Merge branch 'copilot/investigate-performance-regression' into develop

.gitignore

@@ -1,3 +1,4 @@
 /node_modules/
 yarn-error.log*
-coverage/
+coverage/
+package-lock.json

packages/nicolium/src/modals/antenna-editor-modal.tsx

@@ -72,8 +72,9 @@ interface IAntennaAccountsForm {
 const AntennaAccountsForm: React.FC<IAntennaAccountsForm> = ({ antennaId, excluded = false }) => {
   const [searchValue, setSearchValue] = useState('');
 
-  const { data: accountIds = [], isFetching: isFetchingAccounts } = useAntennaAccounts(antennaId);
-  const { data: excludedAccountIds = [], isFetching: isFetchingExcludedAccounts } =
+  const { data: accountIds = [] as Array<string>, isFetching: isFetchingAccounts } =
+    useAntennaAccounts(antennaId);
+  const { data: excludedAccountIds = [] as Array<string>, isFetching: isFetchingExcludedAccounts } =
     useAntennaExcludedAccounts(antennaId);
   const { data: searchAccountIds = [] } = useAccountSearch(searchValue, {
     following: true,

packages/nicolium/src/modals/circle-editor-modal.tsx

@@ -45,7 +45,8 @@ const CircleEditorModal: React.FC<BaseModalProps & CircleEditorModalProps> = ({
 
   const { data: circle } = useCircle(circleId);
   const { mutate: updateCircle, isPending: disabled } = useUpdateCircle(circleId);
-  const { data: accountIds = [], isFetching: isFetchingAccounts } = useCircleAccounts(circleId);
+  const { data: accountIds = [] as Array<string>, isFetching: isFetchingAccounts } =
+    useCircleAccounts(circleId);
   const { data: searchAccountIds = [] } = useAccountSearch(searchValue, {
     following: true,
     limit: 5,

packages/nicolium/src/modals/list-editor-modal/components/list-members-form.tsx

@@ -22,7 +22,7 @@ interface IListMembersForm {
 const ListMembersForm: React.FC<IListMembersForm> = ({ listId }) => {
   const [searchValue, setSearchValue] = useState('');
 
-  const { data: accountIds = [], isFetching } = useListAccounts(listId);
+  const { data: accountIds = [] as Array<string>, isFetching } = useListAccounts(listId);
   const { data: searchAccountIds = [] } = useAccountSearch(searchValue, {
     following: true,
     limit: 5,

packages/nicolium/src/queries/utils/make-paginated-response-query-options.ts

@@ -48,14 +48,11 @@ const makePaginatedResponseQueryOptions =
           }
 
           if (Array.isArray(lastPage.items)) {
-            const items = new PaginatedResponseArray(
-              ...data.pages.flatMap((page) =>
+            const items = PaginatedResponseArray.from(
+              data.pages.flatMap((page) =>
                 Array.isArray(page.items) ? page.items : [page.items],
               ),
-            );
-
-            items.total = lastPage.total;
-            items.partial = lastPage.partial;
+            ).setMeta(lastPage.total, lastPage.partial);
 
             return items as T3;
           }

packages/nicolium/src/queries/utils/make-paginated-response-query.ts

@@ -11,8 +11,23 @@ import { useOwnAccount } from '@/hooks/use-own-account';
 import type { PaginatedResponse, PlApiClient } from 'pl-api';
 
 class PaginatedResponseArray<T> extends Array<T> {
-  total?: number;
-  partial?: boolean;
+  declare total: number | undefined;
+  declare partial: boolean | undefined;
+
+  static override from<T>(items: ArrayLike<T> | Iterable<T>): PaginatedResponseArray<T> {
+    const arr = new PaginatedResponseArray<T>();
+    for (const item of Array.from(items)) {
+      arr.push(item);
+    }
+    return arr;
+  }
+
+  /** Set metadata as non-enumerable to preserve TanStack Query structural sharing. */
+  setMeta(total: number | undefined, partial: boolean | undefined): this {
+    Object.defineProperty(this, 'total', { value: total, writable: true, enumerable: false, configurable: true });
+    Object.defineProperty(this, 'partial', { value: partial, writable: true, enumerable: false, configurable: true });
+    return this;
+  }
 }
 
 type PaginatedResponseQueryResult<T, IsArray extends boolean> = IsArray extends true
@@ -59,14 +74,11 @@ const makePaginatedResponseQuery =
           }
 
           if (Array.isArray(lastPage.items)) {
-            const items = new PaginatedResponseArray(
-              ...data.pages.flatMap((page) =>
+            const items = PaginatedResponseArray.from(
+              data.pages.flatMap((page) =>
                 Array.isArray(page.items) ? page.items : [page.items],
               ),
-            );
-
-            items.total = lastPage.total;
-            items.partial = lastPage.partial;
+            ).setMeta(lastPage.total, lastPage.partial);
 
             return items as T3;
           }

packages/nicolium/tests/queries/utils/paginated-response-array.test.ts

@@ -0,0 +1,46 @@
+import { describe, expect, it } from 'vitest';
+
+import { PaginatedResponseArray } from '@/queries/utils/make-paginated-response-query';
+
+/**
+ * TanStack Query's isPlainArray check used for structural sharing.
+ * If this returns false, structural sharing breaks, causing new references
+ * on every render and leading to performance degradation.
+ */
+const isPlainArray = (value: unknown): boolean =>
+  Array.isArray(value) && (value as Array<unknown>).length === Object.keys(value as object).length;
+
+describe('PaginatedResponseArray', () => {
+  it('creates an array from items without spread operator', () => {
+    const items = PaginatedResponseArray.from([1, 2, 3]);
+    expect(items).toEqual([1, 2, 3]);
+    expect(items.length).toBe(3);
+    expect(items instanceof PaginatedResponseArray).toBe(true);
+  });
+
+  it('handles large arrays without stack overflow', () => {
+    const largeArray = Array.from({ length: 100_000 }, (_, i) => i);
+    const items = PaginatedResponseArray.from(largeArray);
+    expect(items.length).toBe(100_000);
+  });
+
+  it('supports non-enumerable total and partial properties via setMeta', () => {
+    const items = PaginatedResponseArray.from(['a', 'b', 'c']).setMeta(42, true);
+
+    expect(items.total).toBe(42);
+    expect(items.partial).toBe(true);
+  });
+
+  it('passes isPlainArray check with non-enumerable properties for structural sharing', () => {
+    const items = PaginatedResponseArray.from([1, 2, 3]).setMeta(10, false);
+
+    expect(isPlainArray(items)).toBe(true);
+  });
+
+  it('total and partial properties are writable after setMeta', () => {
+    const items = PaginatedResponseArray.from([1]).setMeta(5, false);
+
+    items.total = 10;
+    expect(items.total).toBe(10);
+  });
+});