How to make Text to speech queue Node.js

Question

This might be a very simple thing to do for the pros like some of you, I hope you can help me, I will really appreciate your time, thanks.

I have this TTS discord bot, and it works! But I can't figure out how to queue extra incoming TTS requests.

When current TTS is playing and a new request is submitted, current TTS will stop and start executing next request without letting the current TTS finish.

What I want to do is queue all requests so every single one plays after each finishes.

Some one told me to use this package but I just can't figure it out.

I'm a noob with very limited knowledge, so can someone please add the extra lines that are needed for queues? Or provide a good guide?

I'm sorry for being too picky I know I shouldn't ask for too much, but I've been dealing with this issue for weeks now and I'm desperate.

Here is my code:

const { getAudioUrl } = require('google-tts-api');

module.exports = {
  name: 'say',
  aliases: ['s'],
  cooldown: 3,
  description: "tts",

  execute: async (message, args, cmd, client, Discord) => {
    console.log('Say command executed');

    if (!args[0]) 
      return message.channel.send('you gotta include a message!');
    
    const string = args.join(' ');

    if (string.length > 200) 
      return message.channel.send('the message cant be more than 200 letters!');
    
    const voiceChannel = message.member.voice.channel;

    if (!voiceChannel) 
      return message.reply('You have to be in a voice channel to send a message!');

    const audioURL = getAudioUrl(string, {
      lang: 'en',
      slow: false,
      host: 'https://translate.google.com',
      timeout: 10000,
    });

    try {
      message.channel.startTyping();

      setTimeout(function () {
        message.channel.send('Speaking your msg...');
        message.channel.stopTyping();
        console.log('Now starting to talk');
      }, 1000);

      voiceChannel.join().then(connection => {
        const dispatcher = connection.play(audioURL);
        dispatcher.on('finish', () => {
          console.log('Done talking');
        });
      });
    }
    catch (e) {
      message.channel.send('Bot error, please try again or try later');
      console.error(e);
    }

    setTimeout(function () {
      voiceChannel.leave();
    }, 240000);
  }
}

Answer 1

With queue package you "push" your execute logic wrapped in a function. The function will be then executed by the queue. The tricky part here is that you need to end the execution inside the dispatcher's finish event handler. You can introduce a new promise which will be then resolved from inside the event handler.

Here's a rough sketch of the solution:

const { getAudioUrl } = require('google-tts-api');
const queue = require('queue');

// Create the queue where we will push our jobs
const q = queue({ concurrency: 1, autostart: true });

module.exports = {
  name: 'say',
  aliases: ['s'],
  cooldown: 3,
  description: 'tts',

  execute: (message, args, cmd, client, Discord) => {
    // Enqueue task
    q.push(async () => {
      console.log('Say command executed');

      if (!args[0]) {
        return message.channel.send('you gotta include a message!');
      }

      const string = args.join(' ');

      if (string.length > 200) {
        return message.channel.send(
          'the message cant be more than 200 letters!'
        );
      }

      const voiceChannel = message.member.voice.channel;

      if (!voiceChannel) {
        return message.reply(
          'You have to be in a voice channel to send a message!'
        );
      }

      const audioURL = getAudioUrl(string, {
        lang: 'en',
        slow: false,
        host: 'https://translate.google.com',
        timeout: 10000,
      });

      try {
        message.channel.startTyping();

        setTimeout(function () {
          message.channel.send('Speaking your msg...');
          message.channel.stopTyping();
          console.log('Now starting to talk');
        }, 1000);

        const connection = await voiceChannel.join();
        const dispatcher = connection.play(audioURL);
        // Here we need to handle the promise resolution from the nested event handler
        return Promise.new((resolve, reject) => {
          dispatcher.on('finish', () => {
            console.log('Done talking');
            // voiceChannel.leave();
            resolve();
          });
          dispatcher.on('error', (err) => {
            console.log('Some error in dispatcher happenned!', err);
            reject(err);
          });
        });
      } catch (e) {
        message.channel.send('Bot error, please try again or try later');
        console.error(e);
      }

      // This code won't be called
      setTimeout(function () {
        voiceChannel.leave();
      }, 240000);
    });
  },
};

Take this solution with a grain of salt. I didn't figure out what version of Discord.js you are targeting. Also note that timeouts and possible other error conditions are not handled.