🐛 [cloud_firestore] old data retrieved if get is called just after a transaction when a stream is active #10153

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';

class TestBugWidget extends StatefulWidget {
  const TestBugWidget({super.key});

  @override
  State<TestBugWidget> createState() => _TestBugWidgetState();
}

class _TestBugWidgetState extends State<TestBugWidget> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Bug repro')),
      body: Column(children: [
        ListTile(
          title: const Text('Listen to the stream'),
          onTap: streamListen,
        ),
        ListTile(
          title: const Text('Update then Get'),
          onTap: updateThenGet,
        ),
        ListTile(
          title: const Text('Transact then Get'),
          onTap: transactThenGet,
        )
      ]),
    );
  }

  void streamListen() {
    FirebaseFirestore.instance
        .collection('test')
        .doc('test')
        .snapshots()
        .listen((event) {
      debugPrint('new test has arrived');
    });
  }

  Future<void> transactThenGet() async {
    final docRef = FirebaseFirestore.instance.collection("test").doc("test");
    var newPopulation;
    await FirebaseFirestore.instance.runTransaction((transaction) async {
      final snapshot = await transaction.get(docRef);
      final prevPopulation = snapshot.get("population");
      newPopulation = prevPopulation + 1;
      transaction.update(docRef, {"population": newPopulation});
    });
    Map<String, dynamic> updated = (await docRef.get()).data()!;
    debugPrint('Expecting : ${newPopulation.toString()}');
    debugPrint('Got : ${updated['population'].toString()}');
  }

  Future<void> updateThenGet() async {
    final docRef = FirebaseFirestore.instance.collection("test").doc("test");
    final snapshot = await docRef.get();
    final prevPopulation = snapshot.get("population");
    final newPopulation = prevPopulation + 1;
    await docRef.update({"population": newPopulation});
    Map<String, dynamic> updated = (await docRef.get()).data()!;
    debugPrint('Expecting : ${newPopulation.toString()}');
    debugPrint('Got : ${updated['population'].toString()}');
  }
}