Discord bot for YouTube throws UnhandledPromiseRejection error

Other Questions Discord bot
1

I’m having trouble with my YouTube Discord bot. It keeps throwing an UnhandledPromiseRejection error. The full error message looks like this:

UnhandledPromiseRejection: This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). The promise rejected with the reason "#<Object>".
at throwUnhandledRejectionsMode (node:internal/process/promises:392:7)
at processPromiseRejections (node:internal/process/promises:475:17)
at process.processTicksAndRejections (node:internal/process/task_queues:106:32) {
  code: 'ERR_UNHANDLED_REJECTION'

I got the code from GitHub, but the repo isn’t active anymore. Here’s a simplified version of what I’m working with:

const Discord = require('discord.js');
const RSSParser = require('rss-parser');
const YouTubeAPI = require('youtube-api-v3');

const client = new Discord.Client();
const parser = new RSSParser();
const youtube = new YouTubeAPI(config.youtubeApiKey);

client.login(config.botToken);

client.on('ready', () => {
  console.log('Bot is ready!');
  checkYouTubers();
  setInterval(checkYouTubers, 30000);
});

async function checkYouTubers() {
  for (const channel of config.youtubeChannels) {
    const latestVideo = await getLatestVideo(channel);
    if (latestVideo && isNewVideo(latestVideo)) {
      notifyDiscord(latestVideo);
    }
  }
}

// Other functions like getLatestVideo, isNewVideo, and notifyDiscord are implemented here

Can anyone help me figure out what’s causing this error and how to fix it?

2

yo, ive seen this before. its prolly cuz ur not handlin errors right in ur async stuff. try addin some try-catch blocks in ur functions, especially that checkYouTubers one. also make sure ur getLatestVideo and notifyDiscord funcs have error handling too. that should fix the unhandledpromiserejection thing

3

I’ve encountered similar issues with UnhandledPromiseRejection errors in Discord bots. The problem likely stems from not properly handling errors in your async functions. To resolve this, wrap the contents of your checkYouTubers function in a try-catch block. This will catch any errors that occur during execution and prevent them from becoming unhandled rejections.

Here’s how you could modify your checkYouTubers function:

async function checkYouTubers() {
  try {
    for (const channel of config.youtubeChannels) {
      const latestVideo = await getLatestVideo(channel);
      if (latestVideo && isNewVideo(latestVideo)) {
        await notifyDiscord(latestVideo);
      }
    }
  } catch (error) {
    console.error('Error in checkYouTubers:', error);
  }
}

Also, ensure that your getLatestVideo and notifyDiscord functions have proper error handling. This approach should resolve the UnhandledPromiseRejection error and make your bot more robust.

4

I’ve dealt with similar issues in my YouTube Discord bot projects. One thing that helped me was implementing a more robust error handling strategy. Instead of just wrapping the main function in a try-catch, I found it beneficial to add error handling to each individual API call.

For example, in your getLatestVideo function, you might want to add something like:

async function getLatestVideo(channel) {
  try {
    const feed = await parser.parseURL(`https://www.youtube.com/feeds/videos.xml?channel_id=${channel}`);
    return feed.items[0];
  } catch (error) {
    console.error(`Error fetching latest video for channel ${channel}:`, error);
    return null;
  }
}

This way, if one channel fails, it won’t break the entire loop. You can also add some logging to help diagnose which specific channels or API calls are causing issues. It’s made my bot much more stable and easier to debug when problems do occur.