Expose welcomeScreen on Invite (#1037)

Author: Khaaz

index.d.ts

@@ -634,6 +634,16 @@ declare namespace Eris {
     computePruneCount?: boolean;
     reason?: string;
   }
+  interface WelcomeChannel {
+    channelID: string;
+    description: string;
+    emojiID: string | null;
+    emojiName: string | null;
+  }
+  interface WelcomeScreen {
+    description: string;
+    welcomeChannels: WelcomeChannel[];
+  }
   interface VoiceRegion {
     custom: boolean;
     deprecated: boolean;
@@ -1197,7 +1207,6 @@ declare namespace Eris {
     theme: string;
   }
 
-
   class Base implements SimpleJSON {
     createdAt: number;
     id: string;
@@ -1783,8 +1792,10 @@ declare namespace Eris {
     vanityURL: string | null;
     verificationLevel: number;
     voiceStates: Collection<VoiceState>;
+    welcomeScreen?: WelcomeScreen;
     widgetChannelID?: string | null;
     widgetEnabled?: boolean | null;
+
     constructor(data: BaseData, client: Client);
     addDiscoverySubcategory(categoryID: string, reason?: string): Promise<DiscoverySubcategoryResponse>;
     addMemberRole(memberID: string, roleID: string, reason?: string): Promise<void>;

lib/structures/Guild.js

@@ -64,6 +64,9 @@ const {Permissions} = require("../Constants");
 * @prop {String?} vanityURL The vanity URL of the guild (VIP only)
 * @prop {Number} verificationLevel The guild verification level
 * @prop {Collection<VoiceState>} voiceStates Collection of voice states in the guild
+* @prop {Object?} welcomeScreen The welcome screen of a Community guild, shown to new members
+* @prop {Object} welcomeScreen.description The description in the welcome screen
+* @prop {Array<Object>} welcomeScreen.welcomeChannels The list of channels in the welcome screens. Each channels have the following properties: `channelID`, `description`, `emojiID`, `emojiName`. `emojiID` and `emojiName` properties can be null.
 * @prop {Number?} widgetChannelID The channel id that the widget will generate an invite to. REST only.
 * @prop {Boolean?} widgetEnabled Whether the guild widget is enabled. REST only.
 */
@@ -261,6 +264,19 @@ class Guild extends Base {
         if(data.max_video_channel_users !== undefined) {
             this.maxVideoChannelUsers = data.max_video_channel_users;
         }
+        if(data.guild.welcome_screen !== undefined) {
+            this.welcomeScreen = {
+                description: data.guild.welcome_screen.description,
+                welcomeChannels: data.guild.welcome_screen.welcome_channels && data.guild.welcome_screen.welcome_channels.map((c) => {
+                    return {
+                        channelID: c.channel,
+                        description: c.description,
+                        emojiID: c.emoji_id,
+                        emojiName: c.emoji_name
+                    };
+                })
+            };
+        }
     }
 
     get bannerURL() {