feat(Webhook): add type property and created* getters (#3585)

* feat(Webhook): add created* getters

* feat(Webhook): add type property

* typings(WebhookFields): use primitive string for url getter

Co-Authored-By: Gryffon Bellish <owenbellish@gmail.com>

* fix(Webhook): token can be null

Co-authored-by: Gryffon Bellish <owenbellish@gmail.com>

src/structures/Webhook.js

@@ -1,6 +1,8 @@
 'use strict';
 
+const { WebhookTypes } = require('../util/Constants');
 const DataResolver = require('../util/DataResolver');
+const Snowflake = require('../util/Snowflake');
 const Channel = require('./Channel');
 const APIMessage = require('./APIMessage');
 
@@ -29,9 +31,9 @@ class Webhook {
     /**
      * The token for the webhook
      * @name Webhook#token
-     * @type {string}
+     * @type {?string}
      */
-    Object.defineProperty(this, 'token', { value: data.token, writable: true, configurable: true });
+    Object.defineProperty(this, 'token', { value: data.token || null, writable: true, configurable: true });
 
     /**
      * The avatar for the webhook
@@ -45,6 +47,12 @@ class Webhook {
      */
     this.id = data.id;
 
+    /**
+     * The type of the webhook
+     * @type {WebhookTypes}
+     */
+    this.type = WebhookTypes[data.type];
+
     /**
      * The guild the webhook belongs to
      * @type {Snowflake}
@@ -210,6 +218,23 @@ class Webhook {
   delete(reason) {
     return this.client.api.webhooks(this.id, this.token).delete({ reason });
   }
+  /**
+   * The timestamp the webhook was created at
+   * @type {number}
+   * @readonly
+   */
+  get createdTimestamp() {
+    return Snowflake.deconstruct(this.id).timestamp;
+  }
+
+  /**
+   * The time the webhook was created at
+   * @type {Date}
+   * @readonly
+   */
+  get createdAt() {
+    return new Date(this.createdTimestamp);
+  }
 
   /**
    * The url of this webhook
@@ -236,6 +261,9 @@ class Webhook {
       'sendSlackMessage',
       'edit',
       'delete',
+      'createdTimestamp',
+      'createdAt',
+      'url',
     ]) {
       Object.defineProperty(structure.prototype, prop,
         Object.getOwnPropertyDescriptor(Webhook.prototype, prop));