Discord.js报DEP0018弃用警告及常量赋值错误问题求助

1 报错触发原因 #

• 核心语法错误：你用const声明了command变量，后续条件判断中错误使用赋值运算符=而非相等运算符===，试图给const常量重新赋值，直接触发TypeError: Assignment to constant variable报错。
• 异步错误未捕获：上述错误抛出在async修饰的message事件回调函数中，你没有添加try/catch块捕获异常，导致错误变成未处理的Promise拒绝，触发后续的弃用警告。
• 额外逻辑隐患：即便你把const改成let，单等号的赋值逻辑会让条件永远返回true，所有命令都会同时触发播放、暂停两段逻辑，功能完全无法正常运行。

2 调试思路与步骤 #

1. 优先读取报错核心信息：看到TypeError: Assignment to constant variable直接定位代码中所有const声明的变量，排查是否有重新赋值的操作。
2. 校验条件判断语法：区分赋值运算符=、宽松相等==、严格相等===的使用场景，所有判断变量值的条件都应该用===。
3. 补全异步错误捕获：所有async函数内部的逻辑都用try/catch包裹，避免未处理的Promise拒绝导致进程退出。
4. 逻辑验证：修复语法问题后，分别测试不同命令的执行结果，确认逻辑符合预期。

3 快速修复示例 #

关键代码修改点： #

1. 把条件判断的=改为===
2. 将DisTube的事件监听移到ready事件中，避免每次收到消息重复绑定监听
3. 给异步逻辑加try/catch块
4. 修复暂停逻辑中方法调用错误的问题

修改后的完整代码片段： #

const Discord = require("discord.js");
const client = new Discord.Client();
const DisTube = require("distube");
const distube = new DisTube(client, { searchSongs: false, emitNewSongOnly: true });
const prefix = "!";

// 队列状态模板抽离到全局，避免重复声明
const status = (queue) =>
    `Volume: \`${queue.volume}%\` | Filter: \`${queue.filter || "Off"}\` | Loop: \`${queue.repeatMode ? (queue.repeatMode == 2 ? "All Queue" : "This Song") : "Off"}\` | Autoplay: \`${queue.autoplay ? "On" : "Off"}\``;

client.on("ready", () => {
    console.log(`${client.user.tag} Está Online`);
    // DisTube事件监听只需要在启动时绑定一次
    distube
        .on("playSong", (message, queue, song) => message.channel.send(`Playing \`${song.name}\` - \`${song.formattedDuration}\`\nRequested by: ${song.user}\n${status(queue)}`))
        .on("addSong", (message, queue, song) => message.channel.send(`Added ${song.name} - \`${song.formattedDuration}\` to the queue by ${song.user}`))
        .on("playList", (message, queue, playlist, song) =>
            message.channel.send(`Play \`${playlist.name}\` playlist (${playlist.songs.length} songs).\nRequested by: ${song.user}\nNow playing \`${song.name}\` - \`${song.formattedDuration}\`\n${status(queue)}`)
        )
        .on("addList", (message, queue, playlist) => message.channel.send(`Added \`${playlist.name}\` playlist (${playlist.songs.length} songs) to queue\n${status(queue)}`))
        .on("searchResult", (message, result) => {
            let i = 0;
            message.channel.send(`**Choose an option from below**\n${result.map((song) => `**${++i}**. ${song.name} - \`${song.formattedDuration}\``).join("\n")}\n*Enter anything else or wait 60 seconds to cancel*`);
        })
        .on("searchCancel", (message) => message.channel.send(`Searching canceled`))
        .on("error", (message, e) => {
            console.error(e);
            message.channel.send("An error encountered: " + e);
        });
});

client.on("message", async (message) => {
    try {
        if (message.author.bot) return;
        if (!message.content.startsWith(prefix)) return;
        const args = message.content.slice(prefix.length).trim().split(/ +/g);
        const command = args.shift();

        if (command === "play") {
            if (!args[0]) return message.channel.send("Voce Precisa Falar Algo Para Eu Tocar");
            if (!message.member.voice.channel) return message.channel.send("Entre Em Um Canal De Voz Primeiro");
            distube.play(message, args.join(" "));
        }
        if (command === "pause") {
            const bot = message.guild.members.cache.get(client.user.id);
            if (!message.member.voice.channel) return message.channel.send("Entre Em Um Canal De Voz Primeiro");
            if (bot.voice.channel !== message.member.voice.channel) return message.channel.send("Você Não Está No Mesmo Canal De Voz!");
            distube.pause(message); 
            message.channel.send("Você Parou A Musica");
        }
    } catch (e) {
        console.error(e);
        message.channel.send("执行命令出错：" + e.message);
    }
});

client.login(process.env.TOKEN);

内容的提问来源于stack exchange，提问作者Joao Pedro Turra