Don't double-block AsyncQueue on auth token retrieval (#5434)

.changeset/cyan-eagles-carry.md

@@ -0,0 +1,5 @@
+---
+"@firebase/firestore": patch
+---
+
+Fixes a deadlock during asynchronous initialization of both Firestore and Auth.

packages/firestore/package.json

@@ -83,6 +83,7 @@
   "devDependencies": {
     "@firebase/app": "0.7.0",
     "@firebase/app-compat": "0.1.1",
+    "@firebase/auth": "0.17.1",
     "@rollup/plugin-alias": "3.1.2",
     "@rollup/plugin-json": "4.1.0",
     "@types/eslint": "7.2.10",

packages/firestore/src/api/credentials.ts

@@ -108,8 +108,8 @@ export interface CredentialsProvider {
   shutdown(): void;
 }
 
-/** 
- * A CredentialsProvider that always yields an empty token. 
+/**
+ * A CredentialsProvider that always yields an empty token.
  * @internal
  */
 export class EmptyCredentialsProvider implements CredentialsProvider {
@@ -261,18 +261,21 @@ export class FirebaseCredentialsProvider implements CredentialsProvider {
       );
     };
 
-    const registerAuth = (auth: FirebaseAuthInternal): void => {
+    const awaitNextToken: () => void = () => {
+      const currentTokenAttempt = nextToken;
       asyncQueue.enqueueRetryable(async () => {
-        logDebug('FirebaseCredentialsProvider', 'Auth detected');
-        this.auth = auth;
-        this.auth.addAuthTokenListener(this.tokenListener);
-
-        // Call the change listener inline to block on the user change.
-        await nextToken.promise;
+        await currentTokenAttempt.promise;
         await guardedChangeListener(this.currentUser);
       });
     };
 
+    const registerAuth = (auth: FirebaseAuthInternal): void => {
+      logDebug('FirebaseCredentialsProvider', 'Auth detected');
+      this.auth = auth;
+      this.auth.addAuthTokenListener(this.tokenListener);
+      awaitNextToken();
+    };
+
     this.authProvider.onInit(auth => registerAuth(auth));
 
     // Our users can initialize Auth right after Firestore, so we give it
@@ -292,13 +295,7 @@ export class FirebaseCredentialsProvider implements CredentialsProvider {
       }
     }, 0);
 
-    asyncQueue.enqueueRetryable(async () => {
-      // If we have not received a token, wait for the first one.
-      if (this.tokenCounter === 0) {
-        await nextToken.promise;
-        await guardedChangeListener(this.currentUser);
-      }
-    });
+    awaitNextToken();
   }
 
   getToken(): Promise<Token | null> {

packages/firestore/test/integration/api_internal/auth.test.ts

@@ -0,0 +1,157 @@
+/**
+ * @license
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { FirebaseApp, initializeApp } from '@firebase/app';
+import { getAuth, signInAnonymously } from '@firebase/auth';
+import { expect } from 'chai';
+
+import {
+  getDoc,
+  getFirestore,
+  doc,
+  enableIndexedDbPersistence,
+  disableNetwork,
+  setDoc
+} from '../../../src';
+
+// eslint-disable-next-line @typescript-eslint/no-require-imports
+const firebaseConfig = require('../../../../../config/project.json');
+
+let appCount = 0;
+
+function getNextApp(): FirebaseApp {
+  const name = 'initialization-test-app-' + appCount++;
+  return initializeApp(firebaseConfig, name);
+}
+
+describe('Initialization', () => {
+  let app: FirebaseApp;
+
+  beforeEach(() => {
+    app = getNextApp();
+  });
+
+  it('getAuth() before getFirestore()', () => {
+    getAuth(app);
+    const firestore = getFirestore(app);
+    const testDoc = doc(firestore, 'coll/doc');
+    return getDoc(testDoc);
+  });
+
+  it('getFirestore() before getAuth()', () => {
+    const firestore = getFirestore(app);
+    getAuth(app);
+    const testDoc = doc(firestore, 'coll/doc');
+    return getDoc(testDoc);
+  });
+
+  it('lazy-loaded getAuth()', () => {
+    const firestore = getFirestore(app);
+    void Promise.resolve(() => getAuth(app));
+    const testDoc = doc(firestore, 'coll/doc');
+    return getDoc(testDoc);
+  });
+
+  it('getDoc() before getAuth()', () => {
+    const firestore = getFirestore(app);
+    const testDoc = doc(firestore, 'coll/doc');
+    const promise = getDoc(testDoc);
+    getAuth(app);
+    return promise;
+  });
+
+  it('uses user from getAuth()', async () => {
+    const firestore = getFirestore(app);
+    const testDoc = doc(firestore, 'coll/doc');
+    void disableNetwork(firestore); // Go offline to enforce latency-compensation
+    void setDoc(testDoc, { foo: 'bar' });
+
+    const auth = getAuth(app);
+    void signInAnonymously(auth);
+
+    // setDoc() did not actually persist the document until the sign in attempt.
+    // Hence there was no user change and we can read the same document back.
+    const cachedDoc = await getDoc(testDoc);
+    expect(cachedDoc.exists()).to.be.true;
+  });
+
+  it('uses user from asynchronously loaded getAuth()', async () => {
+    const firestore = getFirestore(app);
+    const testDoc = doc(firestore, 'coll/doc');
+    void disableNetwork(firestore); // Go offline to enforce latency-compensation
+    void setDoc(testDoc, { foo: 'bar' });
+
+    void Promise.resolve().then(() => {
+      const auth = getAuth(app);
+      return signInAnonymously(auth);
+    });
+
+    // setDoc() did not actually persist the document until the sign in attempt.
+    // Hence there was no user change and we can read the same document back.
+    const cachedDoc = await getDoc(testDoc);
+    expect(cachedDoc.exists()).to.be.true;
+  });
+
+  it('uses user from getAuth()', async () => {
+    const firestore = getFirestore(app);
+    const testDoc = doc(firestore, 'coll/doc');
+    void disableNetwork(firestore); // Go offline to enforce latency-compensation
+    void setDoc(testDoc, { foo: 'bar' });
+
+    // Wait for the document. This waits for client initialization.
+    const cachedDoc = await getDoc(testDoc);
+    expect(cachedDoc.exists()).to.be.true;
+
+    const auth = getAuth(app);
+    void signInAnonymously(auth);
+
+    try {
+      await getDoc(testDoc);
+      expect.fail('Document should not have been found after user change');
+    } catch (e) {}
+  });
+
+  // eslint-disable-next-line no-restricted-properties
+  (typeof indexedDB !== 'undefined' ? describe : describe.skip)(
+    'with IndexedDB',
+    () => {
+      it('getAuth() before explicitly initializing Firestore', () => {
+        getAuth(app);
+        const firestore = getFirestore(app);
+        void enableIndexedDbPersistence(firestore);
+        const testDoc = doc(firestore, 'coll/doc');
+        return getDoc(testDoc);
+      });
+
+      it('explicitly initialize Firestore before getAuth()', () => {
+        const firestore = getFirestore(app);
+        void enableIndexedDbPersistence(firestore);
+        getAuth(app);
+        const testDoc = doc(firestore, 'coll/doc');
+        return getDoc(testDoc);
+      });
+
+      it('getFirestore() followed by getAuth() followed by explicitly initialization', () => {
+        const firestore = getFirestore(app);
+        getAuth(app);
+        void enableIndexedDbPersistence(firestore);
+        const testDoc = doc(firestore, 'coll/doc');
+        return getDoc(testDoc);
+      });
+    }
+  );
+});