Add getDocFromCache() & getDocFromServer() (#3285)

Author: schmidt-sebastian

.changeset/tall-pots-brush.md

@@ -0,0 +1,2 @@
+---
+---

packages/firestore/exp/index.node.ts

@@ -44,7 +44,7 @@ export {
 
 export { runTransaction, Transaction } from '../lite/src/api/transaction';
 
-export { getDoc } from './src/api/reference';
+export { getDoc, getDocFromCache, getDocFromServer } from './src/api/reference';
 
 export {
   FieldValue,

packages/firestore/exp/src/api/reference.ts

@@ -30,14 +30,55 @@ import {
 } from '../../../src/api/database';
 import { ViewSnapshot } from '../../../src/core/view_snapshot';
 import { DocumentReference } from '../../../lite/src/api/reference';
+import { Document } from '../../../src/model/document';
 
 export function getDoc<T>(
   reference: firestore.DocumentReference<T>
 ): Promise<firestore.DocumentSnapshot<T>> {
   const ref = cast<DocumentReference<T>>(reference, DocumentReference);
   const firestore = cast<Firestore>(ref.firestore, Firestore);
   return firestore._getFirestoreClient().then(async firestoreClient => {
-    const viewSnapshot = await getDocViaSnapshotListener(firestoreClient, ref);
+    const viewSnapshot = await getDocViaSnapshotListener(
+      firestoreClient,
+      ref._key
+    );
+    return convertToDocSnapshot(firestore, ref, viewSnapshot);
+  });
+}
+
+// TODO(firestorexp): Make sure we don't include Datastore/RemoteStore in builds
+// that only include `getDocFromCache`.
+export function getDocFromCache<T>(
+  reference: firestore.DocumentReference<T>
+): Promise<firestore.DocumentSnapshot<T>> {
+  const ref = cast<DocumentReference<T>>(reference, DocumentReference);
+  const firestore = cast<Firestore>(ref.firestore, Firestore);
+  return firestore._getFirestoreClient().then(async firestoreClient => {
+    const doc = await firestoreClient.getDocumentFromLocalCache(ref._key);
+    return new DocumentSnapshot(
+      firestore,
+      ref._key,
+      doc,
+      ref._converter,
+      new SnapshotMetadata(
+        doc instanceof Document ? doc.hasLocalMutations : false,
+        /* fromCache= */ true
+      )
+    );
+  });
+}
+
+export function getDocFromServer<T>(
+  reference: firestore.DocumentReference<T>
+): Promise<firestore.DocumentSnapshot<T>> {
+  const ref = cast<DocumentReference<T>>(reference, DocumentReference);
+  const firestore = cast<Firestore>(ref.firestore, Firestore);
+  return firestore._getFirestoreClient().then(async firestoreClient => {
+    const viewSnapshot = await getDocViaSnapshotListener(
+      firestoreClient,
+      ref._key,
+      { source: 'server' }
+    );
     return convertToDocSnapshot(firestore, ref, viewSnapshot);
   });
 }

packages/firestore/exp/test/integration.test.ts

@@ -25,7 +25,11 @@ import {
   initializeFirestore
 } from '../src/api/database';
 import { withTestDoc } from './helpers';
-import { getDoc } from '../src/api/reference';
+import {
+  getDoc,
+  getDocFromCache,
+  getDocFromServer
+} from '../src/api/reference';
 
 use(chaiAsPromised);
 
@@ -61,3 +65,25 @@ describe('getDoc()', () => {
     });
   });
 });
+
+describe('getDocFromCache()', () => {
+  it('can get a non-existing document', () => {
+    return withTestDoc(async docRef => {
+      await expect(getDocFromCache(docRef)).to.eventually.be.rejectedWith(
+        /Failed to get document from cache./
+      );
+    });
+  });
+});
+
+describe('getDocFromServer()', () => {
+  it('can get a non-existing document', () => {
+    return withTestDoc(async docRef => {
+      const docSnap = await getDocFromServer(docRef);
+      expect(docSnap.metadata.fromCache).to.be.false;
+      expect(docSnap.metadata.hasPendingWrites).to.be.false;
+      expect(docSnap.data()).to.be.undefined;
+      expect(docSnap.exists()).to.be.false;
+    });
+  });
+});