discord.js commando运行感谢命令时报Invalid left-hand side in assignment错误

核心错误根源 #

你遇到的ReferenceError: Invalid left-hand side in assignment错误完全由语法错误导致：

• 计算时间差的代码行错误使用了赋值运算符：

// 错误写法
const diff = now.getTime() = then.getTime()

你本意是计算两个时间戳的差值，应该用减法运算符-，这里连续使用=会被解析为要把then.getTime()的结果赋值给now.getTime()的返回值，而函数返回值是不可被赋值的左值，因此直接抛出该错误。

其他需要修正的隐性错误 #

你粘贴的代码里还有几个转义和拼写问题，需要同步修正才能正常运行：

1. 代码中的逻辑与运算符被转义为&&，需要改回原生&&
2. 小于等于运算符被转义为<=，需要改回原生<=
3. 成功消息的描述文本中<@${targetId}缺少闭合的>符号，会导致用户提及渲染异常

修正后的完整命令代码 #

const Commando = require('discord.js-commando')
const Discord = require('discord.js')
const thanksSchema = require('@schemas/thanks-schema')

module.exports = class ThanksCommand extends Commando.Command {
    constructor(client) {
        super(client, {
            name: 'thanks',
            group: 'thanks',
            memberName: 'thanks',
            description: 'Thanks a staff member for their help',
        })
    }

    async run(message) {
        const target = message.mentions.users.first()
        if (!target) {
            const noPingThanksEmbed = new Discord.MessageEmbed()
            .setTitle('ERROR: Invalid user provided')
            .setDescription('Please tag a valid user')
            .setColor('#ff0000')
            message.channel.send(noPingThanksEmbed)
            return
        }

        const { guild } = message
        const guildId = guild.id
        const targetId = target.id
        const authorId = message.author.id
        const now = new Date()

        if (targetId === authorId) {
            const thankSelfEmbed = new Discord.MessageEmbed()
            .setTitle('ERROR: Invalid user provided')
            .setDescription('You cannot thank yourself')
            .setFooter('LOL YOU THOUGHT')
            .setColor('#ff0000')
            message.channel.send(thankSelfEmbed)
            return
        }

        const authorData = await thanksSchema.findOne({
            userId: authorId,
            guildId,
        })

        if (authorData && authorData.lastGave) {
            const then = new Date(authorData.lastGave)

            const diff = now.getTime() - then.getTime()
            const diffHours = Math.round(diff / (1000 * 60 * 60))
            const hours = 24

            if (diffHours <= hours) {
                const cooldownThankEmbed = new Discord.MessageEmbed()
                .setTitle('ERROR: User on cooldown')
                .setDescription(`You have already thanked someone within the last ${hours} hours`)
                .setColor('#ff0000')
                message.channel.send(cooldownThankEmbed)
                return
            }
        }

        await thanksSchema.findOneAndUpdate({
            userId: authorId,
            guildId,
        }, {
            userId: authorId,
            guildId,
            lastGave: now,
        }, {
            upsert: true,
        })

        const result = await thanksSchema.findOneAndUpdate({
            userId: targetId,
            guildId,
        }, {
            userId: targetId,
            guildId,
            $inc: {
                received: 1,
            }
        }, {
            upsert: true,
            new: true,
        })

        const amount = result.received

        const thanksEmbed = new Discord.MessageEmbed()
        .setTitle('SUCCESS')
        .setDescription(`<@${authorId}> has thanked <@${targetId}>!

They now have ${amount} thanks`)
        .setColor('#1be730')
        message.channel.send(thanksEmbed)
    }
}

补充说明 #

Discord.js Commando框架会默认捕获命令执行时的运行时错误，不会将错误抛出到全局服务端控制台，因此你看不到控制台报错，只有命令执行流程被中断，修改后重启机器人即可正常使用该命令。

内容的提问来源于stack exchange，提问作者PrezOfTheUnitedIdiots