// 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 method can accept [null] argument if corresponding
 * parent method argument is of 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 B {
  void test_int     (int      i) { Expect.isNull(i); }
  void test_object  (Object   o) { Expect.isNull(o); }
  void test_function(Function f) { Expect.isNull(f); }
  void test_dynamic (dynamic  d) { Expect.isNull(d); }
  void test_futureOr(FutureOr f) { Expect.isNull(f); }
  void test_null    (Null     n) { Expect.isNull(n); }
}

class A extends B implements OPTED_NULLABLE_ARGS {}

main() {
  A a = A();
  a.test_int     (null);
  a.test_object  (null);
  a.test_dynamic (null);
  a.test_function(null);
  a.test_futureOr(null);
  a.test_null    (null);
}