Discord.js执行/ping命令时出现TypeError错误，请求排查问题

错误原因 #

你代码里的核心问题是获取用户的方式错误：Discord.js的斜杠命令交互对象（ChatInputCommandInteraction）没有author属性，你用interaction.author获取用户时，得到的是undefined，自然无法读取username字段，进而抛出错误。

斜杠命令场景下，要获取发起命令的用户，必须使用interaction.user属性，这是交互对象对应的用户入口。

修复后的代码 #

把const user = interaction.author;替换为const user = interaction.user;即可，修复后的完整代码如下：

const TOKEN = "mybotstoken";
const CLIENT_ID = "mybotsclientid";

const { REST, Routes } = require('discord.js');

const commands = [
  {
    name: 'ping',
    description: 'Replies with Pong!',
  },
];

const rest = new REST({ version: '10' }).setToken(TOKEN);

(async () => {
  try {
    console.log('Started refreshing application (/) commands.');

    await rest.put(Routes.applicationCommands(CLIENT_ID), { body: commands });

    console.log('Successfully reloaded application (/) commands.');
  } catch (error) {
    console.error(error);
  }
})();

const { Client, GatewayIntentBits } = require('discord.js');
const client = new Client({ intents: [GatewayIntentBits.Guilds] });

client.on('ready', () => {
  console.log(`Logged in as ${client.user.tag}!`);
});

client.on('interactionCreate', async interaction => {
  if (!interaction.isChatInputCommand()) return;

  if (interaction.commandName === 'ping') {
    const user = interaction.user; // 修复的核心位置

    const username = user.username;
    console.log(`Got a ping execute request from: ${username}`);

    await interaction.reply('Pong!');
    console.log(`Execute successful`); // 顺便修正拼写错误：succesful → successful
  }
});

client.login(TOKEN);

额外说明 #

• interaction.author仅存在于普通消息对象（Message）中，斜杠命令属于交互体系，必须用interaction.user获取发起用户。
• 顺便修正了代码里的拼写错误，将succesful改为successful，避免日志出现拼写问题。

内容的提问来源于stack exchange，提问作者Guli