Laravel 5 how to validate route parameters?

Override the all() function on the Request object to automatically apply validation rules to the URL parameters

class SetEmailRequest
{

    public function rules()
    {
        return [
            'email'    => 'required|email|max:40',
            'id'       => 'required|integer', // << url parameter
        ];
    }

    public function all()
    {
        $data = parent::all();
        $data['id'] = $this->route('id');

        return $data;
    }

    public function authorize()
    {
        return true;
    }
}

Access the data normally from the controller like this, after injecting the request:

$setEmailRequest->email // request data
$setEmailRequest->id, // url data

For Laravel < 5.5:
The way for this is overriding all() method for CheckTokenServerRequest like so:

public function all() 
{
   $data = parent::all();
   $data['token'] = $this->route('token');
   return $data;
}

EDIT
For Laravel >= 5.5:
Above solution works in Laravel < 5.5. If you want to use it in Laravel 5.5 or above, you should use:

public function all($keys = null) 
{
   $data = parent::all($keys);
   $data['token'] = $this->route('token');
   return $data;
}

instead.