Flutter tests - Having two Integration tests in a same group ()

Question

I'm trying to run two tests in a same group in one test file. If I split them into two separate test files, they are working fine. But if I add them in a group, the 2nd test fail with the error saying "TypeAdapter is already registered for the given id".

My app uses HiveDB and it sets up Hive boxes in the main.dart before launching the App. I understand that the 2nd test is also trying the same and fails because the setup is already done.

I followed this doc to setup and write integration tests.

Most of the youtube tutorials, medium articles, and other online resources explain so well on how to run one single test in a test file and they're outdated. I never found a resource having two tests in the same file yet.

• Here's my main.dart

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  await HiveDB.setup();
  runApp(App());
}

• test_driver/integration_test.dart

import 'package:integration_test/integration_test_driver.dart';

Future<void> main() => integrationDriver();

• test/app_test.dart

import 'package:flutter_test/flutter_test.dart';
import 'package:integration_test/integration_test.dart';

import 'package:integrationtestdemo/main.dart' as app;

void main() {
  IntegrationTestWidgetsFlutterBinding.ensureInitialized();

   group('Home screen tests', () {
    tearDown(() async {
      print("TearDown() -- called");
      await HiveDB.close();
    });

    testWidgets('Scenario # - loreum ipsum ...', (tester) async {
      // ARRANGE
      await app.main();
      await tester.pumpAndSettle();
      // ACT

      // ASSERT
      expect(1 + 3, 4);
    });

    testWidgets('Scenario #2', (tester) async {
      // ARRANGE
      await app.main();
      await tester.pumpAndSettle();
      // ACT

      // ASSERT
      expect(2 + 2, 4);
    });
  });
}

• The command I use to execute tests:

flutter drive --driver=.\test_driver\integration_test.dart --target=.\test\app_test.dart 

• Error I get:

══╡ EXCEPTION CAUGHT BY FLUTTER TEST FRAMEWORK ╞═════════════════
The following HiveError was thrown running a test:
There is already a TypeAdapter for typeId 1.

When the exception was thrown, this was the stack:
#0      TypeRegistryImpl.registerAdapter (package:hive/src/registry/type_registry_impl.dart:104:11)
#1      HiveDB.setup (package:occasionly/src/services/hive_db.dart:80:10)
<asynchronous suspension>

Could someone please help me here? I'm stuck on this for a long time and couldn't figure out a way to isolate the state between tests?

Answer 1

I have found a dirty trick to solve "TypeAdapter is already registered for the given id" this error

try to put it like this, and the error will not appear anymore

Hive.registerAdapter(YourAdapter(), override: true);

But I have no idea what is the possible impact could this argument do

Answer 2

I also faced the same issue, but I found a workaround by referring to this ERROR in flutter: widget_test.dart cannot detect MyApp(), you could try it.

testWidgets('Scenario #1', (tester) async {
      // ARRANGE
      await app.main();
      ...
});

testWidgets('Scenario #2', (tester) async {
      // ARRANGE
      await tester.pumpWidget(MyApp());
});