feat(ThreadMemberManager): allow individual members to be fetched

src/managers/ThreadMemberManager.js

@@ -92,17 +92,38 @@ class ThreadMemberManager extends CachedManager {
     return id;
   }
 
+  async _fetchId(memberId, cache, force) {
+    if (!force) {
+      const existing = this.cache.get(memberId);
+      if (existing) return existing;
+    }
+
+    const data = await this.client.api.channels(this.thread.id, 'thread-members', memberId).get();
+    return this._add(data, cache);
+  }
+
+  async _fetchMany(cache) {
+    const raw = await this.client.api.channels(this.thread.id, 'thread-members').get();
+    return raw.reduce((col, member) => col.set(member.id, this._add(member, cache)), new Collection());
+  }
+
   /**
    * Fetches member(s) for the thread from Discord, requires access to the `GUILD_MEMBERS` gateway intent.
-   * @param {boolean} [cache=true] Whether or not to cache the fetched members
-   * @returns {Promise<Collection<Snowflake, ThreadMember>>}
+   * @param {UserResolvable|boolean} [member] The member to fetch. If `undefined`, all members
+   * in the thread are fetched, and will be cached based on `options.cache`. If boolean, this serves
+   * the purpose of `options.cache`.
+   * @param {BaseFetchOptions} [options] Additional options for this fetch
+   * @returns {Promise<ThreadMember|Collection<Snowflake, ThreadMember>>}
    */
-  async fetch(cache = true) {
-    const raw = await this.client.api.channels(this.thread.id, 'thread-members').get();
-    return raw.reduce((col, rawMember) => {
-      const member = this._add(rawMember, cache);
-      return col.set(member.id, member);
-    }, new Collection());
+  fetch(member, { cache = true, force = false } = {}) {
+    // TODO: Replace `member` usages as `cache` with correct respective parameter.
+    if (typeof member === 'string') {
+      return this._fetchId(member, cache, force);
+    } else if (member && typeof member === 'object') {
+      return this._fetchId(member.id, cache, force);
+    }
+
+    return this._fetchMany(member ?? cache);
   }
 }
 

typings/index.d.ts

@@ -2897,6 +2897,8 @@ export class ThreadMemberManager extends CachedManager<Snowflake, ThreadMember,
   private constructor(thread: ThreadChannel, iterable?: Iterable<RawThreadMemberData>);
   public thread: ThreadChannel;
   public add(member: UserResolvable | '@me', reason?: string): Promise<Snowflake>;
+  public fetch(member?: UserResolvable, options?: BaseFetchOptions): Promise<ThreadMember>;
+  /** @deprecated Use `fetch(member, options)` instead. */
   public fetch(cache?: boolean): Promise<Collection<Snowflake, ThreadMember>>;
   public remove(id: Snowflake | '@me', reason?: string): Promise<Snowflake>;
 }

typings/tests.ts

@@ -70,6 +70,7 @@ import {
   TextBasedChannels,
   TextChannel,
   ThreadChannel,
+  ThreadMember,
   Typing,
   User,
   VoiceChannel,
@@ -434,10 +435,17 @@ client.on('ready', async () => {
 // This is to check that stuff is the right type
 declare const assertIsPromiseMember: (m: Promise<GuildMember>) => void;
 
-client.on('guildCreate', g => {
+client.on('guildCreate', async g => {
   const channel = g.channels.cache.random();
   if (!channel) return;
 
+  if (channel.isThread()) {
+    const fetchedMember = await channel.members.fetch('12345678');
+    assertType<ThreadMember>(fetchedMember);
+    const fetchedMemberCol = await channel.members.fetch(true);
+    assertType<Collection<Snowflake, ThreadMember>>(fetchedMemberCol);
+  }
+
   channel.setName('foo').then(updatedChannel => {
     console.log(`New channel name: ${updatedChannel.name}`);
   });