Avoid auth triggers if we haven't yet received the initial user. (#2137)

* Avoid auth triggers if we haven't yet received the initial user.

#2078 altered the
initial state of currentUser from undefined to not undefined, which
caused the if statement to unconditionally evaluate to true. This
results in a race condition that could cause some initial writes to the
database to be dropped.

Fixes #2135

* CHANGELOG update.

* Fix to be more like android

Author: rsgowman

packages/firestore/CHANGELOG.md

@@ -8,6 +8,8 @@
   data from disk.
 - [changed] Improved performance for queries with filters that only return a
   small subset of the documents in a collection.
+- [fixed] Fixed a race condition between authenticating and initializing
+  Firestore that could result in initial writes to the database being dropped.
 
 # 1.4.10
 - [changed] Transactions now perform exponential backoff before retrying.

packages/firestore/src/api/credentials.ts

@@ -156,6 +156,7 @@ export class FirebaseCredentialsProvider implements CredentialsProvider {
       }
     };
 
+    this.currentUser = this.getUser();
     this.tokenCounter = 0;
 
     // Will fire at least once where we set this.currentUser
@@ -209,10 +210,8 @@ export class FirebaseCredentialsProvider implements CredentialsProvider {
     assert(!this.changeListener, 'Can only call setChangeListener() once.');
     this.changeListener = changeListener;
 
-    // Fire the initial event, but only if we received the initial user
-    if (this.currentUser) {
-      changeListener(this.currentUser);
-    }
+    // Fire the initial event
+    changeListener(this.currentUser);
   }
 
   removeChangeListener(): void {