feat: add typeguards to webhooks

src/structures/Webhook.js

@@ -395,6 +395,22 @@ class Webhook {
     return this.client.rest.cdn.Avatar(this.id, this.avatar, format, size);
   }
 
+  /**
+   * Whether or not this webhook is a channel follower webhook.
+   * @returns {boolean}
+   */
+  isChannelFollower() {
+    return this.type === WebhookTypes['Channel Follower'];
+  }
+
+  /**
+   * Whether or not this webhook is an incoming webhook.
+   * @returns {boolean}
+   */
+  isIncoming() {
+    return this.type === WebhookTypes.Incoming;
+  }
+
   static applyToClass(structure, ignore = []) {
     for (const prop of [
       'send',

typings/index.d.ts

@@ -2204,6 +2204,11 @@ export class Webhook extends WebhookMixin() {
   public sourceChannel: NewsChannel | APIPartialChannel | null;
   public token: string | null;
   public type: WebhookType;
+  public isIncoming(): this is this & { token: string };
+  public isChannelFollower(): this is this & {
+    sourceGuild: Guild | APIPartialGuild;
+    sourceChannel: NewsChannel | APIPartialChannel;
+  };
 }
 
 export class WebhookClient extends WebhookMixin(BaseClient) {