real_async_in_tests.dart

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

void main() async {
  LiveTestWidgetsFlutterBinding();
  Future outsideFuture;

  setUp(() {
    outsideFuture = Future.microtask(() {
      return 'outside';
    });
  });

  testWidgets("awaiting future with value from setUp works", (t) async {
    Future insideFuture = Future.microtask(() {
    return 'inside';
  });
}