fix(GuildAuditLogsEntry): correct mapped AuditLogChange objects (#10438)

* refactor(GuildAuditLogsEntry): correct mapped AuditLogChange objects

* test: check union narrowing behaviour of AuditLogChange

---------

Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

Author: Renegade334

packages/discord.js/src/structures/GuildAuditLogsEntry.js

@@ -172,7 +172,11 @@ class GuildAuditLogsEntry {
      * @type {AuditLogChange[]}
      */
     this.changes =
-      data.changes?.map(change => ({ key: change.key, old: change.old_value, new: change.new_value })) ?? [];
+      data.changes?.map(change => ({
+        key: change.key,
+        ...('old_value' in change ? { old: change.old_value } : {}),
+        ...('new_value' in change ? { new: change.new_value } : {}),
+      })) ?? [];
 
     /**
      * The entry's id

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

@@ -4991,11 +4991,13 @@ export interface ApplicationRoleConnectionMetadataEditOptions {
   type: ApplicationRoleConnectionMetadataType;
 }
 
-export interface AuditLogChange {
-  key: APIAuditLogChange['key'];
-  old?: APIAuditLogChange['old_value'];
-  new?: APIAuditLogChange['new_value'];
-}
+export type AuditLogChange = {
+  [SourceElement in APIAuditLogChange as SourceElement['key']]: {
+    key: SourceElement['key'];
+    old?: SourceElement['old_value'];
+    new?: SourceElement['new_value'];
+  };
+}[APIAuditLogChange['key']];
 
 export interface AutoModerationAction {
   type: AutoModerationActionType;

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

@@ -104,6 +104,7 @@ import {
   Collector,
   GuildAuditLogsEntry,
   GuildAuditLogs,
+  type AuditLogChange,
   StageInstance,
   ActionRowBuilder,
   ButtonComponent,
@@ -2171,6 +2172,16 @@ expectType<Promise<User | undefined>>(
   guild.fetchAuditLogs({ type: AuditLogEvent.MessageDelete }).then(al => al.entries.first()?.target),
 );
 
+declare const AuditLogChange: AuditLogChange;
+// @ts-expect-error
+expectType<boolean | undefined>(AuditLogChange.old);
+// @ts-expect-error
+expectType<boolean | undefined>(AuditLogChange.new);
+if (AuditLogChange.key === 'available') {
+  expectType<boolean | undefined>(AuditLogChange.old);
+  expectType<boolean | undefined>(AuditLogChange.new);
+}
+
 declare const TextBasedChannel: TextBasedChannel;
 declare const TextBasedChannelTypes: TextBasedChannelTypes;
 declare const VoiceBasedChannel: VoiceBasedChannel;