Merge pull request FirebaseExtended#73 from FirebaseExtended/de-count

feat(firestore): add count observables

docs/firestore.md

@@ -231,6 +231,82 @@ deleteDoc(davidDocRef);
   */
 ```
 
+### `collectionCount()`
+
+Create an observable that emits the server-calculated number of documents in a collection or query. [Learn more about count queries in the Firebase docs](https://firebase.google.com/docs/firestore/query-data/aggregation-queries).
+
+|                 |                                          |
+|-----------------|------------------------------------------|
+| **function**    | `collectionCount()`                           |
+| **params**      | query: `import('firebase/firestore').CollectionReference \| import('firebase/firestore').Query`|
+| **import path** | `rxfire/firestore` or `rxfire/firestore/lite`                       |
+| **return**      | `Observable<number>`    |
+
+#### TypeScript Example
+```ts
+import { collectionCount } from 'rxfire/firestore';
+// Also available in firestore/lite
+import { collectionCount } from 'rxfire/firestore/lite';
+
+import { getFirestore, collection } from 'firebase/firestore';
+
+const db = getFirestore();
+const likesCol = collection(db, 'posts/post_id_123/likes');
+
+collectionCount(likesCol).subscribe(count => {
+   console.log(count);
+});
+```
+
+Note that the observable will complete after the first fetch. This is not a long-lived subscription. To update the count value over time, use the `repeat` operator:
+
+```ts
+import { repeat } from 'rxjs';
+
+import { collectionCount} from 'rxfire/firestore';
+import { getFirestore, collection } from 'firebase/firestore';
+
+const db = getFirestore();
+const likesCol = collection(db, 'posts/post_id_123/likes');
+
+collectionCount(likesCol)
+  .pipe(
+    // re-fetch every 30 seconds.
+    // Stop fetching after 100 re-fetches so we don't do too many reads
+    repeat({ count: 100, delay: 30 * 1000 }),
+  )
+  .subscribe((count) => {
+    console.log(count);
+  });
+```
+
+### `collectionCountSnap()`
+
+Create an observable that emits the server-calculated number of documents in a collection or query. [Learn more about count queries in the Firebase docs](https://firebase.google.com/docs/firestore/query-data/aggregation-queries).
+
+|                 |                                          |
+|-----------------|------------------------------------------|
+| **function**    | `collectionCountSnap()`                           |
+| **params**      | query: `import('firebase/firestore').CollectionReference \| import('firebase/firestore').Query`|
+| **import path** | `rxfire/firestore` or `firebase/firestore/lite`                       |
+| **return**      | `Observable<CountSnapshot>`    |
+
+#### TypeScript Example
+```ts
+import { collectionCountSnap } from 'rxfire/firestore';
+// Also available in firestore/lite
+import { collectionCountSnap } from 'rxfire/firestore/lite';
+import { getFirestore, collection } from 'firebase/firestore';
+
+const db = getFirestore();
+const likesCol = collection(db, 'posts/post_id_123/likes');
+
+// One version with the snapshot
+countSnap$(likesCol).subscribe(snapshot => {
+  console.log(snapshot.data().count);
+});
+```
+
 ## Event Observables
 
 ### `fromDocRef()`

firestore/collection/index.ts

@@ -1,6 +1,6 @@
 /**
  * @license
- * Copyright 2018 Google LLC
+ * Copyright 2023 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,6 +22,7 @@ import {
   OperatorFunction,
   pipe,
   UnaryFunction,
+  from,
 } from 'rxjs';
 import {
   map,
@@ -33,7 +34,8 @@ import {
 } from 'rxjs/operators';
