firefly-iii/app/Http/Requests/CategoryFormRequest.php

<?php
/**
 * CategoryFormRequest.php
 * Copyright (c) 2017 thegrumpydictator@gmail.com
 *
 * This file is part of Firefly III.
 *
 * Firefly III is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Firefly III is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Firefly III.  If not, see <http://www.gnu.org/licenses/>.
 */
declare(strict_types=1);

namespace FireflyIII\Http\Requests;

use FireflyIII\Repositories\Category\CategoryRepositoryInterface;

/**
 * Class CategoryFormRequest.
 */
class CategoryFormRequest extends Request
{
    /**
     * @return bool
     */
    public function authorize()
    {
        // Only allow logged in users
        return auth()->check();
    }

    /**
     * @return array
     */
    public function getCategoryData(): array
    {
        return [
            'name' => $this->string('name'),
        ];
    }

    /**
     * @return array
     */
    public function rules()
    {
        /** @var CategoryRepositoryInterface $repository */
        $repository = app(CategoryRepositoryInterface::class);
        $nameRule   = 'required|between:1,100|uniqueObjectForUser:categories,name';
        if (null !== $repository->find(intval($this->get('id')))->id) {
            $nameRule = 'required|between:1,100|uniqueObjectForUser:categories,name,' . intval($this->get('id'));
        }

        // fixed
        return [
            'name' => $nameRule,
        ];
    }
}