// Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

/**
 * @assertion In an unmigrated library, override checking is done using legacy
 * types. This means that an unmigrated library can bring together otherwise
 * incompatible methods. When choosing the most specific signature during
 * interface computation, all nullability and requiredness annotations are
 * ignored, and the [Never] type is treated as [Null].
 *
 * @description Check that if legacy class extends legacy class and implements
 * opted-in class, legacy field can be unassigned when corresponding parent
 * field is of non-nullable type.
 *
 * @author iarkh@unipro.ru
 */
// Requirements=nnbd-weak
// @dart=2.6

import "dart:async";
import "../../../../Utils/expect.dart";
import "override_checking_A01_opted_in_lib.dart";

class A extends B implements OPTED_NONNULLABLE_FIELD {}

class B {
  int i;
  Object o;
  Function f;
  FutureOr<int> fi;
}

main() {
  A a = A();
  Expect.isNull(a.i);
  Expect.isNull(a.o);
  Expect.isNull(a.f);
  Expect.isNull(a.fi);
}