snipe-it/app/Http/Requests/SaveUserRequest.php

<?php

namespace App\Http\Requests;

use App\Http\Requests\Request;
use App\Models\Setting;

class SaveUserRequest extends Request
{
    /**
     * Determine if the user is authorized to make this request.
     *
     * @return bool
     */
    public function authorize()
    {
        return true;
    }

    /**
     * Get the validation rules that apply to the request.
     *
     * @return array
     */
    public function rules()
    {

        $rules = [];

        switch($this->method())
        {

            // Brand new asset
            case 'POST':
            {
                $rules['first_name'] = 'required|string|min:1';
                $rules['username'] = 'required|string|min:1';
                $rules['password'] = Setting::passwordComplexityRulesSaving('store');
            }

            // Save all fields
            case 'PUT':
                $rules['first_name'] = 'required|string|min:1';
                $rules['username'] = 'required|string|min:1';
                $rules['password'] = Setting::passwordComplexityRulesSaving('update');

            // Save only what's passed
            case 'PATCH':
            {
                $rules['password'] = Setting::passwordComplexityRulesSaving('update');
            }

            default:break;
        }

        $rules['password_confirm'] = 'sometimes|required_with:password';

        return $rules;

    }
}