feat(PartialGroupDMChannel): to support Invite#channel for group dms (#3786)

* add PartialGroupDMChannel class

* fix lint

* add new errors

* add new class to Channel.create

* fix lint

* update typings accordingly

* better implement errors

* remove unnecessary functions

* oops

* lint

* lint

* lint

* more lint

* more lint

* jsdoc typo

* suggested changes

* i did not forget the typings

src/errors/Messages.js

@@ -94,6 +94,9 @@ const Messages = {
   REACTION_RESOLVE_USER: 'Couldn\'t resolve the user ID to remove from the reaction.',
 
   VANITY_URL: 'This guild does not have the VANITY_URL feature enabled.',
+
+  DELETE_GROUP_DM_CHANNEL: 'Bots don\'t have access to Group DM Channels and cannot delete them',
+  FETCH_GROUP_DM_CHANNEL: 'Bots don\'t have access to Group DM Channels and cannot fetch them',
 };
 
 for (const [name, message] of Object.entries(Messages)) register(name, message);

src/structures/Channel.js

@@ -96,9 +96,19 @@ class Channel extends Base {
   static create(client, data, guild) {
     const Structures = require('../util/Structures');
     let channel;
-    if (data.type === ChannelTypes.DM || (data.type !== ChannelTypes.GROUP && !data.guild_id && !guild)) {
-      const DMChannel = Structures.get('DMChannel');
-      channel = new DMChannel(client, data);
+    if (!data.guild_id && !guild) {
+      switch (data.type) {
+        case ChannelTypes.DM: {
+          const DMChannel = Structures.get('DMChannel');
+          channel = new DMChannel(client, data);
+          break;
+        }
+        case ChannelTypes.GROUP: {
+          const PartialGroupDMChannel = require('./PartialGroupDMChannel');
+          channel = new PartialGroupDMChannel(client, data);
+          break;
+        }
+      }
     } else {
       guild = guild || client.guilds.cache.get(data.guild_id);
       if (guild) {

src/structures/PartialGroupDMChannel.js

@@ -0,0 +1,46 @@
+'use strict';
+
+const Channel = require('./Channel');
+const { Error } = require('../errors');
+
+/**
+ * Represents a Partial Group DM Channel on Discord.
+ * @extends {Channel}
+ */
+class PartialGroupDMChannel extends Channel {
+  constructor(client, data) {
+    super(client, data);
+
+    /**
+     * The name of this Group DM Channel
+     * @type {string}
+     */
+    this.name = data.name;
+
+    /**
+     * The hash of the channel icon
+     * @type {?string}
+     */
+    this.icon = data.icon;
+  }
+
+  /**
+   * The URL to this channel's icon.
+   * @param {ImageURLOptions} [options={}] Options for the Image URL
+   * @returns {?string}
+   */
+  iconURL({ format, size } = {}) {
+    if (!this.icon) return null;
+    return this.client.rest.cdn.GDMIcon(this.id, this.icon, format, size);
+  }
+
+  delete() {
+    return Promise.reject(new Error('DELETE_GROUP_DM_CHANNEL'));
+  }
+
+  fetch() {
+    return Promise.reject(new Error('FETCH_GROUP_DM_CHANNEL'));
+  }
+}
+
+module.exports = PartialGroupDMChannel;

typings/index.d.ts

@@ -840,6 +840,13 @@ declare module 'discord.js' {
 		public nsfw: boolean;
 	}
 
+	export class PartialGroupDMChannel extends Channel {
+		constructor(client: Client, data: object);
+		public name: string;
+		public icon: string | null;
+		public iconURL(options?: ImageURLOptions): string | null;
+	}
+
 	export class GuildEmoji extends Emoji {
 		constructor(client: Client, data: object, guild: Guild);
 		private _roles: string[];