discord.js/src/client/ClientDataManager.js

const Constants = require('../util/Constants');
const Util = require('../util/Util');
const Guild = require('../structures/Guild');
const User = require('../structures/User');
const Channel = require('../structures/Channel');
const GuildChannel = require('../structures/GuildChannel');
const Emoji = require('../structures/Emoji');

class ClientDataManager {
  constructor(client) {
    this.client = client;
  }

  get pastReady() {
    return this.client.ws.connection.status === Constants.Status.READY;
  }

  newGuild(data) {
    const already = this.client.guilds.has(data.id);
    const guild = new Guild(this.client, data);
    this.client.guilds.set(guild.id, guild);
    if (!this.client.user.bot && this.client.options.sync) this.client.syncGuilds([guild]);
    if (this.pastReady && !already) {
      /**
       * Emitted whenever the client joins a guild.
       * @event Client#guildCreate
       * @param {Guild} guild The created guild
       */
      if (this.client.options.fetchAllMembers) {
        guild.fetchMembers().then(() => { this.client.emit(Constants.Events.GUILD_CREATE, guild); });
      } else {
        this.client.emit(Constants.Events.GUILD_CREATE, guild);
      }
    }

    return guild;
  }

  newUser(data) {
    if (this.client.users.has(data.id)) return this.client.users.get(data.id);
    const user = new User(this.client, data);
    this.client.users.set(user.id, user);
    return user;
  }

  newChannel(data, guild) {
    const already = this.client.channels.has(data.id);
    const channel = Channel.create(this.client, data, guild);

    if (channel) {
      if (this.pastReady && !already) this.client.emit(Constants.Events.CHANNEL_CREATE, channel);
      this.client.channels.set(channel.id, channel);
      return channel;
    }

    return null;
  }

  newEmoji(data, guild) {
    const already = guild.emojis.has(data.id);
    if (data && !already) {
      let emoji = new Emoji(guild, data);
      this.client.emit(Constants.Events.GUILD_EMOJI_CREATE, emoji);
      guild.emojis.set(emoji.id, emoji);
      return emoji;
    } else if (already) {
      return guild.emojis.get(data.id);
    }

    return null;
  }

  killEmoji(emoji) {
    if (!(emoji instanceof Emoji && emoji.guild)) return;
    this.client.emit(Constants.Events.GUILD_EMOJI_DELETE, emoji);
    emoji.guild.emojis.delete(emoji.id);
  }

  killGuild(guild) {
    const already = this.client.guilds.has(guild.id);
    this.client.guilds.delete(guild.id);
    if (already && this.pastReady) this.client.emit(Constants.Events.GUILD_DELETE, guild);
  }

  killUser(user) {
    this.client.users.delete(user.id);
  }

  killChannel(channel) {
    this.client.channels.delete(channel.id);
    if (channel instanceof GuildChannel) channel.guild.channels.delete(channel.id);
  }

  updateGuild(currentGuild, newData) {
    const oldGuild = Util.cloneObject(currentGuild);
    currentGuild.setup(newData);
    if (this.pastReady) this.client.emit(Constants.Events.GUILD_UPDATE, oldGuild, currentGuild);
  }

  updateChannel(currentChannel, newData) {
    currentChannel.setup(newData);
  }

  updateEmoji(currentEmoji, newData) {
    const oldEmoji = Util.cloneObject(currentEmoji);
    currentEmoji.setup(newData);
    this.client.emit(Constants.Events.GUILD_EMOJI_UPDATE, oldEmoji, currentEmoji);
    return currentEmoji;
  }
}

module.exports = ClientDataManager;