LanguageFeatures/nnbd/overriding/override_checking_A01_CLASSPARAM_t16.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, child
 * class type parameter can be [Null] if parent class type parameter is
 * nullable.
 *
 * @author iarkh@unipro.ru
 */
// SharedOptions=--enable-experiment=non-nullable
// @dart=2.6

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

class A1<T extends Null> implements OPTED_NULLABLE         <T> { dynamic getParamType() => typeOf<T>(); }
class A2<T extends Null> implements OPTED_DYNAMIC          <T> { dynamic getParamType() => typeOf<T>(); }
class A3<T extends Null> implements OPTED_NULLABLE_INT     <T> { dynamic getParamType() => typeOf<T>(); }
class A4<T extends Null> implements OPTED_NULLABLE_OBJECT  <T> { dynamic getParamType() => typeOf<T>(); }
class A5<T extends Null> implements OPTED_NULLABLE_FUNCTION<T> { dynamic getParamType() => typeOf<T>(); }
class A6<T extends Null> implements OPTED_NULL             <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());

  Expect.equals(Null, A4      ().getParamType());
  Expect.equals(Null, A4<Null>().getParamType());

  Expect.equals(Null, A5      ().getParamType());
  Expect.equals(Null, A5<Null>().getParamType());

  Expect.equals(Null, A6      ().getParamType());
  Expect.equals(Null, A6<Null>().getParamType());
}