 import {snapToData} from '../document';
 import {DocumentChangeType, DocumentChange, Query, QueryDocumentSnapshot, QuerySnapshot, DocumentData} from '../interfaces';
-import {refEqual} from 'firebase/firestore';
+import {getCountFromServer, refEqual} from 'firebase/firestore';
+import {CountSnapshot} from '../lite/interfaces';
 const ALL_EVENTS: DocumentChangeType[] = ['added', 'modified', 'removed'];
 
 /**
@@ -295,3 +297,11 @@ export function collectionData<T=DocumentData, U extends string=never>(
       }),
   );
 }
+
+export function collectionCountSnap(query: Query<unknown>): Observable<CountSnapshot> {
+  return from(getCountFromServer(query));
+}
+
+export function collectionCount(query: Query<unknown>): Observable<number> {
+  return collectionCountSnap(query).pipe(map((snap) => snap.data().count));
+}

firestore/lite/collection/index.ts

@@ -1,6 +1,6 @@
 /**
  * @license
- * Copyright 2018 Google LLC
+ * Copyright 2023 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,15 +18,15 @@
 import {Observable, from} from 'rxjs';
 import {map} from 'rxjs/operators';
 import {snapToData} from '../document';
-import {Query, QueryDocumentSnapshot, DocumentData} from '../interfaces';
-import {getDocs} from 'firebase/firestore/lite';
+import {Query, QueryDocumentSnapshot, DocumentData, CountSnapshot} from '../interfaces';
+import {getDocs, getCount} from 'firebase/firestore/lite';
 
 /**
  * Return a stream of document snapshots on a query. These results are in sort order.
  * @param query
  */
 export function collection<T=DocumentData>(query: Query<T>): Observable<QueryDocumentSnapshot<T>[]> {
-  return from(getDocs<T>(query)).pipe(
+  return from(getDocs<T, DocumentData>(query)).pipe(
       map((changes) => changes.docs),
   );
 }
@@ -47,3 +47,11 @@ export function collectionData<T=DocumentData>(
       }),
   );
 }
+
+export function collectionCountSnap(query: Query<unknown>): Observable<CountSnapshot> {
+  return from(getCount(query));
+}
+
+export function collectionCount(query: Query<unknown>): Observable<number> {
+  return collectionCountSnap(query).pipe(map((snap) => snap.data().count));
+}

firestore/lite/document/index.ts

@@ -22,7 +22,7 @@ import {from, Observable} from 'rxjs';
 import {getDoc} from 'firebase/firestore/lite';
 
 export function doc<T=DocumentData>(ref: DocumentReference<T>): Observable<DocumentSnapshot<T>> {
-  return from(getDoc<T>(ref));
+  return from(getDoc<T, DocumentData>(ref));
 }
 
 /**

firestore/lite/fromRef.ts

@@ -6,8 +6,8 @@ export function fromRef<T=DocumentData>(ref: DocumentReference<T>): Observable<D
 export function fromRef<T=DocumentData>(ref: Query<T>): Observable<QuerySnapshot<T>>;
 export function fromRef<T=DocumentData>(ref: DocumentReference<T>|Query<T>): Observable<DocumentSnapshot<T> | QuerySnapshot<T>> {
   if (ref.type === 'document') {
-    return from(getDoc<T>(ref));
+    return from(getDoc<T, DocumentData>(ref));
   } else {
-    return from(getDocs<T>(ref));
+    return from(getDocs<T, DocumentData>(ref));
   }
 }

firestore/lite/interfaces.ts

@@ -1,6 +1,11 @@
-export type DocumentReference<T> = import('firebase/firestore/lite').DocumentReference<T>;
-export type DocumentData = import('firebase/firestore/lite').DocumentData;
-export type Query<T> = import('firebase/firestore/lite').Query<T>;
-export type DocumentSnapshot<T> = import('firebase/firestore/lite').DocumentSnapshot<T>;
-export type QuerySnapshot<T> = import('firebase/firestore/lite').QuerySnapshot<T>;
-export type QueryDocumentSnapshot<T> = import('firebase/firestore/lite').QueryDocumentSnapshot<T>;
