App\Services\Form\User\UserFormLaravelValidator::rules PHP Method

    protected function rules()
    {
        $rules = [];
        // For role
        if (isset($this->data['role'])) {
            foreach ($this->data['role'] as $key => $val) {
                $rules["role.{$key}"] = 'required|exists:roles,id';
            }
        }
        // For email
        $unique = 'unique:users,email';
        if (isset($this->data['id'])) {
            $unique .= ',' . $this->data['id'];
        }
        $rules['email'] = "sometimes|required|email|{$unique}";
        return $rules;
    }