Fail more gracefully when opening IndexedDb fails in Firefox private browsing (#5396)

Author: dconeybe

.changeset/brown-dog-twirl.md

@@ -0,0 +1,5 @@
+---
+"@firebase/firestore": patch
+---
+
+Improved the error handling when opening IndexedDb fails in a Firefox private browsing session.

packages/firestore/src/local/simple_db.ts

@@ -322,6 +322,16 @@ export class SimpleDb {
                   'data for your app to start fresh.'
               )
             );
+          } else if (error.name === 'InvalidStateError') {
+            reject(
+              new FirestoreError(
+                Code.FAILED_PRECONDITION,
+                'Unable to open an IndexedDB connection. This could be due to running in a ' +
+                  'private browsing session on a browser whose private browsing sessions do not ' +
+                  'support IndexedDB: ' +
+                  error
+              )
+            );
           } else {
             reject(new IndexedDbTransactionError(action, error));
           }