staffmanager/app/Http/Requests/ChangeEmailRequest.php

<?php

namespace App\Http\Requests;

use Illuminate\Foundation\Http\FormRequest;

class ChangeEmailRequest extends FormRequest
{
    /**
     * 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()
    {
        return [
            'currentPassword' => 'required|password',
            'newEmail' => 'required|email|unique:users,email'
        ];
    }
}