java - 不影响返回的条件的突变测试

Question

我正在为我的函数运行一个坑突变测试，我似乎无法为否定条件覆盖这条线。所以这是一个 if 语句，它执行一个子字符串来为服务调用构建一个 url。

public List<Player> retrievePlayers(List<String> playerIds) throws error {


    List<Player> players = new ArrayList<Player>();

    ResponseEntity<String> playerDetails;

    String currentPlayerId = null;

    for(String playerId : playerIds) {
        currentPlayerId = playerId;

        if (playerId.length() == 15) { 
            currentPlayerId = playerId.substring(0,10); 
        }
    }

    try {
        playerDetails = playerFetchDelegate.getPlayerDetails(currentPlayerId);
        convertResponseToObject(playerDetails, players);
    } catch (exception) {
        throw new exception
    }

    }
    return players;
}

所以突变没有覆盖 if 语句，因为条件不会改变返回。我怎样才能覆盖这条线？

谢谢！