LanguageFeatures/nnbd/weak/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

// Requirements=nnbd-weak
// @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());
}