One Request for User creation and editing

UserRequest.php

<?php

namespace App\Http\Requests;

use Illuminate\Foundation\Http\FormRequest;

class UserRequest extends FormRequest
{
    protected $base_rules = [
        'name' => 'required|string|max:255',
        'email' => 'required|string|email|max:255',
        'username' => 'required|string|max:255',
        'password' => 'string|min:6',
    ];

    protected $create_rules = [
        'name' => 'required|string|max:255',
        'email' => 'required|string|email|max:255|unique:users',
        'username' => 'required|string|max:255',
        'password' => 'string|min:6',
    ];

    protected $add_role_rules = [
        'role' => 'required'
    ];

    /**
     * Determine if the user is authorized to make this request.
     *
     * @return bool
     */
    public function authorize()
    {
        return ! auth()->guest();
    }

    /**
     * Get the validation rules that apply to the request.
     *
     * @return array
     */
    public function rules()
    {
        switch ($this->get('action')) {
            case 'edit':
                if ($this->has('password')) {
                    return $this->base_rules;
                }

                return collect($this->base_rules)->except('password')->toArray();
                break;

            case 'create':
                return $this->create_rules;
                break;

            case 'role':
                return $this->add_role_rules;
                break;

            default:
                return $this->base_rules;
                break;
        }
    }
}