LanguageFeatures/nnbd/weak/overriding/override_checking_A01_CLASSPARAM_t39.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 generic legacy class extends legacy class and
 * implements opted-in class, child class type parameter can be [Null] if parent
 * interface type parameter is [Never].
 *
 * @Issue 40389
 * @author iarkh@unipro.ru
 */
// Requirements=nnbd-weak
// @dart=2.6

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

class B<T> { dynamic getParamType() => typeOf<T>(); }
class A<T extends Null> extends B<T> implements OPTED_NEVER<T> {}

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