fix: convert BigInt totalItems to number in fetchAllPages to prevent TypeError

Co-authored-by: vobu <6573426+vobu@users.noreply.github.com>

Author: Copilot

src/client.ts

@@ -62,7 +62,7 @@ export const DEFAULT_MAX_ITEMS = 1_000_000;
 type PagedResponse<T> = {
   items?: T[];
   page?: {
-    totalItems?: number;
+    totalItems?: bigint | number;
     endCursor?: string;
     startCursor?: string;
     hasMoreTotalItems?: boolean;
@@ -111,8 +111,9 @@ export async function fetchAllPages<T>(
       break;
     }
 
-    const endCursor = result.page?.endCursor ?? (result as any).page?.endCursor as string | undefined;
-    const totalItems = result.page?.totalItems ?? (result as any).page?.totalItems as number | undefined;
+    const endCursor = result.page?.endCursor;
+    // totalItems is BigInt from the SDK's Zod schema (z.coerce.bigint()); convert to number
+    const totalItems = result.page?.totalItems !== undefined ? Number(result.page.totalItems) : undefined;
 
     if (!endCursor || seenCursors.has(endCursor)) break;
     if (totalItems !== undefined && allItems.length >= totalItems) break;

tests/unit/fetch-all-pages.test.ts

@@ -218,4 +218,26 @@ describe('fetchAllPages', () => {
   test('DEFAULT_MAX_ITEMS is 1000000', () => {
     assert.strictEqual(DEFAULT_MAX_ITEMS, 1_000_000);
   });
+
+  test('handles BigInt totalItems from SDK Zod schema without throwing', async () => {
+    // The Camunda 8 SDK uses z.coerce.bigint() for totalItems, so it returns BigInt at runtime.
+    // fetchAllPages must convert it to number before comparing with allItems.length (a number).
+    let callCount = 0;
+    const bigintTotalItemsSearch = async (_filter: any, _opts?: any) => {
+      callCount++;
+      return {
+        items: [{ id: 1 }, { id: 2 }],
+        page: {
+          totalItems: 2n,  // BigInt, as returned by the SDK
+          endCursor: undefined,
+        },
+      };
+    };
+
+    // Should NOT throw TypeError: Cannot mix BigInt and other types
+    const items = await fetchAllPages(bigintTotalItemsSearch, {});
+
+    assert.strictEqual(callCount, 1, 'should only make one API call');
+    assert.strictEqual(items.length, 2);
+  });
 });