feat(DMChannel): allow partial DMChannel without client user

packages/discord.js/src/client/actions/Action.js

@@ -33,10 +33,15 @@ class Action {
     const payloadData = {};
     const id = data.channel_id ?? data.id;
 
-    if (!('recipients' in data)) {
-      // Try to resolve the recipient, but do not add the client user.
+    if ('recipients' in data) {
+      // Try to resolve the recipient, but do not add if already existing in recipients.
       const recipient = data.author ?? data.user ?? { id: data.user_id };
-      if (recipient.id !== this.client.user.id) payloadData.recipients = [recipient];
+      if (data.recipients.every(existingRecipient => recipient.id !== existingRecipient.id))
+        payloadData.recipients = [...data.recipients, recipient];
+    } else {
+      // Try to resolve the recipient.
+      const recipient = data.author ?? data.user ?? { id: data.user_id };
+      payloadData.recipients = [recipient];
     }
 
     if (id !== undefined) payloadData.id = id;

packages/discord.js/src/client/actions/InteractionCreate.js

@@ -21,7 +21,9 @@ class InteractionCreateAction extends Action {
     const client = this.client;
 
     // Resolve and cache partial channels for Interaction#channel getter
-    const channel = data.channel && this.getChannel(data.channel);
+    const channel =
+      data.channel &&
+      this.getChannel({ ...data.channel, ...('recipients' in data.channel ? { user: data.user } : undefined) });
 
     // Do not emit this for interactions that cache messages that are non-text-based.
     let InteractionClass;

packages/discord.js/src/structures/DMChannel.js

@@ -32,17 +32,19 @@ class DMChannel extends BaseChannel {
     super._patch(data);
 
     if (data.recipients) {
-      const recipient = data.recipients[0];
-
       /**
-       * The recipient's id
+       * The recipients' ids
        *
-       * @type {Snowflake}
+       * @type {Snowflake[]}
        */
-      this.recipientId = recipient.id;
-
-      if ('username' in recipient || this.client.options.partials.includes(Partials.User)) {
-        this.client.users._add(recipient);
+      this.recipientIds ??= [
+        ...new Set([...(this.recipientIds ?? []), ...data.recipients.map(recipient => recipient.id)]),
+      ];
+
+      for (const recipient of data.recipients) {
+        if ('username' in recipient || this.client.options.partials.includes(Partials.User)) {
+          this.client.users._add(recipient);
+        }
       }
     }
 
@@ -78,7 +80,21 @@ class DMChannel extends BaseChannel {
   }
 
   /**
-   * The recipient on the other end of the DM
+   * The recipient's id, if this is a DMChannel with the client user.
+   *
+   * @type {?Snowflake}
+   * @readonly
+   */
+  get recipientId() {
+    if (this.recipientIds.includes(this.client.user.id)) {
+      return this.recipientIds.find(recipientId => recipientId !== this.client.user.id) ?? null;
+    }
+
+    return null;
+  }
+
+  /**
+   * The recipient on the other end of the DM, if this is a DMChannel with the client user.
    *
    * @type {?User}
    * @readonly

packages/discord.js/typings/index.d.ts

@@ -1292,7 +1292,8 @@ export interface DMChannel
 export class DMChannel extends BaseChannel {
   private constructor(client: Client<true>, data?: RawDMChannelData);
   public flags: Readonly<ChannelFlagsBitField>;
-  public recipientId: Snowflake;
+  public get recipientId(): Snowflake | null;
+  public recipientIds: Snowflake[];
   public get recipient(): User | null;
   public type: ChannelType.DM;
   public fetch(force?: boolean): Promise<this>;