Discord.js Error: Cannot read property 'then' of undefined

Question

I'm making a mute command for my discord bot and currently I'm get an error;

TypeError: Cannot read property 'then' of undefined

I do not know what exactly is causing this issue and would like to know if there are more errors with this code or not

const BaseCommand = require('../../utils/structures/BaseCommand');
const Discord = require('discord.js');

module.exports = class MuteCommand extends BaseCommand {
  constructor() {
    super('mute', 'moderation', []);
  }

  async run(client, message, args) {
    if(!message.member.hasPermission("MUTE_MEMBERS")) return message.channel.send("You do not have Permission to use this command.");
    if(!message.guild.me.hasPermission("MUTE_MEMBERS")) return message.channel.send("I do not have Permissions to mute members.");
    const Embedhelp = new Discord.MessageEmbed()
    .setTitle('Mute Command')
    .setColor('#6DCE75')
    .setDescription('Use this command to Mute a member so that they cannot chat in text channels nor speak in voice channels')
    .addFields(
      { name: '**Usage:**', value: '=mute (user) (time) (reason)'},
      { name: '**Example:**', value: '=mute @Michael stfu'},
      { name: '**Info**', value: 'You cannot mute yourself.\nYou cannot mute me.\nYou cannot mute members with a role higher than yours\nYou cannot mute members that have already been muted'}
   )
    .setFooter(client.user.tag, client.user.displayAvatarURL());

    let role = 'Muted'
    let newrole = message.guild.roles.cache.find(x => x.name === role);
    if (typeof newrole === undefined) {
      message.guild.roles.create({
        data: {
          name: 'muted',
          color: '#ff0000',
          permissions: {
              SEND_MESSAGES: false,
              ADD_REACTIONS: false,
              SPEAK: false
          }
        },
        reason: 'to mute people',
      })
      .catch(console.log(err)); {
        message.channel.send('Could not create muted role');
      }
    } 
    let muterole = message.guild.roles.cache.find(x => x.name === role);

    const mentionedMember = message.mentions.members.first() || await message.guild.members.fetch(args[0]);
    let reason = args.slice(1).join(" ");
    const banEmbed = new Discord.MessageEmbed()
     .setTitle('You have been Muted in '+message.guild.name)
     .setDescription('Reason for Mute: '+reason)
     .setColor('#6DCE75')
     .setTimestamp()
     .setFooter(client.user.tag, client.user.displayAvatarURL());

   if (!reason) reason = 'No reason provided';
   if (!args[0]) return message.channel.send(Embedhelp);
   if (!mentionedMember) return message.channel.send(Embedhelp);
   if (!mentionedMember.bannable) return message.channel.send(Embedhelp);
   if (mentionedMember.user.id == message.author.id) return message.channel.send(Embedhelp);
   if (mentionedMember.user.id == client.user.id) return message.channel.send(Embedhelp);
   if (mentionedMember.roles.cache.has(muterole)) return message.channel.send(Embedhelp);
   if (message.member.roles.highest.position <= mentionedMember.roles.highest.position) return message.channel.send(Embedhelp);

   await mentionedMember.send(banEmbed).catch(err => console.log(err));
   await mentionedMember.roles.add(muterole).catch(err => console.log(err).then(message.channel.send('There was an error while muting the member')))

  } 
}

My guess is that the error has something to do with the last line of code, I'm not sure if this code has more errors is in it but I would very much like to know and am also open to any suggestions with improving the code itself.

Answer 1

You are putting then() in the wrong spot. You would execute then() against add(muterole) (which returns a promise) or you could apply it to catch() or within catch() , but you are applying it to console.log() which doesn't return anything nor is a Promise . Try the following:

await mentionedMember.roles
  .add(muterole)
  .then()
  .catch((err) => {
    console.log(err);
    // You are trying to send an error message when an error occurs?
    return message.channel.send("There was an error while muting the member")
  });

or

await mentionedMember.roles
  .add(muterole)
  .catch((err) => console.log(err))
  .then(() =>
    message.channel.send("There was an error while muting the member")
  );

Hopefully that helps!