fix(firestore): fix empty message reject inside transaction body

.changeset/spotty-bananas-fry.md

@@ -0,0 +1,5 @@
+---
+'@firebase/firestore': patch
+---
+
+Fixed a bug where a rejected promise with an empty message in a transaction would cause a timeout.

packages/firestore/src/core/transaction_runner.ts

@@ -112,8 +112,8 @@ export class TransactionRunner<T> {
     }
   }
 
-  private isRetryableTransactionError(error: Error): boolean {
-    if (error.name === 'FirebaseError') {
+  private isRetryableTransactionError(error: Error | undefined): boolean {
+    if (error?.name === 'FirebaseError') {
       // In transactions, the backend will fail outdated reads with FAILED_PRECONDITION and
       // non-matching document versions with ABORTED. These errors should be retried.
       const code = (error as FirestoreError).code;

packages/firestore/test/integration/api/transactions.test.ts

@@ -593,6 +593,19 @@ apiDescribe('Database transactions', persistence => {
     }
   );
 
+  it('runTransaction with empty message reject inside', () => {
+    return withTestDb(persistence, async db => {
+      try {
+        await runTransaction(db, () => {
+          return Promise.reject();
+        });
+        expect.fail('transaction should fail');
+      } catch (err) {
+        expect(err).to.be.undefined;
+      }
+    });
+  });
+
   describe('must return a promise:', () => {
     const noop = (): void => {
       /* -_- */