more handler fixes for threads

src/util/transformers/mod.ts

@@ -1,2 +1,3 @@
 export * from "./channel_to_thread.ts";
 export * from "./thread_member_modified.ts";
+export * from "./thread_members_update_modified.ts"

src/util/transformers/thread_members_update_modified.ts

@@ -0,0 +1,16 @@
+import {
+  ThreadMembersUpdate,
+  ThreadMembersUpdateModified,
+} from "../../types/channels/threads/thread_members_update.ts";
+import { snowflakeToBigint } from "../bigint.ts";
+import { threadMemberModified } from "./thread_member_modified.ts";
+
+export function threadMembersUpdateModified(data: ThreadMembersUpdate) {
+  return {
+    ...data,
+    id: snowflakeToBigint(data.id),
+    guildId: snowflakeToBigint(data.guildId),
+    addedMembers: data.addedMembers?.map((member) => threadMemberModified(member)) || [],
+    removedMemberIds: data.removedMemberIds?.map((id) => snowflakeToBigint(id)) || [],
+  } as ThreadMembersUpdateModified;
+}