feat(ThreadChannel): Backport creation timestamp

src/structures/ThreadChannel.js

@@ -100,6 +100,11 @@ class ThreadChannel extends Channel {
        * @type {?number}
        */
       this.archiveTimestamp = new Date(data.thread_metadata.archive_timestamp).getTime();
+
+      if ('create_timestamp' in data.thread_metadata) {
+        // Note: this is needed because we can't assign directly to getters
+        this._createdTimestamp = Date.parse(data.thread_metadata.create_timestamp);
+      }
     } else {
       this.locked ??= null;
       this.archived ??= null;
@@ -108,6 +113,8 @@ class ThreadChannel extends Channel {
       this.invitable ??= null;
     }
 
+    this._createdTimestamp ??= this.type === 'GUILD_PRIVATE_THREAD' ? super.createdTimestamp : null;
+
     if ('owner_id' in data) {
       /**
        * The id of the member who created this thread
@@ -176,6 +183,16 @@ class ThreadChannel extends Channel {
     if (data.messages) for (const message of data.messages) this.messages._add(message);
   }
 
+  /**
+   * The timestamp when this thread was created. This isn't available for threads
+   * created before 2022-01-09
+   * @type {?number}
+   * @readonly
+   */
+  get createdTimestamp() {
+    return this._createdTimestamp;
+  }
+
   /**
    * A collection of associated guild member objects of this thread's members
    * @type {Collection<Snowflake, GuildMember>}
@@ -196,6 +213,15 @@ class ThreadChannel extends Channel {
     return new Date(this.archiveTimestamp);
   }
 
+  /**
+   * The time the thread was created at
+   * @type {?Date}
+   * @readonly
+   */
+  get createdAt() {
+    return this.createdTimestamp && new Date(this.createdTimestamp);
+  }
+
   /**
    * The parent channel of this thread
    * @type {?(NewsChannel|TextChannel)}
@@ -490,6 +516,14 @@ class ThreadChannel extends Channel {
     return this.archived && (this.locked ? this.manageable : this.sendable);
   }
 
+  /**
+   * Whether this thread is a private thread
+   * @returns {boolean}
+   */
+  isPrivate() {
+    return this.type === 'GUILD_PRIVATE_THREAD';
+  }
+
   /**
    * Deletes this thread.
    * @param {string} [reason] Reason for deleting this thread

typings/index.d.ts

@@ -516,8 +516,8 @@ export type CategoryChannelResolvable = Snowflake | CategoryChannel;
 
 export abstract class Channel extends Base {
   public constructor(client: Client, data?: RawChannelData, immediatePatch?: boolean);
-  public readonly createdAt: Date;
-  public readonly createdTimestamp: number;
+  public readonly createdAt: Date | null;
+  public readonly createdTimestamp: number | null;
   /** @deprecated This will be removed in the next major version, see https://github.com/discordjs/discord.js/issues/7091 */
   public deleted: boolean;
   public id: Snowflake;
@@ -1042,7 +1042,8 @@ export abstract class GuildChannel extends Channel {
   public constructor(guild: Guild, data?: RawGuildChannelData, client?: Client, immediatePatch?: boolean);
   private memberPermissions(member: GuildMember, checkAdmin: boolean): Readonly<Permissions>;
   private rolePermissions(role: Role, checkAdmin: boolean): Readonly<Permissions>;
-
+  public readonly createdAt: Date;
+  public readonly createdTimestamp: number;
   public readonly calculatedPosition: number;
   public readonly deletable: boolean;
   public guild: Guild;
@@ -2304,6 +2305,9 @@ export class ThreadChannel extends TextBasedChannelMixin(Channel) {
   public archived: boolean | null;
   public readonly archivedAt: Date | null;
   public archiveTimestamp: number | null;
+  public readonly createdAt: Date | null;
+  private _createdTimestamp: number | null;
+  public readonly createdTimestamp: number | null;
   public autoArchiveDuration: ThreadAutoArchiveDuration | null;
   public readonly editable: boolean;
   public guild: Guild;
@@ -2327,6 +2331,11 @@ export class ThreadChannel extends TextBasedChannelMixin(Channel) {
   public rateLimitPerUser: number | null;
   public type: ThreadChannelTypes;
   public readonly unarchivable: boolean;
+  public isPrivate(): this is this & {
+    readonly createdTimestamp: number;
+    readonly createdAt: Date;
+    type: 'GUILD_PRIVATE_THREAD';
+  };
   public delete(reason?: string): Promise<this>;
   public edit(data: ThreadEditData, reason?: string): Promise<ThreadChannel>;
   public join(): Promise<ThreadChannel>;