MessageAccess::checkAccessForChat

static function checkAccessForChat(int $chatId, int $userId): bool
{
	if (MainLoader::includeModule('im'))
	{
		$data = CIMChat::GetChatData(['ID' => $chatId]);
		$userInChat = $data['userInChat'][$chatId] ?? [];
		if (in_array($userId, $userInChat, true))
		{
			return true;
		}
	}

	return false;
}