+import type * as lite from 'firebase/firestore/lite';
+
+export type DocumentReference<T> = lite.DocumentReference<T>;
+export type DocumentData = lite.DocumentData;
+export type Query<T> = lite.Query<T>;
+export type DocumentSnapshot<T> = lite.DocumentSnapshot<T>;
+export type QuerySnapshot<T> = lite.QuerySnapshot<T>;
+export type QueryDocumentSnapshot<T> = lite.QueryDocumentSnapshot<T>;
+export type CountSnapshot = lite.AggregateQuerySnapshot<{
+  count: lite.AggregateField<number>;
+}, any, DocumentData>;

package.json

@@ -73,8 +73,8 @@
     "build:docs": "cp README.md ./dist/ && cp -r ./docs ./dist/",
     "dev": "rollup -c -w",
     "echo:chrome": "echo 'Open Chrome DevTools: \nchrome://inspect/#devices'",
-    "test": "FIREBASE_CLI_PREVIEWS=storageemulator firebase emulators:exec \"jest --detectOpenHandles\" --project=rxfire-test-c497c ",
-    "test:debug": "yarn echo:chrome && FIREBASE_CLI_PREVIEWS=storageemulator firebase emulators:exec ./test-debug.sh --project=rxfire-test-c497c"
+    "test": "firebase emulators:exec \"jest --detectOpenHandles\" --project=rxfire-test-c497c ",
+    "test:debug": "yarn echo:chrome && firebase emulators:exec ./test-debug.sh --project=rxfire-test-c497c"
   },
   "dependencies": {},
   "peerDependencies": {
@@ -95,8 +95,8 @@
     "cross-fetch": "^3.1.4",
     "eslint": "^7.32.0",
     "eslint-config-google": "^0.14.0",
-    "firebase": "^9.0.0",
-    "firebase-tools": "^9.10.2",
+    "firebase": "^10.0.0",
+    "firebase-tools": "^12.4.3",
     "glob": "^7.1.6",
     "jest": "^26.6.3",
     "md5": "^2.3.0",

test/firestore-lite.test.ts

@@ -4,7 +4,7 @@
 
 /**
  * @license
- * Copyright 2021 Google LLC
+ * Copyright 2023 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -27,10 +27,12 @@ import {
   collection,
   docData,
   collectionData,
+  collectionCountSnap,
+  collectionCount,
 } from '../dist/firestore/lite';
 import {map} from 'rxjs/operators';
 import {default as TEST_PROJECT, firestoreEmulatorPort} from './config';
-import {doc as firestoreDoc, getDocs, collection as firestoreCollection, getDoc, Firestore as FirebaseFirestore, CollectionReference, getFirestore, DocumentReference, connectFirestoreEmulator, doc, setDoc, collection as baseCollection, QueryDocumentSnapshot} from 'firebase/firestore/lite';
+import {doc as firestoreDoc, getDocs, collection as firestoreCollection, getDoc, Firestore as FirebaseFirestore, CollectionReference, getFirestore, DocumentReference, connectFirestoreEmulator, doc, setDoc, collection as baseCollection, QueryDocumentSnapshot, addDoc} from 'firebase/firestore/lite';
 import {initializeApp, deleteApp, FirebaseApp} from 'firebase/app';
 
 const createId = (): string => Math.random().toString(36).substring(5);
@@ -80,8 +82,10 @@ describe('RxFire firestore/lite', () => {
     connectFirestoreEmulator(firestore, 'localhost', firestoreEmulatorPort);
   });
 
-  afterEach(() => {
-    deleteApp(app).catch(() => undefined);
+  afterEach((done) => {
+    deleteApp(app)
+        .then(() => done())
+        .catch(() => undefined);
   });
 
   describe('collection', () => {
@@ -105,7 +109,6 @@ describe('RxFire firestore/lite', () => {
     });
   });
 
-
   describe('collection w/converter', () => {
     /**
      * This is a simple test to see if the collection() method
@@ -222,4 +225,37 @@ describe('RxFire firestore/lite', () => {
       });
     });
   });
+
+  describe('Aggregations', () => {
+    it('should provide an observable with a count aggregate', async (done) => {
+      const colRef = createRandomCol(firestore);
+      const entries = [
+        addDoc(colRef, {id: createId()}),
