ldc-crm/app/Http/Middleware/JsonOnly.php

<?php

namespace App\Http\Middleware;

use App\Lib\Helper;
use Illuminate\Http\Request;

class JsonOnly
{
    /**
     * Handle an incoming request.
     *
     * @param  \Illuminate\Http\Request $request
     * @param  \Closure                 $next
     * @return mixed
     */
    public function handle(Request $request, \Closure $next)
    {
        // TODO remove condition v1 check when dropped.
        if (
            !Helper::isRequestForApiV1($request) and
            (!$request->isJson() or
                !$request->expectsJson() or
                is_null(json_decode($request->getContent())))
        ) {
            abort(400, 'Invalid JSON');
        }

        return $next($request);
    }
}