LanguageFeatures/nnbd/override_checking_A01_CLASSPARAM_t12.dart

/*
 * 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 implements opted-in class, all
 * nullability annotations in the parent class are ignored in the child class
 * and child class type parameter can be [Null] even if parent class type
 * parameter is non-nullable.
 *
 * @author iarkh@unipro.ru
 */
// SharedOptions=--enable-experiment=non-nullable
// @dart=2.6

import "../../Utils/expect.dart";
import "override_checking_opted_in_lib.dart";

class A1<T extends Null> implements OPTED_NONNULLABLE_INT<T>      { dynamic getParamType() => typeOf<T>(); }
class A2<T extends Null> implements OPTED_NONNULLABLE_OBJECT<T>   { dynamic getParamType() => typeOf<T>(); }
class A3<T extends Null> implements OPTED_NONNULLABLE_FUNCTION<T> { dynamic getParamType() => typeOf<T>(); }

main() {
  Expect.equals(Null, A1().getParamType());
  Expect.equals(Null, A1<Null>().getParamType());

  Expect.equals(Null, A2().getParamType());
  Expect.equals(Null, A2<Null>().getParamType());

  Expect.equals(Null, A3().getParamType());
  Expect.equals(Null, A3<Null>().getParamType());
}