+        addDoc(colRef, {id: createId()}),
+      ];
+      await Promise.all(entries);
+
+      collectionCountSnap(colRef).subscribe((snap) => {
+        expect(snap.data().count).toEqual(entries.length);
+        done();
+      });
+    });
+
+    it('should provide an observable with a count aggregate number', async (done) => {
+      const colRef = createRandomCol(firestore);
+      const entries = [
+        addDoc(colRef, {id: createId()}),
+        addDoc(colRef, {id: createId()}),
+        addDoc(colRef, {id: createId()}),
+        addDoc(colRef, {id: createId()}),
+        addDoc(colRef, {id: createId()}),
+      ];
+      await Promise.all(entries);
+
+      collectionCount(colRef).subscribe((count) => {
+        expect(count).toEqual(entries.length);
+        done();
+      });
+    });
+  });
 });

test/firestore.test.ts

@@ -4,7 +4,7 @@
 
 /**
  * @license
- * Copyright 2021 Google LLC
+ * Copyright 2023 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -30,10 +30,12 @@ import {
   auditTrail,
   docData,
   collectionData,
+  collectionCountSnap,
+  collectionCount,
 } from '../dist/firestore';
 import {map, take, skip} from 'rxjs/operators';
 import {default as TEST_PROJECT, firestoreEmulatorPort} from './config';
-import {getDocs, collection as firestoreCollection, getDoc, DocumentReference, doc as firestoreDoc, Firestore as FirebaseFirestore, CollectionReference, getFirestore, updateDoc, connectFirestoreEmulator, doc, setDoc, DocumentChange, collection as baseCollection, QueryDocumentSnapshot} from 'firebase/firestore';
+import {getDocs, collection as firestoreCollection, getDoc, DocumentReference, doc as firestoreDoc, Firestore as FirebaseFirestore, CollectionReference, getFirestore, updateDoc, connectFirestoreEmulator, doc, setDoc, DocumentChange, collection as baseCollection, QueryDocumentSnapshot, addDoc} from 'firebase/firestore';
 import {initializeApp, deleteApp, FirebaseApp} from 'firebase/app';
 
 const createId = (): string => Math.random().toString(36).substring(5);
@@ -422,4 +424,37 @@ describe('RxFire Firestore', () => {
       });
     });
   });
+
+  describe('Aggregations', () => {
+    it('should provide an observable with a count aggregate snapshot', async (done) => {
+      const colRef = createRandomCol(firestore);
+      const entries = [
+        addDoc(colRef, {id: createId()}),
+        addDoc(colRef, {id: createId()}),
+      ];
+      await Promise.all(entries);
+
+      collectionCountSnap(colRef).subscribe((snap) => {
+        expect(snap.data().count).toEqual(entries.length);
+        done();
+      });
+    });
+
+    it('should provide an observable with a count aggregate number', async (done) => {
+      const colRef = createRandomCol(firestore);
+      const entries = [
+        addDoc(colRef, {id: createId()}),
+        addDoc(colRef, {id: createId()}),
+        addDoc(colRef, {id: createId()}),
+        addDoc(colRef, {id: createId()}),
+        addDoc(colRef, {id: createId()}),
+      ];
+      await Promise.all(entries);
+
+      collectionCount(colRef).subscribe((count) => {
+        expect(count).toEqual(entries.length);
+        done();
+      });
+    });
+  });
 });

test/functions/package.json

@@ -10,11 +10,14 @@
   },
   "main": "index.js",
   "dependencies": {
-    "firebase-admin": "^9.2.0",
-    "firebase-functions": "^3.11.0"
+    "firebase-admin": "^11.9.0",
+    "firebase-functions": "^4.4.1"
   },
   "devDependencies": {
-    "firebase-functions-test": "^0.2.0"
+    "firebase-functions-test": "^3.1.0"
+  },
+  "engines": {
+    "node": "20"
   },
   "private": true
 }