Add useGetAggregateFromServerQuery hook

packages/react/src/firestore/index.ts

@@ -7,6 +7,8 @@
 // useWriteBatchCommitMutation (WriteBatch)
 export { useDocumentQuery } from "./useDocumentQuery";
 export { useCollectionQuery } from "./useCollectionQuery";
+// useGetCountFromServerQuery
+export { useGetAggregateFromServerQuery } from "./useGetAggregateFromServerQuery";
 export { useGetCountFromServerQuery } from "./useGetCountFromServerQuery";
 // useGetAggregateFromServerQuery
 // useNamedQuery

packages/react/src/firestore/useGetAggregateFromServerQuery.test.tsx

@@ -0,0 +1,154 @@
+import React, { type ReactNode } from "react";
+import { describe, expect, test, beforeEach } from "vitest";
+import { useGetAggregateFromServerQuery } from "./useGetAggregateFromServerQuery";
+import { renderHook, waitFor } from "@testing-library/react";
+import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
+import {
+  collection,
+  addDoc,
+  query,
+  where,
+  sum,
+  average,
+  count,
+} from "firebase/firestore";
+import {
+  expectFirestoreError,
+  firestore,
+  wipeFirestore,
+} from "~/testing-utils";
+
+const queryClient = new QueryClient({
+  defaultOptions: {
+    queries: {
+      retry: false,
+    },
+  },
+});
+
+const wrapper = ({ children }: { children: ReactNode }) => (
+  <QueryClientProvider client={queryClient}>{children}</QueryClientProvider>
+);
+
+describe("useGetAggregateFromServerQuery", () => {
+  beforeEach(async () => await wipeFirestore());
+
+  test("returns correct count for empty collection", async () => {
+    const collectionRef = collection(firestore, "tests");
+
+    const { result } = renderHook(
+      () =>
+        useGetAggregateFromServerQuery(
+          collectionRef,
+          { countOfDocs: count() },
+          { queryKey: ["aggregate", "empty"] }
+        ),
+      { wrapper }
+    );
+
+    await waitFor(() => expect(result.current.isSuccess).toBe(true));
+
+    expect(result.current.data?.data().countOfDocs).toBe(0);
+  });
+
+  test("returns correct aggregate values for non-empty collection", async () => {
+    const collectionRef = collection(firestore, "tests");
+
+    await addDoc(collectionRef, { value: 10 });
+    await addDoc(collectionRef, { value: 20 });
+    await addDoc(collectionRef, { value: 30 });
+
+    const { result } = renderHook(
+      () =>
+        useGetAggregateFromServerQuery(
+          collectionRef,
+          {
+            countOfDocs: count(),
+            averageValue: average("value"),
+            totalValue: sum("value"),
+          },
+          { queryKey: ["aggregate", "non-empty"] }
+        ),
+      { wrapper }
+    );
+
+    await waitFor(() => expect(result.current.isSuccess).toBe(true));
+
+    expect(result.current.data?.data().averageValue).toBe(20);
+    expect(result.current.data?.data().totalValue).toBe(60);
+    expect(result.current.data?.data().countOfDocs).toBe(3);
+  });
+
+  test("handles complex queries", async () => {
+    const collectionRef = collection(firestore, "tests");
+
+    await addDoc(collectionRef, { category: "A", books: 10 });
+    await addDoc(collectionRef, { category: "B", books: 20 });
+    await addDoc(collectionRef, { category: "A", books: 30 });
+    await addDoc(collectionRef, { category: "C", books: 40 });
+
+    const complexQuery = query(collectionRef, where("category", "==", "A"));
+
+    const { result } = renderHook(
+      () =>
+        useGetAggregateFromServerQuery(
+          complexQuery,
+          {
+            countOfDocs: count(),
+            averageNumberOfBooks: average("books"),
+            totalNumberOfBooks: sum("books"),
+          },
+          { queryKey: ["aggregate", "complex"] }
+        ),
+      {
+        wrapper,
+      }
+    );
+
+    await waitFor(() => expect(result.current.isSuccess).toBe(true));
+
+    expect(result.current.data?.data().averageNumberOfBooks).toBe(20);
+    expect(result.current.data?.data().totalNumberOfBooks).toBe(40);
+    expect(result.current.data?.data().countOfDocs).toBe(2);
+  });
+
+  test("handles restricted collection appropriately", async () => {
+    const collectionRef = collection(firestore, "restrictedCollection");
+
+    const { result } = renderHook(
+      () =>
+        useGetAggregateFromServerQuery(
+          collectionRef,
+          { count: count() },
+          { queryKey: ["aggregate", "restricted"] }
+        ),
+      { wrapper }
+    );
+
+    await waitFor(() => expect(result.current.isError).toBe(true));
+
+    expectFirestoreError(result.current.error, "permission-denied");
+  });
+
+  test("returns pending state initially", async () => {
+    const collectionRef = collection(firestore, "tests");
+
+    await addDoc(collectionRef, { value: 10 });
+
+    const { result } = renderHook(
+      () =>
+        useGetAggregateFromServerQuery(
+          collectionRef,
+          { count: count() },
+          { queryKey: ["aggregate", "pending"] }
+        ),
+      { wrapper }
+    );
+
+    expect(result.current.isPending).toBe(true);
+
+    await waitFor(() => expect(result.current.isSuccess).toBe(true));
+
+    expect(result.current.data?.data().count).toBe(1);
+  });
+});

packages/react/src/firestore/useGetAggregateFromServerQuery.ts

@@ -0,0 +1,35 @@
+import { useQuery, type UseQueryOptions } from "@tanstack/react-query";
+import {
+  type Query,
+  type FirestoreError,
+  getAggregateFromServer,
+  type AggregateSpec,
+  type DocumentData,
+  type AggregateQuerySnapshot,
+} from "firebase/firestore";
+
+type FirestoreUseQueryOptions<TData = unknown, TError = Error> = Omit<
+  UseQueryOptions<TData, TError>,
+  "queryFn"
+>;
+
+export function useGetAggregateFromServerQuery<
+  T extends AggregateSpec,
+  AppModelType = DocumentData,
+  DbModelType extends DocumentData = DocumentData
+>(
+  query: Query<AppModelType, DbModelType>,
+  aggregateSpec: T,
+  options: FirestoreUseQueryOptions<
+    AggregateQuerySnapshot<T, AppModelType, DbModelType>,
+    FirestoreError
+  >
+) {
+  return useQuery<
+    AggregateQuerySnapshot<T, AppModelType, DbModelType>,
+    FirestoreError
+  >({
+    ...options,
+    queryFn: () => getAggregateFromServer(query, aggregateSpec),
+  });
+}