nyx/events/guildDelete.js

const client = require("../bot");
const db = require("../models/guilds");
const { prefix } = require("../config.json");
const { MessageEmbed } = require("discord.js");

client.on("guildDelete", async guild => {
  client.data.DelGuild(guild.id);
  client.ServerLog.send(
    new MessageEmbed()
      .setTitle("Deleted Server")
      .addField("Server Info", [
        `**>Server Name**: \n${guild.name}`,
        `**>Server ID**: \n${guild.id}`,
        `**>Server Member Count**: \n${guild.memberCount}`,
      ])
      .addField("Owner Info", [
        `**>Owner Tag**: \n${guild.owner.user.tag}`,
        `**>Owner ID**: \n${guild.owner.id}`,
      ])
      .setFooter(
        `${client.user.username} Currently in ${client.guilds.cache.size} servers`,
        client.user.displayAvatarURL()
      )
      .setTimestamp()
      .setThumbnail(guild.iconURL({ dynamic: true }))
      .setColor("RED")
  );
});

/**
 * @param {Client} client
 */
client.prefix = async function (message) {
  let custom;
  if (!message.guild) return;
  const data = await db
    .findOne({ Guild: message.guild.id })
    .catch(err => console.log(err));
  if (data) {
    custom = data.Prefix;
  } else {
    custom = prefix;
  }
  return custom;
};