Cannot find .env file when running tests

[revosw]

I know this is not dotenv_flutter's fault but rather how rootBundle works in tests, but loading environment variables in an integration test is essential for the test to work like in the real world, and every person on the planet loading the .env file is going to encounter this problem.

I have an integration test that loads environment variables. Inside DotEnv().load(), eventually rootBundle.loadString(".env") is called. This throws the error FlutterError (Unable to load asset: .env). Any idea what may cause this?

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

void main() {
  IntegrationTestWidgetsFlutterBinding.ensureInitialized();

  group('end-to-end test', () {
    testWidgets('reads mailing list', (WidgetTester tester) async {
      IntegrationTestWidgetsFlutterBinding.ensureInitialized();
      // FlutterError (Unable to load asset: .env)
      final env = await rootBundle.loadString(".env");
      await app.main();
      await tester.pumpAndSettle();
    });
  });
}

pubspec.yaml

# ...rest of yaml file
  flutter:
    assets:
      - .env

The .env is located at the root of the project, it loads totally fine when running the app normally, but fails in tests

[revosw]

If I had just READ THE DOCUMENTATION, I would have seen the section about testing.

https://pub.dev/packages/flutter_dotenv#using-in-tests

My test now looks like this, and it works

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

void main() {
  IntegrationTestWidgetsFlutterBinding.ensureInitialized();

  group('end-to-end test', () {
    testWidgets('reads mailing list', (WidgetTester tester) async {
      IntegrationTestWidgetsFlutterBinding.ensureInitialized();
      // Now I can access environment variables from dotenv.env[]
      dotenv.testLoad(fileInput: File("./.env").readAsStringSync());
      await app.main();
      await tester.pumpAndSettle();
    });
  });
}