LanguageFeatures/nnbd/weak/overriding/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.
///
/// @Issue 40398
/// @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_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());
}