Discord.js 不检查参数是否存在

Question

我正在尝试使用 discord.js 和 minecraft-server-util 编写 Minecraft 服务器信息检查器，但会检查 args 是否存在或只有 1 个参数不起作用，并且它正在通过这些检查而无所事事错了，但是当我不包含任何内容时，server-util 部分会向控制台发送错误“预期主机（参数）有内容，得到一个空字符串”如果你能帮助我，我不确定问题是什么那就太好了。

命令名称：@javaserverstatus 命令和前缀是 17 个字符，这就是为什么 slice 设置为 17。

client.on('message', (message) => {
  const args = message.content.slice(17).trim().split(' ') // this is where args is defined.
  if (message.content === `${prefix}javaserverstatus`) {
    if (!args.length) {
      return message.channel.send(`You didn't provide a server, ${message.author}!`) // checks if args exist
    }
    if (args.length > 1) {
      return message.channel.send(`Wrong input! EG. play.hypixel.net, ${message.author}`) // checks if there are only 1 arguments
    }
  }
  const util = require('minecraft-server-util')
  var serverinfo = null
  util
    .status(args.toString()) // This code is giving an error saying args does not exist.
    .then((response) => {
      console.log(response)
      serverinfo = response
      const embed = new Discord.MessageEmbed()
        .setTitle(args + ' Server Status')
        .setColor(0xff0000)
        .setDescription('IP: ' + response.host + '\n' + 'Port: ' + response.port + '\n' + 'Version: ' + response.version + '\n' + 'Online Players: ' + response.onlinePlayers.toString() + '\n' + 'Max Players: ' + response.maxPlayers.toString() + '\n')
      message.channel.send(embed)
    })
    .catch((error) => {
      console.error(error)
    })
})

Answer 1

即使消息不是命令，您的命令代码仍在运行。

例如，消息"hi" 将导致参数为[""]。然后它会简单地忽略 if 语句并运行您的命令。

此外，如果消息是 "{prefix}javaserverstatus"，则它的 args 长度始终为 1 ([""])。

另外需要注意的是，如果消息也是"{prefix}javaserverstatus some arguments"，则验证数据的 if 语句不会运行，因为消息不再等于 ${prefix}javaserverstatus。

您应该将代码修复为仅在命令实际运行时运行，并正确验证您的数据：

client.on("message", (message) => {
  // create args
  const args = message.content.slice(17).trim().split(" ");

  // fits the command, including arguments, not just a blank command
  if (message.content.startsWith(`${prefix}javaserverstatus`)) {
    // args.length will always be 1 or greater.
    // instead, check if the first argument is an empty string.
    if (args[0] === "") {
      return message.channel.send(`You didn't provide a server, ${message.author}!`); // checks if args exist
    }
    if (args.length > 1) {
      return message.channel.send(`Wrong input! EG. play.hypixel.net, ${message.author}`) // checks if there are only 1 arguments
    }

    // only if the command is valid, then run the command.
    const util = require('minecraft-server-util');
    let serverinfo = null;
    util
      .status(args.toString())
      .then((response) => {
        console.log(response);
        serverinfo = response;
        const embed = new Discord.MessageEmbed()
          .setTitle(args + " Server Status")
          .setColor(0xff0000)
          .setDescription("IP: " + response.host + "\n" + "Port: " + response.port + "\n" + "Version: " + response.version + "\n" + "Online Players: " + response.onlinePlayers.toString() + "\n" + "Max Players: " + response.maxPlayers.toString() + "\n")
        message.channel.send(embed);
      })
      .catch((error) => {
        console.error(error);
      });
  }
});

下面是一个 sn-p，代码与您问题中的代码相似，以帮助突出问题：

// The following code will not work as expected
function simulateOnMessage(content) {
  console.log("================");
  const args = content.slice(17).trim().split(" ");
  console.log("Args: ", args);
  console.log("Args length: " + args.length);
  if (content === "!javaserverstatus") {
    console.log("Checking arguments...");
    if (!args.length) {
      return console.log("No server provided!");
    }
    if (args.length > 1) {
      return console.log("Bad input!");
    }
    console.log("No problems found!");
  }
  doSomethingWith(args.toString());
}
function doSomethingWith(str) {
  if (str === "") {
    console.log("EMPTY STRING!");
  } else {
    console.log("OK!");
  }
}
simulateOnMessage("!javaserverstatus");
simulateOnMessage("!javaserverstatus args");
simulateOnMessage("!javaserverstatus with args");
simulateOnMessage("completely invalid message");
simulateOnMessage("hi");

TLDR;

• 使用String.startsWith() 或类似的东西来检查您的命令是否正在运行
• 仅在符合条件的情况下运行代码