/app/Http/Middleware/LogonRedirect.php

<?php

namespace App\Http\Middleware;

use Closure;
use Illuminate\Support\Facades\Auth;

class LogonRedirect
{
    /**
     * Handle an incoming request.
     *
     * @param  \Illuminate\Http\Request $request
     * @param  \Closure $next
     * @return mixed
     */
    public function handle($request, Closure $next)
    {
        if (!$request->ajax()) {
            if (Auth::check()) {
                return redirect('/admin');
            }
        }
        return $next($request);
    }
}