This error wasn't a problem until today. Every time I would run my discordjs bot, it gives me a TypeError saying "Cannot read properties of undefined (reading 'toLowerCase')"

Heres my code

const { readdirSync } = require('fs');
const { Collection } = require('discord.js');



client.commands = new Collection();

const events = readdirSync('./events/').filter(file => file.endsWith('.js'));

console.log(`Loading events...`);

for (const file of events) {
    const event = require(`../events/${file}`);
    console.log(`-> Loaded event ${file.split('.')[0]}`);
    client.on(file.split('.')[0], event.bind(null, client));
    delete require.cache[require.resolve(`../events/${file}`)];
};

console.log(`Loading commands...`);

readdirSync('./commands/').forEach(dirs => {
    const commands = readdirSync(`./commands/${dirs}`).filter(files => files.endsWith('.js'));

    for (const file of commands) {
        const command = require(`../commands/${dirs}/${file}`);
        console.log(`-> Loaded command ${command.name.toLowerCase()}`);
        client.commands.set(command.name.toLowerCase(), command);
        delete require.cache[require.resolve(`../commands/${dirs}/${file}`)];
    };
});

when I run the bot, the output goes like this

Loading events...
-> Loaded event interactionCreate
-> Loaded event messageCreate
-> Loaded event ready
Loading commands...
TypeError: Cannot read properties of undefined (reading 'toLowerCase')
    at /home/runner/Saeki-Miyako-Bot/src/loader.js:26:55
    at Array.forEach (<anonymous>)
    at Object.<anonymous> (/home/runner/Saeki-Miyako-Bot/src/loader.js:21:28)
    at Module._compile (node:internal/modules/cjs/loader:1101:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1153:10)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)
    at Module.require (node:internal/modules/cjs/loader:1005:19)
    at require (node:internal/modules/cjs/helpers:102:18)
    at Object.<anonymous> (/home/runner/Saeki-Miyako-Bot/main.js:43:1)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! music-bot@12.22.6 start: `node main.js`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the music-bot@12.22.6 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /home/runner/.npm/_logs/2021-10-26T03_01_19_546Z-debug.log
exit status 1

CodePudding user response：

That means your commands (importing files) not all have the same structure (with property 'name') in it.

If the commands without name are not critical, you can filter out them:

for (const file of commands) {
  const command = require(`../commands/${dirs}/${file}`);
  if (!command || !command.name) {
    console.warn(`Name is missing in 'commands/${dirs}/${file}'`)
    continue;
  }

  console.log(`-> Loaded command ${command.name.toLowerCase()}`);
  client.commands.set(command.name.toLowerCase(), command);
  delete require.cache[require.resolve(`../commands/${dirs}/${file}`)];
};

Since I don't have an access to your file systems I can not see what content of the files is. But I assume the name is just missing in some of the file (command).